Mod list to keep your FD running happy
 

Ok, here is my "Mod list to keep your FD running happy:"

(this assumes semi-emissions legal [main cat on] and near-stock boost levels [no more than 12])

Boost gauge

turbo timer

Water temp gauge

Fan mod

Silicone hose/zip tie job

aluminum AST

catback

downpipe

NGK Plat. 9's all around/plug wires

Power FC

Intake

Aluminum Radiator

Intercooler

Battery to the hatch/storage bins

Synthetic in the tranny

When replacing the clutch, get a lightweight flywheel

If you're on a budget starting off, you don't need a BOV, don't need crazy rims, don't need a body kit or spoiler

change your oil every 2000 miles, check it at every gas fillup, let the car warm up before revving over 4k, always use 93 octane, if you see the temps get over 105 C take preventative measures immediately, pop the hood whenever feasible to get the heat out of the engine bay, whenever possible park to minimize door dings, change your plugs every 8-10k miles, check the coolant level at the radiator neck every few weeks, the list goes on and on...

I'm just typing off the top of my head here guys; feel free to correct me or chime in...

if you're gonna go nuts how bout a vented hood? can't get enough cooling ya know.

that list looks like more than mods to keep your car happy. that should be good for ...what? 300ish to the wheels at stock or near stock boost?

that list is kinda what i'm going for except i went with hi flo cat instead of main.

question- when do you NEED an upgraded bov? exactly what does that help?

you NEED it when you wanna hear "Psssssssssssssst".

it helps you make that noise and look cool to all of your buddies who drive hondas

Replace all the cooling system hoses. The ones on the turbos get brittle and fail with no warning, dumping out all your coolant. This is a common one which is never listed.

Next one is upgrade to the R1 second oil cooler (if you don't have one). One oiler cooler on a base or touring with the horsepower bumped up (or hard driving) will run the oil hot.

Fix your engine grounds.

Check that both cooling fans work. With age, it is common for 1 to fail without you noticing.

I find that you should change the plugs every 6 months under hard driving. The electrodes wear out quickly.

this is a very nice post for people who need to know how to keep an RX-7 safe... I would higly recommend this list to anyone.

1FAST7

PFC
 

Nice list...but i noticed you have the Power FC on their. What happens when you dont know how to tune a PFC? then what would you suggest as a alternate ECU? Also what do you need to know about cars to be able to properly tune/operate a PFC? thanks.

Re: PFC
 

I'd be interested to know the answer to that too. I gather that the PFC will produce slightly more HP, and perhaps smother running, but needs to be proffesionally tuned on a dyno. Other than that, I don't think I'd ever personally need the commander! I've also heard of a few engines being blown while tuning with a PFC.

PFC needing to be tuned on a dyno . . .
 

You can say this all you want but I'm finding more and more that the base maps for intake, dp, and cb are very same and very good. Once you add the intercooler then you should add some more fuel, but it can be done somewhat easily and safely. Silverseven and I are tuning his car right now and we the base maps plus fuel added in the PIM and we are seeing good results without adding too much fuel. More to come as tuning continues ..... so don't ask for more info (yet) because we don't have final tuning complete.

My point being for people who are simply looking for slightly more power, a smoother running car and some tuning capabilites the PowerFC is the best option period. Heck is you aren't going to mod the car don't buy the commander and that will save $$ .... or buy it in a group deal to save money.

Oh yeah, battery to the hatch isn't really that necessary .... there are many alternatives to that. Not saying that is a bad thing at all, just doesn't have to be done. Hose job...don't do it till something goes. There are a handful of must change lines, but those aren't even under the manifold. I've seen too many people who pull apart their rats nest for this job and then put it back to gether wrong and anyone who has done this job knows those hoses are so brittle and hard they aren't going anywhere. Take your pick on the AST or elimination kit. I've had both and I didn't notice any difference. Also consider converting your stock coolant temp gauge to a linear gauge ... saves $$ and keeps you from adding a gauge in your interior.

the power FC doesn not need to be tuned, untuned it it like having a pettit ecu or M2. But hte comander, etc and start to really get some power.

I agree with most everything, Goodfellas said except for all those gauges. In my opinion you don;t need that shit if you have a commander becasue eit tells you everything. right there. Althgough I woudl get boost gauge because easier to look at.

I would also disagree with radiator. Maybe needed in Texas, but I am in georgia and have no problems, except runing to cool. TH PFC will make fans come on much earlier which makes the fan mod a complete waste of time.With PFC they will come on were normally someone woudl set with fan mod. I wouldn;t relocate battery unless you had to. I also wouldn't put a turbo timer, I thjink it is pretty much a waste of cash, modern turbochargers are very well cooled, and just driving slowly and letting it sit for 30 seconds is usually good enough.(read that on some site)

Saying that, everyone has opinions on what is needed, I know goodfellas is building quite the beastly 7 and he knows what he is talking about. I just like to save cash unless it is really needed, or I think the benefit will outway the cost.


The most important thing is PFC, PFC and another PFC. if you mod your car past inatke and dp,and CB buy it period.

Hi KZ1,

Good points all man, I agree with alot of what you said but must respectfully disagree w/a few points :). Allow me to clarify...

re: the gauges, it's a matter of preference. I have my commander mounted w/velcro right near the red hazard button and refer to that for Boost, Inj Duty, Intake air temp, and Water temp. Some like the gauges on the A-pillar because you don't have to take your eyes off the road. But you're right; to save cash, get the FC and commander and you're set.

re: the radiator, must disagree w/you dude :). Chris at RP (who knows a thing or two ;)) told me that w/the stock rad, it's not a question of if it'll die, but *when* it'll die. Granted, it gets hot as hell here in TX, but it gets hot in the NJ and PA summers too. Seriously, when overheating kills your motor, why fuck around? The stocker is thin, poorly made, and has multiple failure points.

re: the fans, I haven't seen a difference w/my Power FC. The fan mod I'm referring to runs them on high for 10 minutes *after* the rex shuts down.

Relocating the battery to the hatch puts more weight over the rear axle, which equals better traction. Every little bit helps. It also frees up some space under the hood, which helps to circulate air and cool things down.

I think a turbo timer is a necessity. Take your rex out on the highway at night. Get on boost a few times, rev out a few gears. Park the car, pop the hood, and peer in toward the front turbo. It'll be easy to see it because it'll be glowing like a hot coal. The timer lets the oil circulate and cool the turbo down. I tried the "sit in car and wait" method, and that's a load of horseshit :D. Time is money, and more often than not waiting is inconvenient. Spring for the 80 bucks and get one.

Keep the good ideas coming fellas; I want this thread in the archives to point all the newbies to...

Rich
Building a Beast :p

ok, the after sutdown fan mad is cool, I personally wouldn't sepnd the time(my temps never get over 98C), but nice feature. for some reason I thought you refered to the other one.

I never look at my gauges while getting on it anyway, unless I am tuning.

I woudl like to add one. THe best thing you can do to keep your RX7 running healthy is to read through this site. I cannot emphasize that enough, I am sure everyone agress with me. THere is a lot of bullshit but it is far out weighed by good content. As long as you rememebr that some of these mods are propagated by vendors trying to sell products, and that some of rob's robinettes reliability mods are idiotic. you will be fine.

can anyone tell me where I can get a linear temp gauge that is a direct replacement for the stocker? thanks

one more to add to the list:

relocate the fuel filter to the engine bay, use a low pressure drop, washable element, and clean it often....this car flows so much gas and changing the stock one is such a massive PITA that I think relocation of the filter is another "must do" item

I disagree about turbo timers....I think they are dumb....the idea is to get off the gas after a hard run and just operate the car at low throttle for 5-10 minutes before you park it, to get some cool breeze goign through the radiator....I'm my own turbo timer....idling the car for several minutes helps it load up

I'm re-posting Jim Lab's excellent post on 3rd gen reliability issues from the archive here, in case any of you missed it....it is one of the most well written and comprehensive posts on the subject I've seen



First off, do a lot of research before you start tampering with the car, because like a couple posts above, people are full of information... but not necessarily 100% correct information.

12 psi on the stock fuel system with the stock ECU equals one thing... fuel cut. It's not fun, don't do it. 14 psi on the stock fuel system, without ECU modification or an aftermarket computer equals one thing... time for a new engine. You will not get away with that. Most people don't get away with 14 psi anywhere but on the dyno, with race fuel, and ice on the motor. Forget about anything but stock boost until you've provided extra fuel.

That said, there have been people (since you asked about maximum boost pressure on the stock motor) who have run above 30 psi, and I know for a fact that the Ianetti 3mm ceramic apex seals have been run at 45+ psi. Boost doesn't kill the motor, inadequate fuel does. Detonate at 10 psi and you'll blow the motor, regardless of the fact that it's "only" stock boost. Even with ceramic apex seals, detonation will still take your motor out.

So first off, start with the reliability mods.

1) Check and find out if the car has had all TSBs (technical service bulletin) performed. If it hasn't get them done. Engine fires were more common than one might like from problems with the fuel lines, and there were recalls to repair these problems on the earlier cars, especially 1993 models. Your local Mazda dealership should be able to help you find out this information.

2) Get a boost gauge. In fact, before you buy the car, if you can rig up a temporary mechanical boost gauge (and thread the rubber hose out through a gap in the hood at the windshield) and find out what the stock boost levels are, you should do it. If you're not seeing (approximately) 10-8-10, the 8 indicating a drop in boost level as the second turbo is brought online at around 4,500 rpm, then you've got problems before you've even started. Get a boost gauge so you can diagnose boost problems.

3) Get a downpipe, ceramic coated if possible. Get the pre-cat out of the car, and if the main catalytic converter is suspect, replace it so that you don't have excessive backpressure and heat in the exhaust system. The pre-cat warms the enigne more quickly, but does little more than create heat. It can and will (if it has not already done so) bake all the vacuum lines controlling the sequential turbo system, making them brittle or prone to cracking. This is where a large number of boost response problems can come from. Get the heat out of the engine bay, because the pre-cat can (and again, does) bake your battery too, quickly killing most underhood batteries from the excessive heat. There have been several instances of batteries exploding.

4) Get an aftermarket radiator. These cars tend to overheat with extended heavy driving, and the stock cooling system is inadequate, especially for hotter climates. Get a Fluidyne (or other) replacement radiator and improve your chances of keeping the engine alive. Overheating is probably the second most common cause of engine replacement, shortly following detonation.

5) Closely monitor your water temp, but not with the stock gauge. The stock water temp gauge is weighted towards the center of its range. Therefore, by the time it starts moving to the high end, it's probably already too late. Get a "real" water temperature gauge and keep a close eye on your coolant temperature. If the gauge starts to rise excessively, stop doing what you're doing, and coast the car to let it cool down.

6) Get the stock intercooler out of the car. It's next to worthless, and acts more like a heatsink, sitting directly above the radiator, than an intercooler. Intake temperatures with the stock intercooler at stock boost levels can be very, very high if the car has sat (in traffic, for example) at idle for long periods. At speed, it's not as much of a problem, but it's still inadequate at best. Once you see how tiny the core of the stock IC is, you'll wonder what Mazda was thinking. If you intend to run higher boost levels, you MUST get rid of the stock intercooler. You can either choose between an underhood model (M2 Performance "medium" and "large" ICs, for example), or a front mount model. Keep in mind that a front mount model will not only collect rock damage much quicker, but will block air flow to the radiator also. FMICs are fine for drag racing, but are not the best solution for a street driven car or one that will see track use at extended high boost levels. It may cool the incoming air, but so do the underhood models, and they don't inhibit airflow through the radiator.

7) Once you raise boost, CONTROL it. Buy a *quality* boost controller and limit your boost. As mentioned above, without modification of the stock ECU, you'll hit fuel cut at 12 psi. With a downpipe and an upgraded intercooler, it's almost a given that you'll peak at 12 psi or a bit higher, so you need to control boost to safe levels, and above all, prevent boost spiking or creep. There are several models that people swear by, including the HKS EVC IV, EVC EZ, the Blitz controller, and the A'pexi AVC-R. Get a boost controller and keep your boost at safe levels.

8) While it isn't 100% accurate (since nothing but a multi-wire heated wide-band 02 sensor is truly accurate, but at high cost), you can monitor your oxygen sensor voltage to give you an indication of how rich (or lean) your engine is running. Anything below 0.86 volts is getting very lean, and if your readings are in the 0.82-0.84 volt range, you need to back your boost level off until you get adequate fuel. Anything from 0.80 and lower is almost guarantee to lead to engine replacement. 0.90 and higher is fairly rich. There are many manufacturers of Air/Fuel ratio gauges to monitor this reading, or you can (with a little work) hook up a multimeter to the wire lead at the ECU, which works for temporary measurement.

9) In combination with monitoring Air/Fuel ratio, you should also get a quality EGT (exhaust gas temperature) gauge and monitor that as well. Depending on your mods, people can give you a good idea of the ranges you should be seeing as far as exhaust temperatures and what's relatively safe. As with the coolant temperature, when EGTs start to rise dramatically, it's time to back off and let the car cool down. Which leads us to...

10) More fuel. Probably the most important and most neglected aspect of keeping your rotary healthy. If you're going to run higher than stock boost, you *will* need fuel modifications. The cheapest, a rising rate fuel pressure regulator (often called the "poor man's fuel computer) will raise fuel rail line pressure depending on boost level, and at higher pressures, more fuel is injected at a specific injector duty cycle than at lower pressures.

Speaking of injector duty cycle, the AVC-R boost controller from A'pexi will allow you to monitor the duty cycle of your injectors. Ideally, they should not be running at higher than 85-89% duty cycle. Doing so runs the risk of having them sticking open (creating a very rich situation) or stick closed (creating a very dangerous lean condition). If you're buying a used car, it is not a bad idea to have the stock injectors removed, cleaned and flow matched, or replaced if necessary. Your engine's health can literally depend on the condition of the injectors. If you're seeing duty cycles higher than these levels, it's time for larger injectors.

Which brings us to fuel system mods. The stock lines and pump are adequate for about 12-13 psi, but it is best to be on the safe side. Yes, there are people who run their cars at the track or on the dyno at 14+ psi (with the stock turbos) on the stock fuel lines and injectors, but always with a modified ECU (reprogrammed fuel maps for high boost) or a piggyback fuel computer, and almost always with an upgraded fuel pump and pressure regulator. And almost always with race gas, to increase octane and reduce the chances of detonation. On the street, the chances are very good that your car will not survive extended boost levels around 14-15 psi on the stock fuel system. Some get away with it, many don't.

Upgrade the fuel pump at the very least, and the lines, if possible. Many use the Cosmo (20B rotary) fuel pump, or the MKIV (fourth generation) Supra fuel pumps, which are almost identical. A lot use the Walbro fuel pump which outflows the previous too significantly, and many use the big Bosch pump (there are three models, the one you want has a screened inlet across the entire bottom of the pump, not the ones with a nut fitting for in-line use) to provide adequate fuel. The stock fuel lines are only the equivalent of roughly -4 aftermarket lines, so even upgrading at least your delivery line (there are three... one for fuel delivery, one for fuel return to the fuel tank, and one for the charcoal cannister vapor reclamation system) to a -6 (pronounced "dash 6") line is an improvement. Upgrading the fuel fittings on the tank outlet to aftermarket AN (Army/Navy spec) fittings and -8 fuel line is even better. The more fuel you can deliver, the better. Your return line can be smaller than your delivery line, but it doesn't hurt to upgrade that too, if you're really flowing a lot of fuel.

Upgrade the fuel computer. Probably the cheapest and easiest way is to have the stock computer modified. A piggyback chip is soldered onto the stock ECU motherboard and an EEPROM is "burned" with the fuel maps for your modifications. Many vendors can do this, but among them are Pettit Racing, M2 Performance, and XS Engineering. This is a good "intermediate" solution, but not ideal. The stock computer doesn't handle fuel delivery as effectively as it might, and a piggyback computer (PFS "purple" PFC, for example) or complete aftermarket computer (Motec, Electromotive, Haltech, Wolf3D, etc.) are better solutions, especially if you're going to upgrade to a single turbo, which will require even higher fuel delivery rates. The Power FC computer is also highly recommended.

Upgrade injectors. If you change the size of the stock injectors (as opposed to adding additional injectors on the intake manifold itself or on the intake elbow, as some kits do) and still have the stock computer, will you need to maintain the ratio in size of the injectors. The primary injectors are 550cc injectors and the secondaries are 850cc. Some people have had luck with upgrading the secondaries only, but some have upgraded both to 720cc primaries and 1220 secondaries (roughly maintaining the 1.5-1.6 ratio) and using the Peter Farrell PFC to control fuel delivery. But if you go with an aftermarket system, then it is much easier to control larger injectors and avoid the problems with tuning that changing the ratio between primary and secondary can cause.

11) Make more power? Replace your clutch. Or at least make sure that you have a rev limiter in place should the clutch let go. Get an ACT or Centerforce Dual-Friction clutch (or other aftermarket clutch) and don't even bother with the Mazdacomp 17% stiffer pressure plate or experimenting with friction plates. Buy an entire system and do it right once, the first time. The ACT clutch is highly recommended by many owners. The main problem with the stock clutch is that it's adequate for stock power levels, but can quickly be overcome (even in new, unabused condition) by additional power. Although the rotary engine loves to rev, there is a limit, and without a rev limiter (which can be removed when the ECU is reprogrammed), you need to make sure that you keep the engine from over-revving. Doing so can throw a corner seal or cause other internal damage to the motor, and the apex seals (under boost) tend to float (or pull away from the surface of the rotor housing) at revolutions higher than 8,000 per minute. When this happens, they cannot disperse heat, they can warp, and they can break, causing internal engine damage and damage to the turbo(s) as any broken pieces exit through the exhaust ports.

By adding a Crane HI-6 ignition computer, you can get a hotter spark to the engine, improve fuel economy (in some cases), eliminate the high end missing that some cars experience, and have a fail-safe for high rpm by setting its integrated rev limiter. There are several how-tos on the web for this mod and others.

12) Run spark plugs with a colder heat range. If you're going to run high boost, run NGK BUR9EQP plugs in both the leading and trailing positoins, and it may be necessary to go one heat range lower and run BUR11EQPs. A hotter plug retains more heat, which is exactly what you *don't* want under high boost, because it can lead to pre-ignition of the air/fuel charge before the optimal firing sequence. This cause an uneven burn (detonation), extremely high internal pressures, and will probably break your apex seals, especially with repetition. If you hear sounds under the hood like your engine is trying to make "popcorn", you need to back off immediately, but it'll probably be too late at that point.

Cheap insurance would be to buy the Jacobs knock sensor (more sensitive than the stock knock sensors) which will back out timing at the onset of the detection of detonation or "engine knock". It's not foolproof, but the purchase price is far cheaper than replacing an engine.

So to wrap this up, monitor your systems closely, provide enough fuel for the amount of boost pressure you plan to run, and with proper tuning, you can go a long way towards preventing the unwanted task of replacing your engine. These mods aren't 100% guaranteed to get 100k miles out of an engine, but they go a long way towards improving reliability and longevity. As always, increasing the power output of an engine does reduce its lifespan, and even with the best tuned system in the world, things can (and do) go wrong. There is one person I know who lost an engine at stock boost even with ceramic apex seals and a Motec system tuned by Mandeville Racing. Bad things do happen ocassionally, sometimes without reason.

Just keep an eye on your gauges and spend at least as much on your fuel system as you do on other mods, and you'll go a long way towards preventing anything like that from happening to you. And obviously, the more you err on the side of caution, the better off you'll be. I don't recommend more than 12-12.5 psi on the street to anyone running stock turbos, especially with a stock intercooler. It's just not worth it to push an extra pound or so of boost in order to make a little more power at the risk of losing an engine. Play it safe and you'll have a far better ownership experience.

Again, read all you can on the subject and educate yourself. Invest in an RX-7 service manual so that even if you don't have to work on the car, or don't want to do the work yourself, you'll still be educated on how the systems function and interact with eachother. If you ever do have to work on your own car, it'll pay for itself with the first use.

Search the Internet for information. A good place to start is Steve Cirian's web site.

http://www.scuderiaciriani.com/rx7/

Steve has captured information from posts to the "main" RX-7 mailing list (rx7@world.std.com) which is predominantly 3rd gen. oriented. There are links to how-to articles on other sites and on his site, pictures, information, many different opinions on everything from single turbo systems to suspension components.

Good luck!

There isn't one, but you can modify your existing gauge...

http://www.geocities.com/sdrx7_club/Instructions.pdf

Has anyone linearized their temp gauge? Does this work? Are there any linear temp gauges we can replace the stocker with? I'm tempted to just say fuck it and get aftermarket gauges and install...tearing apart the gauge cluster isn't something that looks like fun :(

If you get a Power FC, you can monitor your motor temps to the nearest degree Celcius :)

Rich

What does AST stand for if you don't mind me asking....

Air Seperation Tank. The stock one is (shoddily) made of plastic and can burst, leaving you with a big mess under the hood and the very likely chance of overheating if you're driving while this happens.

Some replace it with an aluminum model, available from several vendors in various configurations. Some apparently work better than others, ask around if you're looking for a replacement to get opinions on the various models available.

Some just get an '89 filler neck with a hose fitting just below the cap and simply eliminate the AST altogether by running overflow directly to the catch can in the passenger's side front fender.

Both solutions work, but the '89 filler neck is about $49 from Mazdatrix, and the aluminum AST can run over $100. :)

Many people have run the AST elmination mod for thousands of miles without a reported failure that I've heard of, but some people believe that you absolutely must keep the AST (extra weight!!) and that the aluminum version is the best solution.

hey Jim, can u re-post the link for the temp gauge? thanx

This thread should not be reliability mods, but fanatical reliablity mods. Come on guys, these things are not that fragile, granted some big changes were made in 1994, and i have not exeprinced a lot of the things owners of 1993s have, but still. I propose a new reliabilty mod list for the not fanatical owner that will have there car 2-5 years, and is in good shap when theyt get it.

1. follow maintenace schedule in owenrs manual

2. Fix somehign if it breaks & aquire gauges necesary for this.

3. drive the piss out of it, and buy a new one when it gets too ugly. and don't be afraid to run it through the car wash, chances are the apint looks like piss already!

BTW, when the gauge moves on stock temp gauge, it i sgoing to to 108C, which is point 108C switch comes on. so you basically have 2 readings the middle one, then last ditch effort at 108C, turn headlights on, and needle will never move.

( turn headlights on, and needle will never move.) What do you mean by this?

what size silicone hoses do i need and how much of each type thx...

PUMPED!!!!!!!!!!!!!!!!!!!!!!1
 

Hey pumped, where you from? Do you own a blue montego with greddy exhaust by any chance?

Lol,

One thing that no one has really mentioned here is something that I consider a VERY VERY important reliability item.

FUEL FILTER!! Replace fuel filter every year; the thing is the same one they use in the Mazda Miata btw, it's pretty puny. Keep filter clean!!

Also, when checking coolant levels, I just found out yesterday, that taking off the rad cap on and off too much, will eventually warp the rubber seals, and it'll begin to leak. I used to take off my rad cap all the time just to be meticulous in my maintenance, and ended up having to buy a new cap yesterday, albeit it only costs $10 or so.:p

When checking for coolant levels, top off AST, and filler neck, and overflow tank to middle. Then leave the caps on AFTER you've checked the levels and they're consistent, don't take the rad cap off every other day, and the aST cap never really needs to come off.

You can check levels by overflow tank, if it's empty, something is wrong, check the rad cap. IF it needs some more fluids, fill via overflow tank.

THE MOST MOST MOST IMPORTANT
 

AS FOR ECUs...Power FCs are good, and so will any M2, or Pettit ECU.

But the MOST IMPORTANT RELIABILITY MOD for anybody with a modded 7 pushing any kind of serious horsepower is to ENSURE PROPER AIR/FUEL RATIO, and no OVERHEATING!

You really should do dyno tuning with a wide lambda air/fuel if you're planning to run for anything above 315rwhp I'd say, to be safe.

Too rich is not good, and too lean is obviously boom.

Don't spend $1000s of dollars on all the go fast parts, and then cheap out on the $200 dyno tuning session w/wide lambda like *MOST* people have a tendency of doing!

And at the very least, an EGT guage should be there right beside your BOOST guage. Watch the needle, it should never go above 700-750C at WOT.

Yo Moderators, can we archive this sucker? Lotta good info...