GodSquadMandrake

I have a clean 86 S4 NA and I want a 500 HP turbo motor. What would be the best way to approach this. Should I start with an aftermarket ECU and a custom wiring harness or try swapping in the turbo wiring harness and ECU? Which engine do I start with? S4 turbo, S5 turbo? Or 13B-REW? I know Aaron Cake has a 387 HP NA S4 with high compression rotors but I'm not sure if that is the best. Which transmission and rear end would I need that wouldn't explode?

DrKillJoY

No offense, but to be fair... if you haven't done enough research to know where or how to start, I'm not sure your going to have the skills to do it on your own.

Some guys have been building engines for years and not gotten close to 500 hp on a rotary... and I surely hope you don't expect to drive it around (regularly) on the street. You aren't going to get near those kinds of numbers without some MAJOR work on the complete drivetrain, suspension and safety systems of the car.

WaachBack

iTrader: (21)

13BREW with a large frame turbo.

Also, if you really have to ask, you need to be doing more research.

However, 500whp these days is not that hard to attain with A/I, porting, and a large turbo.

sen2two

iTrader: (10)

whats the reason you want 500? bragging rights or track use?

It really isnt that hard. But will take big money and a looong time if your just getting started. the people that have 500+ HP. dont need to ask these questions... Now i understand everyone has a starting point. But dont set your first build bar so high. you'll be upset in the end when your parting out your car cause you cant afford to finish it...

Im on my 5th turbo motor set-up on this one car alone. and im just now setting my HP goal to 550. but the number means nothing really, i just know i need a certain amount of HP to reach my quartermile time goal... and 550 is about it. if i could run my time with only 400, i would build mine to 400.

just take it slow, and build up to it and gain some experience/knowledge...

spr258

iTrader: (3)

As long as you know it takes a lot of time and money then you will be fine. Take it slow. You are going to have to go with an aftermarket single turbo setup. When you start the build build it slowly and dont keep the car down for to long. If you keep it down then you might get discouraged.

Start with a lower HP number and build up. I started with a 350 hp car and have been building it faster and faster. 350 hp on a dd is more than enough. I know what it takes to make a FD into 500 hp. Sorry I dont know much about a FC.

GodSquadMandrake

Ok agreed 500 HP might be a little much. Start small and work my way up... ok this sounds like a reasonable way to approach it but it's a little different from what I'm used to. With my Subaru I knew what my HP goal was so I purchased internals that would be sufficient to handle that, a turbo that would deliver that kind of power, injectors, etc. Because nothing is worse than building a motor and then wanting to get more and having to tear down the whole thing and start from scratch. I guess I would rather overbuild it a little and never have to worry. Isn't it like that when you rebuild a rotary too? Don't you have to pick the right apex seals, porting, rotors, maching work etc? I hear about a lot of guys going through like 6 or more motors. What's with that? I'm very safe with my rebuilds on piston engines and I know that every one I rebuild will probably last past 100,000 miles and never need to be touched again.
I hear the GT35R turbo would be a good one that could help me reach my goals. I know Garrett makes a kit too that doesn't look too expensive but that kit was for the 13B-REW. I know people have said the 13B-REW is stronger, but the motor mounts are in different places and obviously it would require a lot of work in the engine bay plus electrical.

spr258

iTrader: (3)

You can over build the car without a problem. That is what i did. I guess the shop knew that I would want to make 500 hp eventually. You will have to match the ports to the turbo to get the best out of it. You will have to decide on if you want to street port or bridge port.

The tune is what most people dont do right and try to get the most out of a motor. Detonation kills our motors. I dont think you will ever get 100,000 miles out of a high hp motor, but that is just me. I know that howard colman has done a lot of research and knows how to build a motor.

sen2two

iTrader: (10)

seems like your not brand new to building cars, just Rx7's. 500 HP is easily achievable on stock ports TII and no machine work...

basically just need strong apex seals (RA super seals), a decent turbo(GT35, HX40, PT67, ect.), and a good tuner... thats it.

keep it safe with 50/50 water meth injection. a good ECU is a Microtech, Haltech, and Apex-i PFC. just make the Rotary tuner in your area is comfortable with the ECU you choose. This will make the biggest difference in the end...

wackaloo13

iTrader: (3)

get a 13b-re or a 13bt out of a s5 with the thicker casting on the rear plate. Use a gt35rs (aspec 500r) and run some meth or water. New IC setup is a must or you are going to need a crapload of alcohol. You will need a standalone. Get a good clutch. You can also go for a 20b but that is pretty expensive. you are probably better off buying a TII and using that as a starting point so you dont have to deal with converting the drive train over to the TII or going completely custom.

rotaryinspired

iTrader: (3)

You will be maxing a 35r at 500. Go bigger. S5 TII block or 13b-re port it for the motor, haltech for ECU.

Its easy to get to the 425 area now days. The problem is that everyone tries to cut corners.

The key is to keep it cool. Heat is your enemy in this motor, more than any other power plant. Remember that and you will win.

You will never have low end power or torque. Your powerband will be between 4 and 8K. My car is still making power at 9500 rpms with a very large street port. I have a T67 w/ a .96 A/R exhaust housing.

Good luck and do a lot of research. There is good and bad info on this site sometimes its hard to sift through. The stickies are a good place to start. If you have rebuilt other motors the 13b will seem too simple.

rotaryinspired

iTrader: (3)

One more thing. 87-88 TII rotors will allow you to run more boost. They are 8.5:1 and my preferance for big power. Again think less heat. You can get very close or at 500 on pump gas. good luck.

GodSquadMandrake

Thanks guys