silverbulletrx7.com Content
11-22-11, 10:36 AM
#1
www.silverbulletrx7.com
Thread Starter
silverbulletrx7.com Content
Not sure how many of you all know me but I was the creator of the silverbulletrx7 website. My name is Charles Saftner and I actually started this site before I bought my car in 1998. It was my first website that I created before getting into IT as my profession. Turned out web design wasn't my thing so I became a Product Manager. Anyway long story short I decided I didn't want to maintain my site any longer so let the domain lapse. Forums like this one seem to be the main place for info now with the exception of some of the bigger rx-7 sites. I just wasn't getting many e-mails like I did years ago and I figured nobody was really interested in the content. Much of it was outdated anyway as I have gotten near the end of my upgrade path with my car. (I'm now building a kit car called the K1 Attack http://www.attackforums.com/showthread.php?t=2823) Still, a few people have contacted me asking about it. It was nice to know a few people found value in it and missed it. So instead of letting it completely die I figured I'd post the content up here in this thread. I hope you all find it interesting even if some of it is a bit old.
To start I posted my logo and the pic of my car that was on my home page.
To start I posted my logo and the pic of my car that was on my home page.
11-22-11, 10:51 AM
#2
www.silverbulletrx7.com
Thread Starter
Upgrades Intro
The main bit of my site was general info on upgrades that I did. I never liked this original stuff much because it lacked detail. I think it needed to be a bit more of a how-to on each aspect instead of "look at what I did" list.
Intro: The Third generation Rx-7 is perhaps one of the hardest cars to upgrade safely. A great part of this is due to the unique nature of the rotary engine. Below I will offer some advice on some common and not so common upgrades. Doing things in the wrong order can lead to a blown engine. Proper maintenance is also a must. Certain things that are standard for a piston engine are a no go for the rotary. For example spark plugs must be replaced every 5-30K. This combined with Mazda's poor marketing led to the low sales of this car. However if you are a person that can pay attention to detail, you can enjoy more power per pound per dollar than just about any other car. A good part of this is because of the rotary engine. One of the main reasons this engine is so great is because it rotates (see picture). A piston engine looses a great deal of its energy changing the direction of travel of it's pistons. The rotary also has far fewer moving parts that cause friction.
Stats: Ever since I saw the first commercial for the Rx-7 back in 92 I wanted one. It was my dream car. My dream car started out as one of those cars that fell into the hands of a less knowledgeable person. It actually had about 5 previous owners. It already had it's engine replaced once due to incorrect modifications such as a piggyback computer chip designed only for a stock car. Great, but it wasn't stock. It took one and a half years to get it up to par and I'm still going. As I am not rich this was my daily driver for almost 5 years. Today I drive an Mx-3 daily but still take the 7 out about once a week as well as to the track. I enjoy driving it and see it as getting my moneys worth. Since I bought it I have put about 75K on the car, every mile of which was great.
Weight - 2750 with 3/4 tank of gas (2950 is about stock)
Horsepower - 295 heat soaked, expect +15 on the road
Torque - 260 (expect +5 to 10 on the road)
0 to 60 - Est. 4.5
1/4 Mile - Est. Mid 12s
MPG - 20.8 average, 28 highway, 7 track
Update> I still drive the car as much as I can and have almost 160K miles on it. My poor Mx-3 was totaled by my tenant at the time when he ran his truck in to it in my driveway. I replaced that with a 93 Nissan NX2000, which rusted all to hell. Now I drive a Tiburon daily. Heavy car compared to what I have been use to.
Included is a pic of my car when I first bought it.
Intro: The Third generation Rx-7 is perhaps one of the hardest cars to upgrade safely. A great part of this is due to the unique nature of the rotary engine. Below I will offer some advice on some common and not so common upgrades. Doing things in the wrong order can lead to a blown engine. Proper maintenance is also a must. Certain things that are standard for a piston engine are a no go for the rotary. For example spark plugs must be replaced every 5-30K. This combined with Mazda's poor marketing led to the low sales of this car. However if you are a person that can pay attention to detail, you can enjoy more power per pound per dollar than just about any other car. A good part of this is because of the rotary engine. One of the main reasons this engine is so great is because it rotates (see picture). A piston engine looses a great deal of its energy changing the direction of travel of it's pistons. The rotary also has far fewer moving parts that cause friction.
Stats: Ever since I saw the first commercial for the Rx-7 back in 92 I wanted one. It was my dream car. My dream car started out as one of those cars that fell into the hands of a less knowledgeable person. It actually had about 5 previous owners. It already had it's engine replaced once due to incorrect modifications such as a piggyback computer chip designed only for a stock car. Great, but it wasn't stock. It took one and a half years to get it up to par and I'm still going. As I am not rich this was my daily driver for almost 5 years. Today I drive an Mx-3 daily but still take the 7 out about once a week as well as to the track. I enjoy driving it and see it as getting my moneys worth. Since I bought it I have put about 75K on the car, every mile of which was great.
Weight - 2750 with 3/4 tank of gas (2950 is about stock)
Horsepower - 295 heat soaked, expect +15 on the road
Torque - 260 (expect +5 to 10 on the road)
0 to 60 - Est. 4.5
1/4 Mile - Est. Mid 12s
MPG - 20.8 average, 28 highway, 7 track
Update> I still drive the car as much as I can and have almost 160K miles on it. My poor Mx-3 was totaled by my tenant at the time when he ran his truck in to it in my driveway. I replaced that with a 93 Nissan NX2000, which rusted all to hell. Now I drive a Tiburon daily. Heavy car compared to what I have been use to.
Included is a pic of my car when I first bought it.
Last edited by GoodfellaFD3S; 11-24-11 at 09:26 PM.
11-22-11, 11:04 AM
#3
www.silverbulletrx7.com
Thread Starter
Upgrades Cosmetic
Wing: Without going into to much detail I wanted a wing that was less extreme than what I call the picnic basket handle wing seen on some Supras and more extreme than stock. I found the Racing Beat wing to be perfect. One thing to remember about getting a wing is that most are cosmetic only. They offer a negligible amount of down force. This includes the stock wing. If you want a wing that's actually functional take a look at the stock wing for the 1999+ RX-7s. It's not cheap though.
Wheels: When I bought my car it came with OZ rims which are crap. I replaced them with stock which were a full 10 lb. lighter per rim. Later I refinished my stock wheels by hand. After a long while I upgraded to the jspec 17" wheels. To learn about what you should worry about when upgrading your wheels or tires go here.
Steering wheel: I upgraded to a Mazdaspeed Nardi steering wheel from an MP3. Click the link for details and pictures.
Fog lights: The lighting on the 7 is poor at best and it needs fog lights. I started with PIAA Platinum's which were stolen. [$200] Next I went with Pilot. [$65] They are ok except for the fact the bulbs blow pretty often. Currently I have them mounted on custom aluminum brackets behind the bumper. Update: Along with the bumper I lost a fog light so now I have Road Boy lights. [$40 to $75] I got silver ones that look really great on my silver car. They are very nice for the price. Almost as good as my old PIAAs to be honest. They are very bright, the bulbs don't blow and the mounting brackets are also better than both my other sets. I highly recommend these lights.
Bumper: I have had three on my car since I got it in January of 98. First was the PFS bumper which you can see on my picture page. I really liked this bumper even though it was to low and often scraped the ground. I sold what was left of it when I had a little run in with a guard rail. Next was stock. Not bad except for all the little stuff that goes behind it. I didn't want to buy all of this over priced hardware so I zip tied it on until I got the Shogun bumper that you see above. I got it with a body kit but sold that because I didn't like it. However without the rest of the kit the bumper doesn't really follow the lines of the car. I got the factory mudguards which really looked great with the bumper. If you decide to get this bumper or already have it there is an important detail you need to know. Speeds much over 100 mph may rip the lip off due to the great down force it provides. To avoid this just don't go over 100. Just kidding! You will need to reinforce the connection between the lip and the bumper. I used super large washers on the connection screws. I have also seen extra brackets added in the air intake. Update: Thanx to a really fat raccoon my poor bumper was destroyed. I only had it on with the mudguards for one week. Oh well, I started to not like the look anyway. So back to stock I went. I might get the KnightSports bumper next.
Scuff Guards: These you can get at a Mazda dealer and look great on a silver car. See Picture! I got them at a good price from MazdaStuff.
Clear Corner Markers: I call these my rice corners. They were very cheap at about $70 for both front and rear sets. The fronts replaced yellow ones while the rears replaced red ones. The bulbs produce the needed color. I guess there wasn't much of a reason to add these but it was so easy and they do look nice on a silver car. However I don't think they would look right on other colored cars except for maybe white and black.
Front Turn Signals: These can be found at rx7store.net and cost $150. I got mine from somebody on eBay for closer to $100 though. Naturally I got clear lenses with the polished housings. I'll get some pictures up sometime.
Wax: I have been conducting tests on different waxes and have found some very interesting results. Here is how I have been doing my tests. I wax half of my car with one product and the other half with another straight down the center. I drive it every day so the protection gets a work out to be sure. I started by testing Prolong paint sealant against some popular brands like Liquid Glass, Mother's and Meguiar's. I was sure ProLong was a gimmick and that it wouldn't last against top of the line waxes. However I was tired of waxing my car so often because I hate doing it and I have read that waxes melt in the hot sun. Prolong is a sealant and offers a lifetime warranty on your new car's paint if you use Prolong from the start.
The results? Lasts twice as long, twice as easy to apply, twice as smooth and shiny and only costs twice as much. I will never go back to wax. So next I heard about another sealant called Zaino Bros' that can only be bought online. Zaino does suggest using their pre-cleaner before your first application but after this it's a breeze. This test took forever because the sealants last so darn long. From what I can tell the Zaino is doing better because it beads the water when I wash the car. Both still bead in the rain though. My current test is on another gimmick product called Nu Finish. The infomercials claim it lasts a year and can go through 52 car washes and still bead the water. It is also a sealant but at less than $5 I wonder if I should even put it on my car. Well I did. It actually out lasted Zaino however only slightly. It was also more difficult to apply because removing the extra was gumming up my rag. For now I'm sticking to Zaino but the bottom line is that wax isn't anything compared to sealant!!! Update: Prolong has been discontinued as far as I can tell. A few of the leading brands are starting to come out with sealants, which I will test.
Update>Thank god for that raccoon!
Wheels: When I bought my car it came with OZ rims which are crap. I replaced them with stock which were a full 10 lb. lighter per rim. Later I refinished my stock wheels by hand. After a long while I upgraded to the jspec 17" wheels. To learn about what you should worry about when upgrading your wheels or tires go here.
Steering wheel: I upgraded to a Mazdaspeed Nardi steering wheel from an MP3. Click the link for details and pictures.
Fog lights: The lighting on the 7 is poor at best and it needs fog lights. I started with PIAA Platinum's which were stolen. [$200] Next I went with Pilot. [$65] They are ok except for the fact the bulbs blow pretty often. Currently I have them mounted on custom aluminum brackets behind the bumper. Update: Along with the bumper I lost a fog light so now I have Road Boy lights. [$40 to $75] I got silver ones that look really great on my silver car. They are very nice for the price. Almost as good as my old PIAAs to be honest. They are very bright, the bulbs don't blow and the mounting brackets are also better than both my other sets. I highly recommend these lights.
Bumper: I have had three on my car since I got it in January of 98. First was the PFS bumper which you can see on my picture page. I really liked this bumper even though it was to low and often scraped the ground. I sold what was left of it when I had a little run in with a guard rail. Next was stock. Not bad except for all the little stuff that goes behind it. I didn't want to buy all of this over priced hardware so I zip tied it on until I got the Shogun bumper that you see above. I got it with a body kit but sold that because I didn't like it. However without the rest of the kit the bumper doesn't really follow the lines of the car. I got the factory mudguards which really looked great with the bumper. If you decide to get this bumper or already have it there is an important detail you need to know. Speeds much over 100 mph may rip the lip off due to the great down force it provides. To avoid this just don't go over 100. Just kidding! You will need to reinforce the connection between the lip and the bumper. I used super large washers on the connection screws. I have also seen extra brackets added in the air intake. Update: Thanx to a really fat raccoon my poor bumper was destroyed. I only had it on with the mudguards for one week. Oh well, I started to not like the look anyway. So back to stock I went. I might get the KnightSports bumper next.
Scuff Guards: These you can get at a Mazda dealer and look great on a silver car. See Picture! I got them at a good price from MazdaStuff.
Clear Corner Markers: I call these my rice corners. They were very cheap at about $70 for both front and rear sets. The fronts replaced yellow ones while the rears replaced red ones. The bulbs produce the needed color. I guess there wasn't much of a reason to add these but it was so easy and they do look nice on a silver car. However I don't think they would look right on other colored cars except for maybe white and black.
Front Turn Signals: These can be found at rx7store.net and cost $150. I got mine from somebody on eBay for closer to $100 though. Naturally I got clear lenses with the polished housings. I'll get some pictures up sometime.
Wax: I have been conducting tests on different waxes and have found some very interesting results. Here is how I have been doing my tests. I wax half of my car with one product and the other half with another straight down the center. I drive it every day so the protection gets a work out to be sure. I started by testing Prolong paint sealant against some popular brands like Liquid Glass, Mother's and Meguiar's. I was sure ProLong was a gimmick and that it wouldn't last against top of the line waxes. However I was tired of waxing my car so often because I hate doing it and I have read that waxes melt in the hot sun. Prolong is a sealant and offers a lifetime warranty on your new car's paint if you use Prolong from the start.
The results? Lasts twice as long, twice as easy to apply, twice as smooth and shiny and only costs twice as much. I will never go back to wax. So next I heard about another sealant called Zaino Bros' that can only be bought online. Zaino does suggest using their pre-cleaner before your first application but after this it's a breeze. This test took forever because the sealants last so darn long. From what I can tell the Zaino is doing better because it beads the water when I wash the car. Both still bead in the rain though. My current test is on another gimmick product called Nu Finish. The infomercials claim it lasts a year and can go through 52 car washes and still bead the water. It is also a sealant but at less than $5 I wonder if I should even put it on my car. Well I did. It actually out lasted Zaino however only slightly. It was also more difficult to apply because removing the extra was gumming up my rag. For now I'm sticking to Zaino but the bottom line is that wax isn't anything compared to sealant!!! Update: Prolong has been discontinued as far as I can tell. A few of the leading brands are starting to come out with sealants, which I will test.
Update>Thank god for that raccoon!
Last edited by GoodfellaFD3S; 11-24-11 at 09:27 PM.
11-22-11, 11:05 AM
#4
would be nice if more people gave write up based projects, it bores me going into a thread on someone's car just to see pictures of a bunch of random bolt on parts then pictures of them bolted on with a dyno sheet.
i prefer seeing threads based around DIY projects, in depth detail, inspiration. that is what i like to see and i'm sure what drew most people to your website.
but before you spend all day posting the content i would consider that it may not stay here. this is now a commercialized website owned by an investor company who doesn't care much for third party linking if they think it won't benefit them somehow.
i prefer seeing threads based around DIY projects, in depth detail, inspiration. that is what i like to see and i'm sure what drew most people to your website.
but before you spend all day posting the content i would consider that it may not stay here. this is now a commercialized website owned by an investor company who doesn't care much for third party linking if they think it won't benefit them somehow.
Last edited by RotaryEvolution; 11-22-11 at 11:07 AM.
11-22-11, 11:11 AM
#5
www.silverbulletrx7.com
Thread Starter
Well I'm not a vendor, just somebody posting my content, just like any other guy posting about their car projects. They can tear it down if they like tho.
11-22-11, 11:22 AM
#6
it was just an FYI, not digging on you as it doesn't bother me in the least. just rather not see you spend a few hours on it to get it torn down, perhaps ask one of the moderators where might be a good place for it all to be stored.
Last edited by RotaryEvolution; 11-22-11 at 11:24 AM.
11-22-11, 11:27 AM
#7
www.silverbulletrx7.com
Thread Starter
Upgrades Performance
Intake: There are a great many ways to upgrade this component. Many are just cone filters stuck on the ends of the hoses. This is worse than stock because they draw hot air from the engine compartment. Cold air induction is a must. If you want to upgrade the intercooler you almost have to replace the stock air box. Besides replacing the air box or just throwing on some cones there is one other good choice which is the Racing Beat intake. It replaces the crappy ducting which is the weakest part of the stock intake. Combine this with a K&N filter and you have a winner. Price is only about $100.
This was my first intake and served me well for many years. Another addition I did for the intake was enlarging the inlet in the nose for better air flow. For a template of my duct extension see this picture. If you plan on printing it you will need to do something like select half of it and select "print selection" from the print options because it won't fit on one sheet of paper. Another cheap way to go is by cutting holes in the bottom of the stock box, closing off the normal ducting and adding a heat shield. This has been discussed in great detail on the forum. My current intake is completely 100% custom fabricated. In addition to the intake I added an efini Y-pipe. It eliminates the hose coupling that is failure prone along with adjusting the angle of the blow-off valve attachment in an effort to clear the air passage. At around $250 it's probably not really worth buying but I figured I would treat myself. I'm guessing around a 2 hp gain although some say as much as 10.
Intercooler: The stock intercooler is a weak link to be sure so if your running your car hard and want more power but also want to prevent detonation you should upgrade. Not only is the stock IC small but it also doesn't have internal fins for heat transfer. There are many intercoolers that are readily available and worth buying, far more than when I was in the market. My basic choices that didn't involve relocating the battery were M2, GReddy, PFS and Pettit. In my opinion that is the order of their quality in terms of cooling. There is of course a price difference and for the average person any one will do so I went with GReddy because it's the cheapest and didn't require replacing the air box. I bought it used and much to my dismay it was missing a pipe.
As a temporary fix I used some PBC, as can be seen in the picture. Finding a place that offered 2 3/4 dia. piping wasn't easy but after a long search I found www.mandrelbending.com. They did a good job but their shipping is out of control. $21.00 for a one pound box bringing the total to fix this problem to $78. Another problem is that if you get this intercooler and also go with the RB intake the ducting provided won't work. It's crap anyway so I made my own using sheet metal. A few notes on intercoolers. Depth doesn't matter as much as area because most of the cooling an intercooler does is done in the first 1/2 inch. Another thing to consider is the fact that the intake for the intercooler is shared with the air intake. This can cause back flow which is air being sucked from the engine bay through the hot intercooler into the air intake. Although this is only really possible at low speeds I still recommend separating the intakes. Fans are a great idea and I'll probably add one soon. As for large SMICs like CWCs and M2s, which require relocating the battery I say that the intake duct is too small to feed enough air to such an intercooler to the point of increased cooling.
Only so much air can get through the opening so if the intercooler is monstrous in size the air will be flowing over it very slowly. Pressure drop may also be a concern. Who can forget the intercooler comparison that Sport Compact Car magazine did for their project Rx-7. It found no improvement with the M2 large over the medium. Now, a word on front mounts- Unless you are drag racing or concerned more with looks, these hinder air flow to the radiator and heat the air that it does get. For a car with cooling problems this is a bad idea. You can contest these ideas all you want but I know of people with cooling problems on the track with FMICs. It is well documented! Some people criticize the GReddy SMIC but with my ducting the top is cool to the touch even under track conditions. It is a great design.
Battery: Normal batteries seem to leak in my car. Click on the link to see what I did about it.
Exhaust: There are several choices here and "the best" really depends on you. When I got my car it had the old style GReddy exhaust on it which I really liked. 3" stainless is the best, even though my GReddy is mild and rusting to hell. I will eventually be custom fabbing my own exhaust. (Update: I have now completed my custom exhaust!!) Another part of the exhaust are the cats. The pre cat should be replaced with a down pipe if you haven't done this already. The stock pre-cat can get clogged when it gets old and if this happens it can cause an engine fire. I got a Stainless Steel pipe from ATR. I got my car tested for emissions and this modification didn't affect it at all. The last piece of the puzzle is the main cat. Many people replace this with a mid-pipe, which is an elimination of the cat just like the down pipe eliminates the pre-cat. It offers much more power up high but down low power suffers. I decided to go with a high-flow cat with 3" pipe from ATR. In addition to the power lost down low I also consider clean air important. A mid pipe is also much louder and can cause boost creep. I gained 10hp over the stock unit at the top end. I would urge everyone to consider sticking with a cat unless your car is strictly a track car.
Strut Brace: This comes standard on the R1 model. I have one made by GAB. I think it makes steering more responsive.
Sway Bar Mounts: The stock sway bar mounts are prone to failure under hard cornering and can actually cause damage to the frame in some cases. These problems are even more likely if you're auto-Xing or using R-compound tires for racing. When I noticed that one of my mounts was bent I upgraded to the CWC mounts. They are solid aluminum and attach to the chassis by both screwing it to the stock holes and clamping down on to the side, thus lessening the chance for cracks in the frame. They are also shorter so the sway bar is brought in away from the road. This is good for lowered cars.
Sway Bars: When it came time to buy a sway bar I found a lot of good choices however each one offered a different degree of stiffness. I couldn't decide which one would match well with my other planned suspension upgrades. This led me to believe the safe bet was an adjustable one. There were two choices, M2 and TriPoint Engineering. M2 decided that their kit was too expensive and wasn't profitable so I went with TriPoint's. The cost is nearly double that of a normal bar but I felt that the cost was worth it. The TriPoint bar is of the highest quality and installation was a breeze. (Nice for a change.) Initially I was going to buy an adjustable rear bar too made by Racing Beat but heard that some road racers completely remove the rear bar. I decided that if I needed it I could buy it later, which I did. After installing coilovers and the front bar I had pretty bad understeer so I bought the RB rear bar. This bar's install was not a breeze. First of all the red urethane bushings that were provided were too large for the stock mounts. I have read that one person shaved the bushings down but I bent the bushing mounts wider and re-drilled the holes. I reported this to RB and they were extremely responsive but despite the measurements I sent them they were not convinced that this is a problem with their kit. If you experienced a similar problem with your RB rear bar please contact RB so they know I'm not alone. Another problem I had with the bar was the two adjustment positions. The first one (stiffest) is in the same position as the stock bar's single hole while the second (softer but still stiffer than stock) is further out by about an inch. Due to my slightly thicker coilovers the bulky stock sway bar end link won't fit in the outer position. This sent me in to oversteer. I am planning on buying some rod ends to replace the stock links but have managed to get me car pretty netural by adjusting the front bar.
Trailing Arms: The 3rd gen Rx-7 can suffer from a condition known as wheel hop, which occurs during hard acceleration in first gear. Basically as the car applies torque to the wheels the suspension flexes a bit. When the wheels break loose the suspension un-flexes due to the reduced friction level. The process then repeats and produces a very violent vibration. This not only hurts performance but is also damaging to the car. The main point of flex are the compliant bushings in the trailing arms. Aftermarket Trailing arms such as the ones sold by Pettit, M2 or Rotary Extreme eliminate the stock bushing with a pillow ball joint. I went with Rotary Extreme. They use solid machined aluminum (some of the others use steel tubes), better pillow ***** and don't require modifications to accept the use of dust boots. There are other ways to reduce wheel hop as well like solid diff mounts or a diff brace but these things transfer more vibration to the chassis and this modification eliminates the problem in most cars.
Toe Links: Just as with the trailing arms I got from Rotary Extreme these toe links replace more of the compliant stock bushings with pillow *****. In this case the toe links control of all things... toe. According to M2 the Rx-7 can experience toe out in the rear under aggressive cornering and braking due to these bushings giving a little. Normally the novice driver should only brake in a straight line on the track but there are times when breaking in a turn can be needed. I got these links at a reduced price with the trailing arms so figured why not.
Brakes: If I were rich I would get something like the M2 big brake upgrade but I'm not and the stock brakes are really good on this car. There are a few things you can do to improve the stock brakes though. My stock rotors warped with no question. I believe the stock pads were the cause. I upgraded to Axxis pads and Brembo slotted rotors. Slotted rotors offer a slight advantage over stock because the slots help the pad in that glazed material is removed. There are other advantages too but I'll let you research that on your own. As for drilled rotors they are nice too but have a very high chance of cracking if you race. If somebody tells you differently they don't know jack! I have found the best price on new rotors on eBay. As for my pads I got Axxis Metal Master, which are a great street/race combo pad at a very reasonable price. On the street they don't have great bite, epically when cold but dusting is minimal and they are quiet. On the track they bite well and for my non-aggressive braking style they don't fade. I have experienced fade on tracks that are hard on brakes but it was manageable. They are durable and don't dust excessively on the track. However if you are racing your car more aggressively look at Hawk Blue pads. I'll be trying the new Axxis Ultimates next, which are their new and improved combo pad. Lastly I painted my calipers and polished the letters. No improvement in performance but they look great! I'll also be installing a 929 master cylinder, which is highly recommended with a big brake kit but also enhances the stock system. It is both longer and larger in diameter (1" compared to 7/8") compared to the stock unit.
Gauges: I have four gauges, two mounted on a dual A-pillar mount, one in a DIN panel and the boost on the Pettit column mount. I had Autometer gauges but the boost gauge wasn't on zero at zero boost. Total crap. Oh but wait... NASCAR uses them so they must be good... lol. I then bought a used HKS boost gauge and a VDO temp gauge (which looks better and costs less). Another good brand is SPI although they are a bit more expensive. Defi gauges are also good and look more like stock than any other brand. As for what gauges to get you NEED both a boost and a water temperature gauge. Without a boost gauge there is no way to tell if your car is running right. Water temp. is important because the stock gauge is nothing more than an idiot light and is non linear. If this gauge moves past center it's probably too late as the rotor housing will warp if over heated. To install this gauge you need to tap into the water filler neck. If you get the VDO gauge you might be able to use the pre tapped hole on the top by getting an adapter and a washer. E-mail me for details. Update: I have learned that many Rx-7s have a slightly different filler neck with the hole I used closer to the cap making my setup impossible. You can still get a gauge but will have to tap into the neck. Another choice is the coolant line for the TB but I suggest sticking with the filler neck.
I have also been getting many questions on where to get VDO gauges and what type to buy. I got mine from summit racing. I chose the Vision series with 96" of tubing. The length of the tubing is fixed on these gauges so it can't be made longer or shorter. If you want to go through the fender get 96". If you want to go through the fire wall go with 72". Another gauge many people get is Air/Fuel ratio. I did this as well as I am getting close to the limit of the stock fuel system and wanted to keep an eye on things. There are many people that say this gauge is worthless and it is... for tuning your car. Just like the water temp gauge it will let you know if there is a problem. There aren't many choices for this gauge. Many A/F meters are boxes with lights instead of a round gauge. Cyberdyne and Autometer are two of the only choices. Cyberdyne had vertical lights that doesn't look good to me so I bit the Silver Bullet and bought an Autometer product. Look for readings around .84-.86 volts, which is on the rich side for these gauges. Under 3K RPM and under vacuum expect the reading to oscillate up and down. Although this is annoying it is normal and is just the computer operating in closed loop mode in order to find the best ratio. At idle expect full lean. Oh and I painted the bezel black because the silver was too much. Lastly I mounted a 46mm HKS temp gauge in a DIN panel above my stereo. (It's a high tec Pioneer cassette player.) I'm having some problems hooking it up due to a missing sender unit mount that was suppose to be in the package. I plan on using the RB adapter though that is basically an aluminum block the goes under the oil filter pedestal. It is designed for a second gen Rx-7 but can be used in a third gen with a bit of work. For more detail check out my buddy's Chris' site.
Clutch: When I bought my car it came with a CenterForce dual friction clutch. What a POS! It slips randomly when fully engaged, requires tremendous pedal pressure and has a small engagement area, which all together makes for a jerky ride if you get lazy. If you are thinking of upgrading your clutch go with an ACT. They are considered by most to be the best. Keep in mind that the stock clutch on this car is very nice so don't upgrade unless it's broken or you have lots of power... or if you drag race. Drag racing places higher demands on a clutch regardless of your power levels.
Radiator: Well I wasn't planning to do this upgrade as soon as I did but a lost screw got wedged between my fan and radiator so I had to do something. I decided to upgrade instead of spending my time putting in a stock part. I mean, what's the point in doing that? If I'm going to spend time and money I might as well upgrade. Unfortunately I didn't have time to price shop or do much research. I ended up with a Mazdacomp radiator. It's all aluminum and is 1 1/2 inches thick instead of 1 inch. I won't go into my adventures of installing it so if you want some more info just e-mail me. In the end I see slightly lower temps by about 5 deg. I think I might see bigger benefits when I'm closer to the limits like at the track. I guess I'll find out next season.
Radiator Hose: I upgraded to metal radiator hoses by Cool-Flex. Click the link for info.
AST: My plastic Air Separator Tank broke at the point where the hose to the Filler neck connects. I was very lucky my car didn't over heat. So now I have done what I should have done earlier. I called Pettit and bought their aluminum AST. Some people get the AST elimination kit. It is cheaper but there are rumors that without the AST small bubbles won't be filtered out. These can get lodged in the channels cooling the rotors causing a hot spot thus warping the rotors. I'm not sure I believe this but the way I see it is that Mazda put the AST in there for a reason.
Silicone Hose Job: This is a typical reliability upgrade that involves replacing the 70 some rubber vacuum hoses with silicone hoses. The rubber ones are very failure prone and normally result in low boost. Be warned that if you attempt this upgrade yourself it is very difficult. Only the most experienced users should attempt it. I paid somebody to do it because I was owed some free labor. Big mistake but when wasn't taking my car someplace other than KD Rotary a bad idea?
Computer: This is the most important upgrade and is the difference between going fast and blowing an engine. A general rule to follow is that if you do more than two of the following, you need to upgrade. The upgrades are mid pipe, down pipe, intake and exhaust. There are three main choices here. One is the PFS setup. This takes the readings fed too (or is it after) the stock computer and changes them. This I don't like. In my mind it is working against the stock computer instead of with it however it can work great if tuned properly. (Even then it can have grounding and ignition issues.) Tuning is the major advantage with this setup. If you get a key pad and have a laptop you can create your own fuel curves. Many people have also reported that the computer simply does not work as it should no matter how it is tuned. Even Peter has admitted his computer doesn't work on later models like 95s. There is also a high end problem where the engine is basically turned off. I'd go in to more detail but I'm just going to say, "don't get this computer!"
The second choice is getting a computer upgrade. Pettit and M2 along with some other places offer this service. Basically it involves removing two of the chips from the computer and replacing them with a bunch of new chips. This setup works great. The only drawback is that if you do a major new upgrade you may need to replace one of the chips which will run you $50. This is the choice I made and cost me $800. BTW this is much different than those other chips you can buy from little ads in magazines. Those are total crap for this car! Trust me on this one, my car had one from the first owner. Anyway the difference between the Pettit and M2 is that Pettit tunes theirs for 93 octane while M2 uses more conservative fuel maps for Ca 91 gas.
A new choice that wasn't available when I got my Pettit is the Apexi PFC. This is great because it is a stand alone unit that completely replaces the old computer and the 3K hesitation. It is adjustable like the PFS PMS but doesn't have the problems. It is the best and even though it costs as much as the PFS it is worth the money. It has readouts of just about everything like boost, water temp, and injector duty%. I would invest in one but it does operate the air pump in a way that decreases catalytic converter life. However I may be forced to get one because the Pettit ECU does not allow for 1300 seconday injectors, which are required if I want to surpass 300 hp at the wheels.
Boost Control: Yet another advantage the PFC computer has over the Pettit unit is the ability to adjust boost levels and store two pre-set levels that can be quickly alternated. Well I guess I'm a die hard Pettit ECU fan because I opted for a stand along boost controller. Assuming you have the stock twins there are two methods I suggest. One is a manual valve spliced in to the waste gate control line. Such a valve can be purchased at hardware stores and allows you to adjust the boost manually. The other is the GReddy profec b. The are other boost controllers out there but for this application there simply is no other acceptable choice. It has two settings and what is basically a speed ****, which controls the speed at which the unit adjusts boost. I have the older version. The newer version is digital. Some people have reported problem with the new version but I haven't looked in to it much.
Turbo Timer: This is a frequently misunderstood device. It is designed to let your car idle after a hard drive so that oil doesn't bake onto the burning hot turbo bushings. (Known as coking) However if a turbo timer is used after normal driving it is of no benifit and actually does nothing but burn gas and heat up the engine. While a car idles the engine temps rise until the fans turn on. For the Rx-7 normal operating temp is between 180 and 220. There is no need to heat the engine up to 220 for no reason. A GReddy unit can with my car and it mostly comes in handy to warm up my car while I leave the car unattended. Both the profec b and the turbo timer along with an oil temp gauge are mounted in a Blitz DIN panel. I thought this would be easy but it was far from it. I would have been better off fabbing a custom unit. First of all the profec b is thicker than the slots on this panel. In addition both the profec and the timer were wider. I had to carefully cut the darn thing up. Not only that but the panel required a spacer/bezel because it is too small. The picture on the box shows it mounted in an Rx-7 with a very nice bezel so why did I have to create one myself? I should have sold this thing since it is discontinued and fetches a pretty penny.
Fuel System: Perhaps the one biggest drawback of the Pettit chip is that it can't be tuned for larger injectors. Pettit says they are developing a chip for 1300 cc injectors but I can't wait forever. I have however upgraded the stock fuel pump. The best option it to get a Denso pump from a late model Supra. It is a drop in unit and is of higher quality than many of the other pumps you can buy. The stock pump is good for up to about 300 to 350 at the wheels. Mine actually started to fail at a track event but I already had the new pump waiting at home so it wasn't a big deal. You can find these pumps used for about $100 however I bought mine new. The lowest price I could find was at www.partznet.com for $180 but got quotes as high as $250. I also bought the little mesh bag that goes over the pickup. It's angle is slightly better, which helps reduce fuel starvation during fuel slosh in hard left turns. It was part number 2321746110.
Ignition: There are a lot of misconceptions here so read carefully. I have done my research in this area. Lets start with upgraded ignition like the ones offered by Crane and Jacobs. Do not buy these units. They offer no improvement over stock. Many racers use the stock system for their cars with huge hp levels. I have also seen these systems cause problems that led to burned up turbos. Even newr units that have come to market like AEM have serious problems such as over heating and turning off. If you must get a system the only real choice is the HKS Twin Power unit. It's additional performance is questionable but it is a quality unit. It is mostly proven to deliver consistent power under higher boost levels.
Next is plug wires. One popular brand to avoid is Magnecor. They sell based on brand recognition, just like Fram filters, which should also be avoided. These wires have higher resistance with higher levels of EM interference that can mess with your radio and computer. 10 mm Magnecor wires in particular cause problems for many owners. I'm not entirely sure why because many people report positive results so it might be a problem with the boots sealing properly. Jacobs wires also have a flaw which is that their boots can come off of the plug. I bought a set of Accel wires, which served me well for many miles. Taylor is another great brand that many owners use with success. I recently bought a set of MSD wires because it looked like they had superior quality however I was disappointed to see that fitment was a huge issue and that the advertised "separate conductor crimp tabs" was completely false advertising! Most drivers seem to be sticking with stock NGK wires. They have greater resistance but then again resistance is mostly a selling ploy and does not make a plug wire good or bad. One other popular choice are the wires sold by Racing Beat. I have been unable to find any data on these wires but doubt that at their $100 price they are worth buying.
Lastly and most importantly is the plug. I am conducting extensive research on this component which can be seen here.
929 Master Cylinder: This is the device that forces brake fluid to the pistons and stops the car. The Master Cylinder (MC) from the Mazda 929 is slightly larger at 1" instead of the stock 15/16th. Slight modifications are required, which I trusted to KD Rotary. (I hate fluids.) However it should be easy for most people with the right tools. For a complete description go here. http://www.negative-camber.org/crispyrx7/929.htm This is the prefered upgrade if you move to a big brake kit but even with stock brakes it creates a firmer pedal feel. I have stock brakes but when I saw one of these brand new on eBay for about $45 I jumped on it. My stock one was getting old anyway. Well don't expect to repeat my luck as these normally sell for over $100.
Dual Oil Coolers: About 30% of the Rx-7's cooling is performed by the oil system and with a track driven car cooling becomes critical. My car was not an R1 that comes with dual coolers from the factory so I figured it was time to upgrade. Before doing so I installed an oil temp gauge so I could see the difference. Wow, my temps were hot hot HOT. I won't quote them because depending on where you mount your sender unit your temps will vary a lot. Anyway after installing the coolers my temps dropped big time. So which kit did I choose? Well I looked at several including the now unattainable Crooked Willow kit to a GReedy kit from Japan. I went with a slightly more expensive kit though and got the Rotary Extreme kit. I saw several advantages in this kit including how the hoses from the coolers exit from the top of the coolers instead of the bottom as well as the owner's (Chuck) high standards for quality. This kit uses top notch hoses and doesn't have the reported problems with the thermostat that the CW kit did. I'm sure I will be happy with this kit. It could use some ducts though. You may also wish to check out Gotham Racing's new kit.
What's Next?: Lets just say I have a lot of parts sitting around including a vented hood and 99 spec lip.
Update on Sway bars>That darn RB rear bar continued to give me problems so I eventually sold it in favor of a MS one. Talk about impossible to find. I eventually bought one from yahoo auctions Japan through a 3rd party. Now my car is finally the way I like it, just a bit of understeer in the softest position in the rear bar and middle on the front.
Well anyway that is mostly just general junk. I'll start posting some of my better stuff a bit later where I actually talk about a specific component in a more how-to format.
This was my first intake and served me well for many years. Another addition I did for the intake was enlarging the inlet in the nose for better air flow. For a template of my duct extension see this picture. If you plan on printing it you will need to do something like select half of it and select "print selection" from the print options because it won't fit on one sheet of paper. Another cheap way to go is by cutting holes in the bottom of the stock box, closing off the normal ducting and adding a heat shield. This has been discussed in great detail on the forum. My current intake is completely 100% custom fabricated. In addition to the intake I added an efini Y-pipe. It eliminates the hose coupling that is failure prone along with adjusting the angle of the blow-off valve attachment in an effort to clear the air passage. At around $250 it's probably not really worth buying but I figured I would treat myself. I'm guessing around a 2 hp gain although some say as much as 10.
Intercooler: The stock intercooler is a weak link to be sure so if your running your car hard and want more power but also want to prevent detonation you should upgrade. Not only is the stock IC small but it also doesn't have internal fins for heat transfer. There are many intercoolers that are readily available and worth buying, far more than when I was in the market. My basic choices that didn't involve relocating the battery were M2, GReddy, PFS and Pettit. In my opinion that is the order of their quality in terms of cooling. There is of course a price difference and for the average person any one will do so I went with GReddy because it's the cheapest and didn't require replacing the air box. I bought it used and much to my dismay it was missing a pipe.
As a temporary fix I used some PBC, as can be seen in the picture. Finding a place that offered 2 3/4 dia. piping wasn't easy but after a long search I found www.mandrelbending.com. They did a good job but their shipping is out of control. $21.00 for a one pound box bringing the total to fix this problem to $78. Another problem is that if you get this intercooler and also go with the RB intake the ducting provided won't work. It's crap anyway so I made my own using sheet metal. A few notes on intercoolers. Depth doesn't matter as much as area because most of the cooling an intercooler does is done in the first 1/2 inch. Another thing to consider is the fact that the intake for the intercooler is shared with the air intake. This can cause back flow which is air being sucked from the engine bay through the hot intercooler into the air intake. Although this is only really possible at low speeds I still recommend separating the intakes. Fans are a great idea and I'll probably add one soon. As for large SMICs like CWCs and M2s, which require relocating the battery I say that the intake duct is too small to feed enough air to such an intercooler to the point of increased cooling.
Only so much air can get through the opening so if the intercooler is monstrous in size the air will be flowing over it very slowly. Pressure drop may also be a concern. Who can forget the intercooler comparison that Sport Compact Car magazine did for their project Rx-7. It found no improvement with the M2 large over the medium. Now, a word on front mounts- Unless you are drag racing or concerned more with looks, these hinder air flow to the radiator and heat the air that it does get. For a car with cooling problems this is a bad idea. You can contest these ideas all you want but I know of people with cooling problems on the track with FMICs. It is well documented! Some people criticize the GReddy SMIC but with my ducting the top is cool to the touch even under track conditions. It is a great design.
Battery: Normal batteries seem to leak in my car. Click on the link to see what I did about it.
Exhaust: There are several choices here and "the best" really depends on you. When I got my car it had the old style GReddy exhaust on it which I really liked. 3" stainless is the best, even though my GReddy is mild and rusting to hell. I will eventually be custom fabbing my own exhaust. (Update: I have now completed my custom exhaust!!) Another part of the exhaust are the cats. The pre cat should be replaced with a down pipe if you haven't done this already. The stock pre-cat can get clogged when it gets old and if this happens it can cause an engine fire. I got a Stainless Steel pipe from ATR. I got my car tested for emissions and this modification didn't affect it at all. The last piece of the puzzle is the main cat. Many people replace this with a mid-pipe, which is an elimination of the cat just like the down pipe eliminates the pre-cat. It offers much more power up high but down low power suffers. I decided to go with a high-flow cat with 3" pipe from ATR. In addition to the power lost down low I also consider clean air important. A mid pipe is also much louder and can cause boost creep. I gained 10hp over the stock unit at the top end. I would urge everyone to consider sticking with a cat unless your car is strictly a track car.
Strut Brace: This comes standard on the R1 model. I have one made by GAB. I think it makes steering more responsive.
Sway Bar Mounts: The stock sway bar mounts are prone to failure under hard cornering and can actually cause damage to the frame in some cases. These problems are even more likely if you're auto-Xing or using R-compound tires for racing. When I noticed that one of my mounts was bent I upgraded to the CWC mounts. They are solid aluminum and attach to the chassis by both screwing it to the stock holes and clamping down on to the side, thus lessening the chance for cracks in the frame. They are also shorter so the sway bar is brought in away from the road. This is good for lowered cars.
Sway Bars: When it came time to buy a sway bar I found a lot of good choices however each one offered a different degree of stiffness. I couldn't decide which one would match well with my other planned suspension upgrades. This led me to believe the safe bet was an adjustable one. There were two choices, M2 and TriPoint Engineering. M2 decided that their kit was too expensive and wasn't profitable so I went with TriPoint's. The cost is nearly double that of a normal bar but I felt that the cost was worth it. The TriPoint bar is of the highest quality and installation was a breeze. (Nice for a change.) Initially I was going to buy an adjustable rear bar too made by Racing Beat but heard that some road racers completely remove the rear bar. I decided that if I needed it I could buy it later, which I did. After installing coilovers and the front bar I had pretty bad understeer so I bought the RB rear bar. This bar's install was not a breeze. First of all the red urethane bushings that were provided were too large for the stock mounts. I have read that one person shaved the bushings down but I bent the bushing mounts wider and re-drilled the holes. I reported this to RB and they were extremely responsive but despite the measurements I sent them they were not convinced that this is a problem with their kit. If you experienced a similar problem with your RB rear bar please contact RB so they know I'm not alone. Another problem I had with the bar was the two adjustment positions. The first one (stiffest) is in the same position as the stock bar's single hole while the second (softer but still stiffer than stock) is further out by about an inch. Due to my slightly thicker coilovers the bulky stock sway bar end link won't fit in the outer position. This sent me in to oversteer. I am planning on buying some rod ends to replace the stock links but have managed to get me car pretty netural by adjusting the front bar.
Trailing Arms: The 3rd gen Rx-7 can suffer from a condition known as wheel hop, which occurs during hard acceleration in first gear. Basically as the car applies torque to the wheels the suspension flexes a bit. When the wheels break loose the suspension un-flexes due to the reduced friction level. The process then repeats and produces a very violent vibration. This not only hurts performance but is also damaging to the car. The main point of flex are the compliant bushings in the trailing arms. Aftermarket Trailing arms such as the ones sold by Pettit, M2 or Rotary Extreme eliminate the stock bushing with a pillow ball joint. I went with Rotary Extreme. They use solid machined aluminum (some of the others use steel tubes), better pillow ***** and don't require modifications to accept the use of dust boots. There are other ways to reduce wheel hop as well like solid diff mounts or a diff brace but these things transfer more vibration to the chassis and this modification eliminates the problem in most cars.
Toe Links: Just as with the trailing arms I got from Rotary Extreme these toe links replace more of the compliant stock bushings with pillow *****. In this case the toe links control of all things... toe. According to M2 the Rx-7 can experience toe out in the rear under aggressive cornering and braking due to these bushings giving a little. Normally the novice driver should only brake in a straight line on the track but there are times when breaking in a turn can be needed. I got these links at a reduced price with the trailing arms so figured why not.
Brakes: If I were rich I would get something like the M2 big brake upgrade but I'm not and the stock brakes are really good on this car. There are a few things you can do to improve the stock brakes though. My stock rotors warped with no question. I believe the stock pads were the cause. I upgraded to Axxis pads and Brembo slotted rotors. Slotted rotors offer a slight advantage over stock because the slots help the pad in that glazed material is removed. There are other advantages too but I'll let you research that on your own. As for drilled rotors they are nice too but have a very high chance of cracking if you race. If somebody tells you differently they don't know jack! I have found the best price on new rotors on eBay. As for my pads I got Axxis Metal Master, which are a great street/race combo pad at a very reasonable price. On the street they don't have great bite, epically when cold but dusting is minimal and they are quiet. On the track they bite well and for my non-aggressive braking style they don't fade. I have experienced fade on tracks that are hard on brakes but it was manageable. They are durable and don't dust excessively on the track. However if you are racing your car more aggressively look at Hawk Blue pads. I'll be trying the new Axxis Ultimates next, which are their new and improved combo pad. Lastly I painted my calipers and polished the letters. No improvement in performance but they look great! I'll also be installing a 929 master cylinder, which is highly recommended with a big brake kit but also enhances the stock system. It is both longer and larger in diameter (1" compared to 7/8") compared to the stock unit.
Gauges: I have four gauges, two mounted on a dual A-pillar mount, one in a DIN panel and the boost on the Pettit column mount. I had Autometer gauges but the boost gauge wasn't on zero at zero boost. Total crap. Oh but wait... NASCAR uses them so they must be good... lol. I then bought a used HKS boost gauge and a VDO temp gauge (which looks better and costs less). Another good brand is SPI although they are a bit more expensive. Defi gauges are also good and look more like stock than any other brand. As for what gauges to get you NEED both a boost and a water temperature gauge. Without a boost gauge there is no way to tell if your car is running right. Water temp. is important because the stock gauge is nothing more than an idiot light and is non linear. If this gauge moves past center it's probably too late as the rotor housing will warp if over heated. To install this gauge you need to tap into the water filler neck. If you get the VDO gauge you might be able to use the pre tapped hole on the top by getting an adapter and a washer. E-mail me for details. Update: I have learned that many Rx-7s have a slightly different filler neck with the hole I used closer to the cap making my setup impossible. You can still get a gauge but will have to tap into the neck. Another choice is the coolant line for the TB but I suggest sticking with the filler neck.
I have also been getting many questions on where to get VDO gauges and what type to buy. I got mine from summit racing. I chose the Vision series with 96" of tubing. The length of the tubing is fixed on these gauges so it can't be made longer or shorter. If you want to go through the fender get 96". If you want to go through the fire wall go with 72". Another gauge many people get is Air/Fuel ratio. I did this as well as I am getting close to the limit of the stock fuel system and wanted to keep an eye on things. There are many people that say this gauge is worthless and it is... for tuning your car. Just like the water temp gauge it will let you know if there is a problem. There aren't many choices for this gauge. Many A/F meters are boxes with lights instead of a round gauge. Cyberdyne and Autometer are two of the only choices. Cyberdyne had vertical lights that doesn't look good to me so I bit the Silver Bullet and bought an Autometer product. Look for readings around .84-.86 volts, which is on the rich side for these gauges. Under 3K RPM and under vacuum expect the reading to oscillate up and down. Although this is annoying it is normal and is just the computer operating in closed loop mode in order to find the best ratio. At idle expect full lean. Oh and I painted the bezel black because the silver was too much. Lastly I mounted a 46mm HKS temp gauge in a DIN panel above my stereo. (It's a high tec Pioneer cassette player.) I'm having some problems hooking it up due to a missing sender unit mount that was suppose to be in the package. I plan on using the RB adapter though that is basically an aluminum block the goes under the oil filter pedestal. It is designed for a second gen Rx-7 but can be used in a third gen with a bit of work. For more detail check out my buddy's Chris' site.
Clutch: When I bought my car it came with a CenterForce dual friction clutch. What a POS! It slips randomly when fully engaged, requires tremendous pedal pressure and has a small engagement area, which all together makes for a jerky ride if you get lazy. If you are thinking of upgrading your clutch go with an ACT. They are considered by most to be the best. Keep in mind that the stock clutch on this car is very nice so don't upgrade unless it's broken or you have lots of power... or if you drag race. Drag racing places higher demands on a clutch regardless of your power levels.
Radiator: Well I wasn't planning to do this upgrade as soon as I did but a lost screw got wedged between my fan and radiator so I had to do something. I decided to upgrade instead of spending my time putting in a stock part. I mean, what's the point in doing that? If I'm going to spend time and money I might as well upgrade. Unfortunately I didn't have time to price shop or do much research. I ended up with a Mazdacomp radiator. It's all aluminum and is 1 1/2 inches thick instead of 1 inch. I won't go into my adventures of installing it so if you want some more info just e-mail me. In the end I see slightly lower temps by about 5 deg. I think I might see bigger benefits when I'm closer to the limits like at the track. I guess I'll find out next season.
Radiator Hose: I upgraded to metal radiator hoses by Cool-Flex. Click the link for info.
AST: My plastic Air Separator Tank broke at the point where the hose to the Filler neck connects. I was very lucky my car didn't over heat. So now I have done what I should have done earlier. I called Pettit and bought their aluminum AST. Some people get the AST elimination kit. It is cheaper but there are rumors that without the AST small bubbles won't be filtered out. These can get lodged in the channels cooling the rotors causing a hot spot thus warping the rotors. I'm not sure I believe this but the way I see it is that Mazda put the AST in there for a reason.
Silicone Hose Job: This is a typical reliability upgrade that involves replacing the 70 some rubber vacuum hoses with silicone hoses. The rubber ones are very failure prone and normally result in low boost. Be warned that if you attempt this upgrade yourself it is very difficult. Only the most experienced users should attempt it. I paid somebody to do it because I was owed some free labor. Big mistake but when wasn't taking my car someplace other than KD Rotary a bad idea?
Computer: This is the most important upgrade and is the difference between going fast and blowing an engine. A general rule to follow is that if you do more than two of the following, you need to upgrade. The upgrades are mid pipe, down pipe, intake and exhaust. There are three main choices here. One is the PFS setup. This takes the readings fed too (or is it after) the stock computer and changes them. This I don't like. In my mind it is working against the stock computer instead of with it however it can work great if tuned properly. (Even then it can have grounding and ignition issues.) Tuning is the major advantage with this setup. If you get a key pad and have a laptop you can create your own fuel curves. Many people have also reported that the computer simply does not work as it should no matter how it is tuned. Even Peter has admitted his computer doesn't work on later models like 95s. There is also a high end problem where the engine is basically turned off. I'd go in to more detail but I'm just going to say, "don't get this computer!"
The second choice is getting a computer upgrade. Pettit and M2 along with some other places offer this service. Basically it involves removing two of the chips from the computer and replacing them with a bunch of new chips. This setup works great. The only drawback is that if you do a major new upgrade you may need to replace one of the chips which will run you $50. This is the choice I made and cost me $800. BTW this is much different than those other chips you can buy from little ads in magazines. Those are total crap for this car! Trust me on this one, my car had one from the first owner. Anyway the difference between the Pettit and M2 is that Pettit tunes theirs for 93 octane while M2 uses more conservative fuel maps for Ca 91 gas.
A new choice that wasn't available when I got my Pettit is the Apexi PFC. This is great because it is a stand alone unit that completely replaces the old computer and the 3K hesitation. It is adjustable like the PFS PMS but doesn't have the problems. It is the best and even though it costs as much as the PFS it is worth the money. It has readouts of just about everything like boost, water temp, and injector duty%. I would invest in one but it does operate the air pump in a way that decreases catalytic converter life. However I may be forced to get one because the Pettit ECU does not allow for 1300 seconday injectors, which are required if I want to surpass 300 hp at the wheels.
Boost Control: Yet another advantage the PFC computer has over the Pettit unit is the ability to adjust boost levels and store two pre-set levels that can be quickly alternated. Well I guess I'm a die hard Pettit ECU fan because I opted for a stand along boost controller. Assuming you have the stock twins there are two methods I suggest. One is a manual valve spliced in to the waste gate control line. Such a valve can be purchased at hardware stores and allows you to adjust the boost manually. The other is the GReddy profec b. The are other boost controllers out there but for this application there simply is no other acceptable choice. It has two settings and what is basically a speed ****, which controls the speed at which the unit adjusts boost. I have the older version. The newer version is digital. Some people have reported problem with the new version but I haven't looked in to it much.
Turbo Timer: This is a frequently misunderstood device. It is designed to let your car idle after a hard drive so that oil doesn't bake onto the burning hot turbo bushings. (Known as coking) However if a turbo timer is used after normal driving it is of no benifit and actually does nothing but burn gas and heat up the engine. While a car idles the engine temps rise until the fans turn on. For the Rx-7 normal operating temp is between 180 and 220. There is no need to heat the engine up to 220 for no reason. A GReddy unit can with my car and it mostly comes in handy to warm up my car while I leave the car unattended. Both the profec b and the turbo timer along with an oil temp gauge are mounted in a Blitz DIN panel. I thought this would be easy but it was far from it. I would have been better off fabbing a custom unit. First of all the profec b is thicker than the slots on this panel. In addition both the profec and the timer were wider. I had to carefully cut the darn thing up. Not only that but the panel required a spacer/bezel because it is too small. The picture on the box shows it mounted in an Rx-7 with a very nice bezel so why did I have to create one myself? I should have sold this thing since it is discontinued and fetches a pretty penny.
Fuel System: Perhaps the one biggest drawback of the Pettit chip is that it can't be tuned for larger injectors. Pettit says they are developing a chip for 1300 cc injectors but I can't wait forever. I have however upgraded the stock fuel pump. The best option it to get a Denso pump from a late model Supra. It is a drop in unit and is of higher quality than many of the other pumps you can buy. The stock pump is good for up to about 300 to 350 at the wheels. Mine actually started to fail at a track event but I already had the new pump waiting at home so it wasn't a big deal. You can find these pumps used for about $100 however I bought mine new. The lowest price I could find was at www.partznet.com for $180 but got quotes as high as $250. I also bought the little mesh bag that goes over the pickup. It's angle is slightly better, which helps reduce fuel starvation during fuel slosh in hard left turns. It was part number 2321746110.
Ignition: There are a lot of misconceptions here so read carefully. I have done my research in this area. Lets start with upgraded ignition like the ones offered by Crane and Jacobs. Do not buy these units. They offer no improvement over stock. Many racers use the stock system for their cars with huge hp levels. I have also seen these systems cause problems that led to burned up turbos. Even newr units that have come to market like AEM have serious problems such as over heating and turning off. If you must get a system the only real choice is the HKS Twin Power unit. It's additional performance is questionable but it is a quality unit. It is mostly proven to deliver consistent power under higher boost levels.
Next is plug wires. One popular brand to avoid is Magnecor. They sell based on brand recognition, just like Fram filters, which should also be avoided. These wires have higher resistance with higher levels of EM interference that can mess with your radio and computer. 10 mm Magnecor wires in particular cause problems for many owners. I'm not entirely sure why because many people report positive results so it might be a problem with the boots sealing properly. Jacobs wires also have a flaw which is that their boots can come off of the plug. I bought a set of Accel wires, which served me well for many miles. Taylor is another great brand that many owners use with success. I recently bought a set of MSD wires because it looked like they had superior quality however I was disappointed to see that fitment was a huge issue and that the advertised "separate conductor crimp tabs" was completely false advertising! Most drivers seem to be sticking with stock NGK wires. They have greater resistance but then again resistance is mostly a selling ploy and does not make a plug wire good or bad. One other popular choice are the wires sold by Racing Beat. I have been unable to find any data on these wires but doubt that at their $100 price they are worth buying.
Lastly and most importantly is the plug. I am conducting extensive research on this component which can be seen here.
929 Master Cylinder: This is the device that forces brake fluid to the pistons and stops the car. The Master Cylinder (MC) from the Mazda 929 is slightly larger at 1" instead of the stock 15/16th. Slight modifications are required, which I trusted to KD Rotary. (I hate fluids.) However it should be easy for most people with the right tools. For a complete description go here. http://www.negative-camber.org/crispyrx7/929.htm This is the prefered upgrade if you move to a big brake kit but even with stock brakes it creates a firmer pedal feel. I have stock brakes but when I saw one of these brand new on eBay for about $45 I jumped on it. My stock one was getting old anyway. Well don't expect to repeat my luck as these normally sell for over $100.
Dual Oil Coolers: About 30% of the Rx-7's cooling is performed by the oil system and with a track driven car cooling becomes critical. My car was not an R1 that comes with dual coolers from the factory so I figured it was time to upgrade. Before doing so I installed an oil temp gauge so I could see the difference. Wow, my temps were hot hot HOT. I won't quote them because depending on where you mount your sender unit your temps will vary a lot. Anyway after installing the coolers my temps dropped big time. So which kit did I choose? Well I looked at several including the now unattainable Crooked Willow kit to a GReedy kit from Japan. I went with a slightly more expensive kit though and got the Rotary Extreme kit. I saw several advantages in this kit including how the hoses from the coolers exit from the top of the coolers instead of the bottom as well as the owner's (Chuck) high standards for quality. This kit uses top notch hoses and doesn't have the reported problems with the thermostat that the CW kit did. I'm sure I will be happy with this kit. It could use some ducts though. You may also wish to check out Gotham Racing's new kit.
What's Next?: Lets just say I have a lot of parts sitting around including a vented hood and 99 spec lip.
Update on Sway bars>That darn RB rear bar continued to give me problems so I eventually sold it in favor of a MS one. Talk about impossible to find. I eventually bought one from yahoo auctions Japan through a 3rd party. Now my car is finally the way I like it, just a bit of understeer in the softest position in the rear bar and middle on the front.
Well anyway that is mostly just general junk. I'll start posting some of my better stuff a bit later where I actually talk about a specific component in a more how-to format.
Last edited by GoodfellaFD3S; 11-24-11 at 09:33 PM.
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11-22-11, 11:44 AM
#8
www.silverbulletrx7.com
Thread Starter
Custom Intake
A lot of people poke fun at me when they see my intake and say it is like coffee cans and stuff. Oh well, I still like my design however I would like to someday try my hand at a custom fiberglass over foam mold for the filter and RB ducting.
Intro: Intakes intakes intakes... there are so many to choose from. Some of the more popular ones are CWC and M2's cold air boxes. These draw air from a duct the runs straight down from the box and draws air from next to the radiator. Without question a great design but at a price and sometimes fitment is questionable. The advantages are clear however. Cold air that doesn't rob the intercooler of air because unlike the stock design it doesn't connect to the intercooler's duct. Another advantage to these boxes is the size because it allows for larger intercoolers. The other popular design is basically just cone filters stuck to the end of the two intake hoses. Nothing like sucking hot air from the engine bay right after it passes through the radiator. But hey, you can always come up with some inexpensive heat shielding however even the best shielding will allow hot air to be sucked in. And there are others like the PFS box (outdated) and the Pettit intake (umm yea). For a long time I used a basic Racing Beat intake duct along with the stock box and a K&N filter. A very adequate design but it robed the intercooler or air, was bulky, used the crappy accordion rubber hoses and blocked the radiators air flow. A good intake was therefore on my list but nothing ever really cried out to me so I decided the bolt-on designs just weren't for me. The solution? Build my own from scratch and we aren't talking drilling some holes in the bottom of the stock box or coming up with some Home Depot special. This intake is serious business!
Design Concept: There are several unique design elements incorporated in to my design. To start with it is a cold air system but does NOT use a box like other cold air systems. (Many other cars don't use boxes for cold air systems but since the Rx-7 essentially has two intake tracks a box is almost always used.) Both the primary and secondary turbo intake tracks have separate, fully enclosed, intakes. The primary turbo's (towards the front) intake draws air from beside the radiator much like the M2 style boxes. However these boxes draw air from the main opening in the nose, which feeds the radiator. Since the duct terminates next to the radiator it is possible for air to be sucked from the engine bay, down through the radiator and up in to the intake at idle. My car has a custom under tray that separates the intake from the main opening. It sucks air from under the car. The second turbo's (further back) intake shares the opening with the intercooler just like the stock box does. However due to the fact that this is the second turbo there is no chance of air being sucked from the engine bar, through the intercooler and in to the intake at idle because the turbo only operates at speed. Air is only robbed from the intercooler when the second turbo is activated at around 4500 RPM. The air pump is also plumbed in to this intake section. The air pump operates at below about 3000 RPM so it doesn't effect the intake while operating. It was important to deliver cold air to the air pump because hot air can damage the pump, or so I have heard. Both intakes use mandrel bent stainless pipe, which offers an advantage over the accordion hoses that create turbulent air. Lastly, since there is no box the radiator has an unobstructed path for air flow.
Materials: Adding up the money spent on buying the required materials along with the time spent finding them and designing/building the intake basically brings me to the conclusion that I didn't save any money with this project. Saving money really wasn't what this was about though. Below is a list of the materials I bought along with price and source.
Item Source $
Accell Kool Blue Cone Filter KUD6502-3 Accel *
K&N Cone Filter RU-1770 AJ USA 26.95
K&N Vent Filter 62-1030 AJ USA 18.97
Stainless Steel Mandrel Bent Pipe J Burns Stainless 58.55
1 foot of 2.5" Silicone Hose Baker Precision 25.50
4 feet GoodRidge 3/4" Hose 536-12 Fastway Racing Products 25.57
1 foot Stainless 3/4" pipe Scrap Yard 1.00
Sheet Metal Home Depot 6.00
Screws, clamps, rivets, fiberglass, paint... 15.00
Total 177.54
* This Kool Blue filter was sent to me free of charge from Accell customer service. I had trouble with a stock replacement filter I bought for my Mx-3 and was dealing with them directly. The filter took a long time to get and was not a correct fit. Kool Blue corrected this problem by creating a new filter design for the Mx-3 and sending me the very first one. When I asked about the cone filter they also sent that to me for free. Their customer service impressed me beyond any other company I have ever dealt with. This filter is worth about $50.00 and the quality is very impressive.
Construction: Not including design time this intake probably took around 30 hours to fabricate, maybe more. From conception to completion this took over two years. What follows is a detailed explanation of the construction process with a few more notes about design.
Primary turbo's filter: This involved one bend up and another forward. Due to limitations with mandrel bending of pipe the first bend is not tight enough so I had to put the silicone hose on at a slight angle, which wasn't a problem because at 2.5" in diameter it is slightly larger (and thus lose) than the turbo inlet. Since I knew I would be cutting it close with how much mandrel bent material I had with one J bend I got a filter with a 20 deg outlet. This not only saved me a little material but also offered a slight adjustment margin because I can rotate the filter on the pipe and get different fitment.
Secondary turbo's filter: As you can see by the picture this pipe is much longer and has a good many bends. First it had to take a slight bend down and to the right to clear the strut bar. Next it takes a long straight path to a S bend to arrive at the filter. Tolerances are tight and there is minor rubbing against the air pump's pulley under hard right hand cornering. I with correct this by heating up the pipe and pushing it in about 1/4 of an inch at the rubbing location. The pipe is held in place by not only the turbo and ducting but also a bracket attached to the chassis. This bracket might be the cause of my issues with rubbing but I feel it is a good addition. Both pipes will be receiving a coat of high temperature ceramic clear coat paint. The stainless pipe is rusting a bit so the paint will not only protect the finish but also block a bit of heat. After my friend helped me weld the segments of pipe together I was left with less than 2" of leftover pipe.
Air Pump: This was perhaps the most tricky part. After welding the bung to the intake pipe that was meant for the air pump hose I discovered that the pipe on the pump itself was not a standard size. Instead of 3/4" or 1" it was 7/8". The GoodRidge hose wouldn't fit on the 7/8" pipe no matter how hard I tried. So I gritted my teeth and fabricated a new part for the pump. After screwing up once I succeeded and it's actually pretty cool.
Vent filter: As you can see one hose has a small vent filter on it instead of being plumbed in to the rest of the intake. I have seen other designs where it is but since nobody I asked knew what it was I decided it best to keep it separate because that is how it is on the stock air box. It enters the stock box on the upper right corner where it is isolated with a small subsection of the air box, which contains a foam filter. The exit/entry point is on the side of the box where a plastic pipe is attached that wraps under the box to where it sits open.
BOV: Upgrading the blow off valve (BOV) is a popular upgrade but in comparisons the stock BOV on this car is of exceptional quality. It also offers the ability to plumb the released boost pressure back in to the intake track to help the keep turbos spooled. (Oh darn, I don't have the rice boy whistle sound between shifts.) The BOV can also suck air in to the engine under certain conditions so I believe it is important to filter the air regardless. I plumbed the BOV in to the primary turbo's intake pipe.
CRV: The charge release valve (CRV) is used in the sequential turbo system's pre-spool process and was plumbed in to the secondary turbo's intake pipe.
Primary turbo's ducting: This filter is a perfect cylinder so I calculated the area of the 2.5" pipe and determined the size of the shield I needed to allow that same area around the filter. So basically the filter "can" is big enough so as to not restrict flow around and in to the filter. At the bottom of the can is a rectangular opening that was again designed to maintain at least the same area of the pipe. The back of the can is riveted in to place and sealed with silicone. The filer back is pressed against the opening that I cut in to it for a tight seal. The front is attached by 4 screws so that I can easily remove it for filter removal and cleaning. The entire duct is held in place by 2 bolts that attach to the chassis on the left side.
Secondary turbo's ducting: The Kool Blue filter is not a perfect cylinder and is instead tapered with a second smaller filtration element at the top. The heat shield on this filter is flush against the widest part of the filter and because of the taper opens up towards the filter's top. I again calculated the area of this "ring" to make sure it's area was at least that of the 2.5" pipe. The heat shield is open on both ends and is held on a round shape with two folds at the bottom that lock together. Instead of fabricating an entire duct to attach to the intercooler duct I hacked the Racing Beat duct to pieces are shortened it. It is held in place by a aluminum bracket. I then connected the two with a fiberglass thing. I say thing because I didn't do a great job. I honestly didn't know how to create the custom shape out of fiberglass and have it turn out nice and smooth. Instead it is functional only. It is attached with screws. The filter is accessible by first removing the fiberglass duct and then the heat shield. All of the shielding for both filters will be painted with ceramic paint to help keep heat out eventually.
Conclusion: The results are awesome. The pipes remain cool, which proves that this is a cold air intake and the performance is surely enhanced. (Ok so I don't have proof.) It is a unique part in a different car, not just another bolt-on attached to a Honda Civic. Some people like to think their car's are customized but really they are just a number of different parts from different manufactures. It's not until you actually do something that can't be easily duplicated that you truly have a customized car.
Intro: Intakes intakes intakes... there are so many to choose from. Some of the more popular ones are CWC and M2's cold air boxes. These draw air from a duct the runs straight down from the box and draws air from next to the radiator. Without question a great design but at a price and sometimes fitment is questionable. The advantages are clear however. Cold air that doesn't rob the intercooler of air because unlike the stock design it doesn't connect to the intercooler's duct. Another advantage to these boxes is the size because it allows for larger intercoolers. The other popular design is basically just cone filters stuck to the end of the two intake hoses. Nothing like sucking hot air from the engine bay right after it passes through the radiator. But hey, you can always come up with some inexpensive heat shielding however even the best shielding will allow hot air to be sucked in. And there are others like the PFS box (outdated) and the Pettit intake (umm yea). For a long time I used a basic Racing Beat intake duct along with the stock box and a K&N filter. A very adequate design but it robed the intercooler or air, was bulky, used the crappy accordion rubber hoses and blocked the radiators air flow. A good intake was therefore on my list but nothing ever really cried out to me so I decided the bolt-on designs just weren't for me. The solution? Build my own from scratch and we aren't talking drilling some holes in the bottom of the stock box or coming up with some Home Depot special. This intake is serious business!
Design Concept: There are several unique design elements incorporated in to my design. To start with it is a cold air system but does NOT use a box like other cold air systems. (Many other cars don't use boxes for cold air systems but since the Rx-7 essentially has two intake tracks a box is almost always used.) Both the primary and secondary turbo intake tracks have separate, fully enclosed, intakes. The primary turbo's (towards the front) intake draws air from beside the radiator much like the M2 style boxes. However these boxes draw air from the main opening in the nose, which feeds the radiator. Since the duct terminates next to the radiator it is possible for air to be sucked from the engine bay, down through the radiator and up in to the intake at idle. My car has a custom under tray that separates the intake from the main opening. It sucks air from under the car. The second turbo's (further back) intake shares the opening with the intercooler just like the stock box does. However due to the fact that this is the second turbo there is no chance of air being sucked from the engine bar, through the intercooler and in to the intake at idle because the turbo only operates at speed. Air is only robbed from the intercooler when the second turbo is activated at around 4500 RPM. The air pump is also plumbed in to this intake section. The air pump operates at below about 3000 RPM so it doesn't effect the intake while operating. It was important to deliver cold air to the air pump because hot air can damage the pump, or so I have heard. Both intakes use mandrel bent stainless pipe, which offers an advantage over the accordion hoses that create turbulent air. Lastly, since there is no box the radiator has an unobstructed path for air flow.
Materials: Adding up the money spent on buying the required materials along with the time spent finding them and designing/building the intake basically brings me to the conclusion that I didn't save any money with this project. Saving money really wasn't what this was about though. Below is a list of the materials I bought along with price and source.
Item Source $
Accell Kool Blue Cone Filter KUD6502-3 Accel *
K&N Cone Filter RU-1770 AJ USA 26.95
K&N Vent Filter 62-1030 AJ USA 18.97
Stainless Steel Mandrel Bent Pipe J Burns Stainless 58.55
1 foot of 2.5" Silicone Hose Baker Precision 25.50
4 feet GoodRidge 3/4" Hose 536-12 Fastway Racing Products 25.57
1 foot Stainless 3/4" pipe Scrap Yard 1.00
Sheet Metal Home Depot 6.00
Screws, clamps, rivets, fiberglass, paint... 15.00
Total 177.54
* This Kool Blue filter was sent to me free of charge from Accell customer service. I had trouble with a stock replacement filter I bought for my Mx-3 and was dealing with them directly. The filter took a long time to get and was not a correct fit. Kool Blue corrected this problem by creating a new filter design for the Mx-3 and sending me the very first one. When I asked about the cone filter they also sent that to me for free. Their customer service impressed me beyond any other company I have ever dealt with. This filter is worth about $50.00 and the quality is very impressive.
Construction: Not including design time this intake probably took around 30 hours to fabricate, maybe more. From conception to completion this took over two years. What follows is a detailed explanation of the construction process with a few more notes about design.
Primary turbo's filter: This involved one bend up and another forward. Due to limitations with mandrel bending of pipe the first bend is not tight enough so I had to put the silicone hose on at a slight angle, which wasn't a problem because at 2.5" in diameter it is slightly larger (and thus lose) than the turbo inlet. Since I knew I would be cutting it close with how much mandrel bent material I had with one J bend I got a filter with a 20 deg outlet. This not only saved me a little material but also offered a slight adjustment margin because I can rotate the filter on the pipe and get different fitment.
Secondary turbo's filter: As you can see by the picture this pipe is much longer and has a good many bends. First it had to take a slight bend down and to the right to clear the strut bar. Next it takes a long straight path to a S bend to arrive at the filter. Tolerances are tight and there is minor rubbing against the air pump's pulley under hard right hand cornering. I with correct this by heating up the pipe and pushing it in about 1/4 of an inch at the rubbing location. The pipe is held in place by not only the turbo and ducting but also a bracket attached to the chassis. This bracket might be the cause of my issues with rubbing but I feel it is a good addition. Both pipes will be receiving a coat of high temperature ceramic clear coat paint. The stainless pipe is rusting a bit so the paint will not only protect the finish but also block a bit of heat. After my friend helped me weld the segments of pipe together I was left with less than 2" of leftover pipe.
Air Pump: This was perhaps the most tricky part. After welding the bung to the intake pipe that was meant for the air pump hose I discovered that the pipe on the pump itself was not a standard size. Instead of 3/4" or 1" it was 7/8". The GoodRidge hose wouldn't fit on the 7/8" pipe no matter how hard I tried. So I gritted my teeth and fabricated a new part for the pump. After screwing up once I succeeded and it's actually pretty cool.
Vent filter: As you can see one hose has a small vent filter on it instead of being plumbed in to the rest of the intake. I have seen other designs where it is but since nobody I asked knew what it was I decided it best to keep it separate because that is how it is on the stock air box. It enters the stock box on the upper right corner where it is isolated with a small subsection of the air box, which contains a foam filter. The exit/entry point is on the side of the box where a plastic pipe is attached that wraps under the box to where it sits open.
BOV: Upgrading the blow off valve (BOV) is a popular upgrade but in comparisons the stock BOV on this car is of exceptional quality. It also offers the ability to plumb the released boost pressure back in to the intake track to help the keep turbos spooled. (Oh darn, I don't have the rice boy whistle sound between shifts.) The BOV can also suck air in to the engine under certain conditions so I believe it is important to filter the air regardless. I plumbed the BOV in to the primary turbo's intake pipe.
CRV: The charge release valve (CRV) is used in the sequential turbo system's pre-spool process and was plumbed in to the secondary turbo's intake pipe.
Primary turbo's ducting: This filter is a perfect cylinder so I calculated the area of the 2.5" pipe and determined the size of the shield I needed to allow that same area around the filter. So basically the filter "can" is big enough so as to not restrict flow around and in to the filter. At the bottom of the can is a rectangular opening that was again designed to maintain at least the same area of the pipe. The back of the can is riveted in to place and sealed with silicone. The filer back is pressed against the opening that I cut in to it for a tight seal. The front is attached by 4 screws so that I can easily remove it for filter removal and cleaning. The entire duct is held in place by 2 bolts that attach to the chassis on the left side.
Secondary turbo's ducting: The Kool Blue filter is not a perfect cylinder and is instead tapered with a second smaller filtration element at the top. The heat shield on this filter is flush against the widest part of the filter and because of the taper opens up towards the filter's top. I again calculated the area of this "ring" to make sure it's area was at least that of the 2.5" pipe. The heat shield is open on both ends and is held on a round shape with two folds at the bottom that lock together. Instead of fabricating an entire duct to attach to the intercooler duct I hacked the Racing Beat duct to pieces are shortened it. It is held in place by a aluminum bracket. I then connected the two with a fiberglass thing. I say thing because I didn't do a great job. I honestly didn't know how to create the custom shape out of fiberglass and have it turn out nice and smooth. Instead it is functional only. It is attached with screws. The filter is accessible by first removing the fiberglass duct and then the heat shield. All of the shielding for both filters will be painted with ceramic paint to help keep heat out eventually.
Conclusion: The results are awesome. The pipes remain cool, which proves that this is a cold air intake and the performance is surely enhanced. (Ok so I don't have proof.) It is a unique part in a different car, not just another bolt-on attached to a Honda Civic. Some people like to think their car's are customized but really they are just a number of different parts from different manufactures. It's not until you actually do something that can't be easily duplicated that you truly have a customized car.
Last edited by GoodfellaFD3S; 11-24-11 at 09:35 PM.
11-22-11, 03:41 PM
#10
Original Gangster/Rotary!
iTrader: (213)
Thanks for posting Charles 
I too remember your site from way back in the day when I was new to the RX-7
I went through and added spacing to your paragraphs to make them easier to read.... I'll see about moving this to another more appropriate section in a bit.
I too remember your site from way back in the day when I was new to the RX-7
I went through and added spacing to your paragraphs to make them easier to read.... I'll see about moving this to another more appropriate section in a bit.
11-27-11, 11:10 AM
#15
www.silverbulletrx7.com
Thread Starter
Intro: Ahhh custom... I do so love making things myself. Some people call their cars custom just because they put different parts on it but a truly custom car has hand fabricated parts on it that no other car has. I suppose my cat-back is almost a Frankenstein mishmash of parts that might not look pretty but it is functional and is better than most exhausts that can be purchased. If you are interested in how and why I did it then read on.
In the Past: Naturally every car comes with a stock exhaust and in the case of the Rx-7 it is a 2.5" mild steel unit. I am convinced that car manufactures have a secret deal with muffler shops so that they won't spend a few extra dollars to make exhausts out of stainless. Anyway when I bought my car I was given the old stock exhaust, which was in fine working order. However, installed on my car was an old mild steel 3" system produced by GReddy. I actually really liked this exhaust. I guess small changes over time aren't as noticeable as catastrophic failures so as the top of my muffler rusted away I didn't notice. However one day after a race event I noticed erratic changes in tone to my car's sound. I also thought my car seemed to be getting louder over the years because I remembered a time when the sound didn't annoy me so much. I thought maybe I was becoming a sissy. Either that or I had a problem with my car so I attributed it to a blown exhaust gasket. I took my car to KD Rotary to have it checked out. Initially they agreed it was an exhaust gasket but later found that only the downpipe gasket was blown. They also informed me that my muffler had a hole in it big enough to fit your hand in to. I inspect my car regularly but missed this hole because it was on the top of the muffler instead of the bottom where I would expect to find more rust. Now that I think back I was finding random chunks of fiberglass in odd places back there that were being blown out of the ever enlarging hole. I was planning on replacing the GReddy with a custom unit in a year or two anyway so this just accelerated the project and pushed back my lingering vented hood project.
Materials: The design for a cat-back exhaust is rather simple. 3" pipe is the only acceptable choice for the 3rd gen Rx-7 except under extreme circumstances. Naturally it should be all stainless with a muffler that can withstand the heat from a rotary. I found that Magnaflow had a good reputation for this and their website's info on how they are constructed convinced me it was the right choice. They also have a wide array of sizes and a lifetime warranty. I decided on a twin tip system because of appearance and that a dual tip system can be quieter. It is more restrictive though. I went with 2 1/4" inch tips, whose combined area is greater than a single 3" tip. It took me a lot of time to pick a set of tips that I liked. I eventually decided on a double walled angle cut polished tip. Honestly I ended up with pretty much the most expensive tips out there that I came across. They are "hand crafted" polished stainless tips from Thermal R&D. Most stainless systems come with a mild steel exhaust flange for some reason but I found a stainless one from Racing Beat. For simplicity I reused the hangers from my old GReddy. Here is a list of my parts and the vendors I found with the best prices. (Prices include shipping)
Item Manufacture Part # Vendor $
Muffler Magnaflow 14278 www.performancepeddler.com 93.40
Pipe ? www.performance-curve.com 45.96
Flange Racing Beat 16185 www.racingbeat.com 22.57
Tips Thermal R&D 3246A www.kidimports.com 53.10 x 2
Construction: Just as with anything custom, construction is difficult and time consuming. I started out with two examples of exhaust systems that fit, so I used the curves as a template. Every detail was measured and considered because I couldn't fabricate the system one curve at a time with the muffler attached to my car while on a lift. Wouldn't that be nice to just put the parts on, consider an angle and then start welding? Oh well, if I was that rich I'd probably be spending my time making custom cars, not custom exhausts. So anyway I cut the pipe and laid it out as I thought would be best. I then used masking tape to hold it together for a test fit under my car. Once satisfied I took the parts to my friend's shop who owns a welding machine. A few minutes later and I had some parts together. I wasn't comfortable doing it all at once so I made several trips after additional test fittings. The angle of the flange was particularly difficult and took some modifications. The hangers also needed modified. Only the tips were easy and were angled slightly to the left to lineup with the car better.
Conclusion: I don't have any dyno charts for this cat-back but I have no reason to believe I introduced any restrictions in flow, unless that massive hole was producing horsepower. The appearance is great and is such an improvement over the boring single walled tip on my old GReddy. The sound is stellar. It is so quiet compared to a broken muffler that I can actually hear myself think. Now that is not all together a good thing considering the things I think about. Anyway it is a deep throaty sound that almost hides the menacing power that would turn any normal car's driveshaft in to a Twizzler.
Update>I get tons of complements on the sound my car makes after adding this exhaust.
In the Past: Naturally every car comes with a stock exhaust and in the case of the Rx-7 it is a 2.5" mild steel unit. I am convinced that car manufactures have a secret deal with muffler shops so that they won't spend a few extra dollars to make exhausts out of stainless. Anyway when I bought my car I was given the old stock exhaust, which was in fine working order. However, installed on my car was an old mild steel 3" system produced by GReddy. I actually really liked this exhaust. I guess small changes over time aren't as noticeable as catastrophic failures so as the top of my muffler rusted away I didn't notice. However one day after a race event I noticed erratic changes in tone to my car's sound. I also thought my car seemed to be getting louder over the years because I remembered a time when the sound didn't annoy me so much. I thought maybe I was becoming a sissy. Either that or I had a problem with my car so I attributed it to a blown exhaust gasket. I took my car to KD Rotary to have it checked out. Initially they agreed it was an exhaust gasket but later found that only the downpipe gasket was blown. They also informed me that my muffler had a hole in it big enough to fit your hand in to. I inspect my car regularly but missed this hole because it was on the top of the muffler instead of the bottom where I would expect to find more rust. Now that I think back I was finding random chunks of fiberglass in odd places back there that were being blown out of the ever enlarging hole. I was planning on replacing the GReddy with a custom unit in a year or two anyway so this just accelerated the project and pushed back my lingering vented hood project.
Materials: The design for a cat-back exhaust is rather simple. 3" pipe is the only acceptable choice for the 3rd gen Rx-7 except under extreme circumstances. Naturally it should be all stainless with a muffler that can withstand the heat from a rotary. I found that Magnaflow had a good reputation for this and their website's info on how they are constructed convinced me it was the right choice. They also have a wide array of sizes and a lifetime warranty. I decided on a twin tip system because of appearance and that a dual tip system can be quieter. It is more restrictive though. I went with 2 1/4" inch tips, whose combined area is greater than a single 3" tip. It took me a lot of time to pick a set of tips that I liked. I eventually decided on a double walled angle cut polished tip. Honestly I ended up with pretty much the most expensive tips out there that I came across. They are "hand crafted" polished stainless tips from Thermal R&D. Most stainless systems come with a mild steel exhaust flange for some reason but I found a stainless one from Racing Beat. For simplicity I reused the hangers from my old GReddy. Here is a list of my parts and the vendors I found with the best prices. (Prices include shipping)
Item Manufacture Part # Vendor $
Muffler Magnaflow 14278 www.performancepeddler.com 93.40
Pipe ? www.performance-curve.com 45.96
Flange Racing Beat 16185 www.racingbeat.com 22.57
Tips Thermal R&D 3246A www.kidimports.com 53.10 x 2
Construction: Just as with anything custom, construction is difficult and time consuming. I started out with two examples of exhaust systems that fit, so I used the curves as a template. Every detail was measured and considered because I couldn't fabricate the system one curve at a time with the muffler attached to my car while on a lift. Wouldn't that be nice to just put the parts on, consider an angle and then start welding? Oh well, if I was that rich I'd probably be spending my time making custom cars, not custom exhausts. So anyway I cut the pipe and laid it out as I thought would be best. I then used masking tape to hold it together for a test fit under my car. Once satisfied I took the parts to my friend's shop who owns a welding machine. A few minutes later and I had some parts together. I wasn't comfortable doing it all at once so I made several trips after additional test fittings. The angle of the flange was particularly difficult and took some modifications. The hangers also needed modified. Only the tips were easy and were angled slightly to the left to lineup with the car better.
Conclusion: I don't have any dyno charts for this cat-back but I have no reason to believe I introduced any restrictions in flow, unless that massive hole was producing horsepower. The appearance is great and is such an improvement over the boring single walled tip on my old GReddy. The sound is stellar. It is so quiet compared to a broken muffler that I can actually hear myself think. Now that is not all together a good thing considering the things I think about. Anyway it is a deep throaty sound that almost hides the menacing power that would turn any normal car's driveshaft in to a Twizzler.
Update>I get tons of complements on the sound my car makes after adding this exhaust.
