My 79SA Mods to date
08-02-15, 08:57 AM
#1
My 79SA Mods to date
Hello all. I have been here for a while poking around, and trying to make my 79 more fun to drive. I have a target of 155 hp, and being I bought a new Racing Beat exhaust system, I guess I am committed to try to achieve it as a NA motor.
So I bought this new system, it includes a header, a front resonator and a muffler. There is one factory pipe that is re-used. My stock exhaust is in terrific condition. The car shows 29k on the clock, and the body is beautiful with original paint, and no rust, but sometimes I question the mileage.. Some items look like very little use, and others sure look aged. I am not sure at what point age will overtake use in how parts deteriorate. The car came to me as an automatic trans car....not too much fun...
I hunted up all the pieces to convert it to a 5 speed, including a flywheel from a fellow on this site. Very nice guy. However, when I picked up the flywheel to put it on my lathe ( I wanted to resurface it) it dawned on me the immense weight this little motor would have to overcome to get this flywheel spun up. So, again I call racing beat, and bought a 17lb steel flywheel. This flywheel is neutral balanced, so I simply unbolt the torque converter flex plate, and bolt this on. I am still shopping for a new 225mm clutch. My original concern was that the lighter flywheel may make take off a little tricky, but I am hoping that the 17lbs, and the original counterweight are enough to make it ok. My plan is to re-gear to a higher ( numerically) gearset if the flywheel seems too light for take off. The rest of the trans conversion seems to be a bolt on affair. Even the cross member mounts are there for both trans options. I decided to run the trans as it came, and if needed, rebuild it at a later time.
So, back to the motor and my goal of 155hp. I came up with that goal by comparing the weight and power to my MX5, which although no powerhouse, is a blast to drive. If I can reach that point in my 7, I will be happy indeed.
I have already installed an electronic distributor. Bone stock 1983, so no timing advance tricks yet. I have also did all my tune up items, plugs, wires, fuel filter, cap rotor and so on. I will save the ignition fine tuning for later. The air pump is removed with the RB exhaust, so I free up some parasitic loss there too. Currently ( at least before I took it apart for these upgrades) it ran fairly well, with a stumble that was very pronounced at near 2200 thru 3100 rpm. I had thought that the transition/mid circuit had some blockage.....
So my next step will be induction. I will probably source a good used Nikki carb and read up on some of Jeff's posts. He has so much knowledge on the subject. I can't even imagine the time he has spent learning the details.
So off I go to hog a Nikki. Hopefully it works well. I feel as this is where I need to make up my power, and I think it is possible, It will not be easy, but probably it can be done. If I fall short of my goal, then off with the RB header, and then I will read up on the boosted Nikki prep, and I will begin to turbocharge.....
Ultimately, I am trying to gain a streetable, reliable, 155hp out of an NA 12a. I don't think that is too lofty a goal....or is it?
I am going to install new positive and negative cables while I am doing this work as it is time. The originals are beat up from years of new batteries and improper handling. I have seen cables that look fine, but have high resistance due to internal corrosion. This can cause headaches.
So in closing, I ask for anyone who has input to help me please. Ideas from this 7 community are priceless.. I can hopefully pay the community back by helping someone else. Somehow, I feel that a turbo is in my future. I am a tinkerer by nature. No car project of mine is ever truly done. I like working on them as much as driving them...
So there is my story, I am making progress, but I will need help, I welcome the ideas
Thank you
Rich
So I bought this new system, it includes a header, a front resonator and a muffler. There is one factory pipe that is re-used. My stock exhaust is in terrific condition. The car shows 29k on the clock, and the body is beautiful with original paint, and no rust, but sometimes I question the mileage.. Some items look like very little use, and others sure look aged. I am not sure at what point age will overtake use in how parts deteriorate. The car came to me as an automatic trans car....not too much fun...
I hunted up all the pieces to convert it to a 5 speed, including a flywheel from a fellow on this site. Very nice guy. However, when I picked up the flywheel to put it on my lathe ( I wanted to resurface it) it dawned on me the immense weight this little motor would have to overcome to get this flywheel spun up. So, again I call racing beat, and bought a 17lb steel flywheel. This flywheel is neutral balanced, so I simply unbolt the torque converter flex plate, and bolt this on. I am still shopping for a new 225mm clutch. My original concern was that the lighter flywheel may make take off a little tricky, but I am hoping that the 17lbs, and the original counterweight are enough to make it ok. My plan is to re-gear to a higher ( numerically) gearset if the flywheel seems too light for take off. The rest of the trans conversion seems to be a bolt on affair. Even the cross member mounts are there for both trans options. I decided to run the trans as it came, and if needed, rebuild it at a later time.
So, back to the motor and my goal of 155hp. I came up with that goal by comparing the weight and power to my MX5, which although no powerhouse, is a blast to drive. If I can reach that point in my 7, I will be happy indeed.
I have already installed an electronic distributor. Bone stock 1983, so no timing advance tricks yet. I have also did all my tune up items, plugs, wires, fuel filter, cap rotor and so on. I will save the ignition fine tuning for later. The air pump is removed with the RB exhaust, so I free up some parasitic loss there too. Currently ( at least before I took it apart for these upgrades) it ran fairly well, with a stumble that was very pronounced at near 2200 thru 3100 rpm. I had thought that the transition/mid circuit had some blockage.....
So my next step will be induction. I will probably source a good used Nikki carb and read up on some of Jeff's posts. He has so much knowledge on the subject. I can't even imagine the time he has spent learning the details.
So off I go to hog a Nikki. Hopefully it works well. I feel as this is where I need to make up my power, and I think it is possible, It will not be easy, but probably it can be done. If I fall short of my goal, then off with the RB header, and then I will read up on the boosted Nikki prep, and I will begin to turbocharge.....
Ultimately, I am trying to gain a streetable, reliable, 155hp out of an NA 12a. I don't think that is too lofty a goal....or is it?
I am going to install new positive and negative cables while I am doing this work as it is time. The originals are beat up from years of new batteries and improper handling. I have seen cables that look fine, but have high resistance due to internal corrosion. This can cause headaches.
So in closing, I ask for anyone who has input to help me please. Ideas from this 7 community are priceless.. I can hopefully pay the community back by helping someone else. Somehow, I feel that a turbo is in my future. I am a tinkerer by nature. No car project of mine is ever truly done. I like working on them as much as driving them...
So there is my story, I am making progress, but I will need help, I welcome the ideas
Thank you
Rich
08-02-15, 01:17 PM
#3
The light steel flywheel from Racing Beat is 13 pounds. The rear counterweight is 4 pounds. Together they make a 17 pound assembly.
Don't worry about it. These cars are actually improved with a light steel flywheel. The original one is 30 pounds and was heavy enough for a rotary truck, and even they were too heavy! I've since swapped my truck to a 24 pound flywheel with the matching rotating assembly (S4 NA rotors) and it was a great improvement all around. I plan to boost it next.
My RX-7 is a GSL-SE, considered a heavy chassis, and it has a light steel flywheel. It does great! I would not want anything much heavier or lighter. They should have came from the factory like this! Not the dumb 26 pounder.
Get yourself a stock duty 83-85 clutch kit from Mazdatrix. Look for the Exedy brand name. These will handle far more than your goal of 155HP. They even handle a turbo!
Too many noobs get a clutch setup that is rated for way higher than they need and end up not liking the heavy pedal, such as the Exedy stage 1. Don't get that one. Get the stock duty one unless the stock duty slips. In fact stock duty can be considered overkill at 225mm because your car's original setup came with a 215mm disc and pressure plate. I even ran a 215mm stock duty disc and a centerforce pressure plate with my turbo and it could break them loose in gear on dry road in 3rd. Don't mind me, I like typing that line.
By the way there is a step height different between the 215mm and 225mm pressure plates so that is something to be aware of. There is a special bolt kit from Mazdatrix and I think Racing Beat sells them as a kit as well. This kit allows for the about 10mm of step height difference using long bolts and aluminum spacers.
As for getting 155HP, I think a hogged out Nikki will get you there. Also look into an electronic distributor upgrade if your car is a 79 that still has points. Then look into direct fire.
Get thick battery cables. Think 2 gauge for positive and negative. Then get another cable with ring terminals at both ends to add a dedicated ground from engine to chassis. Also consider how you will connect the battery to the chassis if you don't like daisy chaining from the battery, to the engine, to the chassis. I think I've done I've done it both ways and they both worked.
Ok, I just read a little more of your post instead of just scanning randomly and it looks like the dizzy was already swapped. You mentioned advance. Not much to gain there. Just set it to the leading mark on the pulley with the engine off. This is called static timing and works fine. Then you can leave the vacuum advance off and look at the mark with a timing light. There should be a clean spot on the flat plate where the nut or bolt tightens. Usually the factory clean spot is where you want the dizzy to be, but not all the time (sometimes the factory guy who installed the dizzy was slightly hung over from too much sake the night before, so factory settings aren't always 100% right). As for hooking up vacuum advance, I don't bother. Maybe I should? You can't use it with boost so I don't really even think about it anymore.
By the way you will need a semi-locked dizzy for 10 degrees if you want to boost. Forget fully locked. That way sucks and is not recommended. You will also need an 81-85 carb because I had lousy luck with 79-80 and boost so I can't recommend them.
Don't worry about it. These cars are actually improved with a light steel flywheel. The original one is 30 pounds and was heavy enough for a rotary truck, and even they were too heavy! I've since swapped my truck to a 24 pound flywheel with the matching rotating assembly (S4 NA rotors) and it was a great improvement all around. I plan to boost it next.
My RX-7 is a GSL-SE, considered a heavy chassis, and it has a light steel flywheel. It does great! I would not want anything much heavier or lighter. They should have came from the factory like this! Not the dumb 26 pounder.
Get yourself a stock duty 83-85 clutch kit from Mazdatrix. Look for the Exedy brand name. These will handle far more than your goal of 155HP. They even handle a turbo!
Too many noobs get a clutch setup that is rated for way higher than they need and end up not liking the heavy pedal, such as the Exedy stage 1. Don't get that one. Get the stock duty one unless the stock duty slips. In fact stock duty can be considered overkill at 225mm because your car's original setup came with a 215mm disc and pressure plate. I even ran a 215mm stock duty disc and a centerforce pressure plate with my turbo and it could break them loose in gear on dry road in 3rd. Don't mind me, I like typing that line.
By the way there is a step height different between the 215mm and 225mm pressure plates so that is something to be aware of. There is a special bolt kit from Mazdatrix and I think Racing Beat sells them as a kit as well. This kit allows for the about 10mm of step height difference using long bolts and aluminum spacers.
As for getting 155HP, I think a hogged out Nikki will get you there. Also look into an electronic distributor upgrade if your car is a 79 that still has points. Then look into direct fire.
Get thick battery cables. Think 2 gauge for positive and negative. Then get another cable with ring terminals at both ends to add a dedicated ground from engine to chassis. Also consider how you will connect the battery to the chassis if you don't like daisy chaining from the battery, to the engine, to the chassis. I think I've done I've done it both ways and they both worked.
Ok, I just read a little more of your post instead of just scanning randomly
and it looks like the dizzy was already swapped. You mentioned advance. Not much to gain there. Just set it to the leading mark on the pulley with the engine off. This is called static timing and works fine. Then you can leave the vacuum advance off and look at the mark with a timing light. There should be a clean spot on the flat plate where the nut or bolt tightens. Usually the factory clean spot is where you want the dizzy to be, but not all the time (sometimes the factory guy who installed the dizzy was slightly hung over from too much sake the night before, so factory settings aren't always 100% right). As for hooking up vacuum advance, I don't bother. Maybe I should? You can't use it with boost so I don't really even think about it anymore.By the way you will need a semi-locked dizzy for 10 degrees if you want to boost. Forget fully locked. That way sucks and is not recommended. You will also need an 81-85 carb because I had lousy luck with 79-80 and boost so I can't recommend them.
08-03-15, 07:21 AM
#5
Waffles - hmmm good
iTrader: (1)
I think I said this to you before, but with my Dell and my old RE exhaust I dynoed at 134HP at the
wheels. DO some math and that pretty much your magic target of 155 or so.
Sound like you didn't get the RB Street Port exhaust setup. Should have because its a lot better at
all rpm ranges than the early collected RB header.
Theres basically 3 things you have to do to reach your goal:
1. Free flowing exhaust which you have.
2. Better fuel flow which you are starting with the nikki hogging.
3. Better ignition. You have the right dizzy now you need to consider a direct fire setup. The
ignition is a real weak spot that very few address. It can make a huge difference in starting and
running well.
You do all of these and maybe an electric fan and I'm sure you will not be disappointed. The next
step you will want to modify the suspension to take the corners and the extra HP better. It will
never end.
wheels. DO some math and that pretty much your magic target of 155 or so.
Sound like you didn't get the RB Street Port exhaust setup. Should have because its a lot better at
all rpm ranges than the early collected RB header.
Theres basically 3 things you have to do to reach your goal:
1. Free flowing exhaust which you have.
2. Better fuel flow which you are starting with the nikki hogging.
3. Better ignition. You have the right dizzy now you need to consider a direct fire setup. The
ignition is a real weak spot that very few address. It can make a huge difference in starting and
running well.
You do all of these and maybe an electric fan and I'm sure you will not be disappointed. The next
step you will want to modify the suspension to take the corners and the extra HP better. It will
never end.
08-03-15, 10:14 PM
#6
teaser
Hello all and thanks for the replies. I will start adding these items as I get a minute. I am involved in a software conversion at work, so life is beyond hectic.
No, I didn't buy the long header system because I simply didn't read far enough down their site. I saw the first one that fit my car, and wrongly assumed that was it.
I will tune to the set up I have. Like I said, I sense a future turbo, so I would eventually be removing the header.
The RB order guy told me 17 lbs on the flywheel, which I questioned, due to the fact that their site says it is 13 lbs. My guess is either I am not clear, or the order taker was outright wrong. The latter is my guess.
So I will do the ignition mod shortly, as I can imagine a nice benefit there.
At any rate, I have posted pix before, but I figured I would post one pix of the car, and I will take more of the work when I get back at it..... Then to suspension and so on and so on and so on!!!!!!
Thank you all
No, I didn't buy the long header system because I simply didn't read far enough down their site. I saw the first one that fit my car, and wrongly assumed that was it.
I will tune to the set up I have. Like I said, I sense a future turbo, so I would eventually be removing the header.
The RB order guy told me 17 lbs on the flywheel, which I questioned, due to the fact that their site says it is 13 lbs. My guess is either I am not clear, or the order taker was outright wrong. The latter is my guess.
So I will do the ignition mod shortly, as I can imagine a nice benefit there.
At any rate, I have posted pix before, but I figured I would post one pix of the car, and I will take more of the work when I get back at it..... Then to suspension and so on and so on and so on!!!!!!
Thank you all
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