Cpt Gunmetal

Hey guys I have a '88 Rx7 SE with 194k miles. By the time I have the cash to make the final decision my 7 will most likely have 200k miles. I talked to some new friends today and they seem very knowledgeable about rotaries. One of the guys said that the stock engine in the SE is worth rebuilding and boosting. They gave me a price of about $2,000 for the rebuild. On the other hand, another person I know said a good idea is to buy the s5 and drop that in.

In short, I know people are going to be biased towards the engine they own/want. Honestly, I just want to know if you would rebuild and boost or drop an s5.

misterstyx69

iTrader: (142)

Sort of a loaded question.
If you are keeping it awhile then Rebuild it.
If you can sift through the s5 Engine swap "abnormalities" then go s5.
You would have to change a couple things,like the front cover,thinking about the OMP,Injector wiring connections etc.
It is not just a drop in and go swap.

Cpt Gunmetal

Ahh ok so how about the turbo2 motor swap or rebuild?

Cpt Gunmetal

I believe that's the drop and screw in and your good to go.

rotary miata boy

Drop the S5! If you are mechanically inclined. Its already turbo. Just know what your getting into. Plan accordingly.

Cpt Gunmetal

Haha well sadly I'm not. Totally green at this. Also how long could a 200k miled 13b be abused till it popped after a rebuild at 200k?

FiveOneOh

That's not really an answerable question... it could last for 2 blocks it could last for another 200 000... depends on who did the rebuild, how well they did the job, the parts used in the rebuild, and ultimately how well you care for your car.

linlan

I would say swap will be better.

Cpt Gunmetal

So just go ahead with the s4 t2 swap

chrismac

S4 swaps r pretty straight forward and easy to come by

midnightbluefc

iTrader: (19)

S4 t2 swap would be the easiest and cheapest. But even then I would advise u to rebuild the swap anyways, I had got 2 jdm t2 shotblocks and they were both garbage out of both of those I sent it out to get one rebuildable core. It's all up to u how many times do u want to drop the same motor in lmao.

Cpt Gunmetal

Alright well it looked like the t2 engine had around 50-60k miles on it. With that being said, when's a good time to rebuild?

rotary miata boy

When compression gets too low. If it gets below 70 you should rebuild.

Cpt Gunmetal

Gotcha. Lastly a guy I met was telling me that with the t2 stock turbo, all I would have to do to get around 300 hp is raise the boost?

Evil Aviator

No, the OEM fuel system is only good for about 200hp. For 300hp you would need to upgrade the fuel injectors and fuel pump, otherwise the engine will lean-out and experience a quick but ugly death. In addition, you need some way to control the fuel, so that will require an aftermarket fuel control unit like an Apexi AFC, a standalone EMS like a Haltech Platinum Sprint, or an upgraded ECU like the reprogrammed Rtek. A fuel control unit or standalone EMS will also require tuning by somebody who knows what they are doing, hopefully one that is bonded and insured in case they blow up your engine. You would probably also want to install a boost gauge, boost controller, and performance exhaust system.

Cpt Gunmetal

That is a lot of work! Ok that creates a few questions. One is where did you learn all that info that is required to do the boost increase? How much would you say it would cost for all those parts? Lastly, how would I know who is a good tuner to mess with the fuel control unit?

Evil Aviator

Yes, after 200hp there is some work involved, but if you stick in the range of the BNR hybrid and Rtek chip then it isn't all that difficult or expensive. The 400hp+ range is a real bear, lol.

I've been on this forum for a while.

It depends which parts you want, and whether you buy them new or used. Did you plan on buying a Turbo II hood so that you can use the OEM intercooler, or did you plan on buying an aftermarket front-mount intercooler setup? Also, the non-turbo drivetrain is not going to be suitable for 300hp, so you may want to take into account the cost of a Turbo II transmission, driveshaft, LSD, starter, clutch slave, and halfshafts. Depending on the level of the build, I would plan on $5,000-10,000 and 3-16 months for the project.

I would recommend that you either enjoy your car as a non-turbo, or sell it and buy a Turbo II car. You can get an OK Turbo II for about $3,000, or a really nice one for about $5,000-6,000. The swap sounds really great and all, but it is not something that a novice should attempt, despite how much your friends would like to see you suffer through it.

You can search your regional forum or ask them if there is a good rotary shop in your area.
https://www.rx7club.com/west-rx-7-forum-193/

1) Call a shop on the telephone.
2) Ask them if they could install and tune a fuel control unit on your rotary engine RX-7. If No, go to #1 and call the next shop. If Yes, go to #3.
3) Ask them if they are bonded and insured. If No, go to #1 and call the next shop. If Yes, go to #4.
4) Make an appointment to have them look at your car and discuss your goals (300hp, or whatever) and your budget. If you are not happy with their estimate, go to #1 and call the next shop. If Yes, then let them do the work, or shop around to see if you can get a better deal.

Not really related to your thread, but did you know that gunmetal is actually a brass/bronze color?

Cpt Gunmetal

About gunmetal that's news to me! Always thought it was that dark gray color.

That sucks that this car won't be able to handle a turbo. I guess that means the only option left would be to build up the engine. But is there a difference between making a 300 hp n/a or turbo car?

Evil Aviator

It can, but it will take some work.

Again, were it me, I would sell the car and buy a Turbo II if that is what I really wanted. However, I like the non-turbo cars just fine. I currently own one of each, but in my heyday I had 3 non-turbo RX-7s and 1 turbo RX-7.

Yes, 300hp NA is not going to be street legal. Turbos are nice because they soak up a lot of noise and they do not require major changes to the engine that make it difficult to drive on the street.

Me too, until I started hanging out with my local arms collectors club. The 1866 Winchester rifle receiver was made out of gunmetal.

Cpt Gunmetal

That would be an interesting color for an Rx7 lol!

So it seems like a turbo 2 would be a better buy then. Is there any other swap options that are easier or less costly? I am pretty green at this so I'm definitely trying not to go over my head with an insanely complicated project.

Evil Aviator

I have seen cars that were painted a similar color. Unfortunately, what was seen cannot be unseen.

Swapping in the same series of turbo engine is probably the easiest and cheapest of the various swaps. Your main problem with this is that you want more hp than the stock engine, which makes it more complicated. It wouldn't be quite so bad if you keep the engine down to 182-200bhp.

Common swaps include the 3Gen RX-7 13B-REW, Cosmo 13B-RE or 20B-REW, and various piston engines. These are all more difficult due to engine mounting issues and compensating for higher hp and torque. The below website shows piston engine swaps:
http://www.grannysspeedshop.com/

I have nothing against piston engines, but I think it is a complete waste of time to swap one into an RX-7 when there are so many American muscle cars available on the new and used car market.

Cpt Gunmetal

I see. My goal is to autocross and time attack. I don't know if I want to keep the fc all the way or choose something else later on down the road. With that being said, in your opinion, what would be the best route? Keeping the se as is and rebuild engine, doing the turbo 2 swap, or buying a turbo 2? Also how much hp can a turbo handle anyways?