Not referring to you Jim, but it is funny how you took it.There are a lot of things on here people shouldn't be doing, most of the people on here shouldn't even own this car, and not because they aren't good enough for it, but because they get in way over their head, and listen to too many people on here who's car isn't even running right themsleves. Day in and day out I see these cars eat their owners alive, they are great cars with tons of potential, they just aren't for the kid wanting to street tune it and go wrap himself around a pole.
Are people doing it? Yes. can it be done? Yes. would I do it on 93 octane? No. would I recommend it to one of my customers? No. Most can't handle their cars as it is, let alone trying to experiment with it, then some of us yourself included are never satisfied even when it's good it could always be better.

 

Forgive me if I missed something, but are you seriously considering doing this on a stock '93-95 ECU and no fuel mods listed?

From my days in the Subaru scene, a lot of guys added turbo to their 10.5:1 CR Impreza 2.5RS's, and the guys with anything less than full standalone EMS always blew holes in their #3 pistons, even with minor fuel upgrades. Rotaries are even more damaged by detonation dud, I would highly suggest you reconsider.


Upgrade your ECU first, stock is only 8-bit. Ask an electronics guy the difference between 8-bit and 16-bit; it's huge. Or even simpler, just think of all the electronics technology that has improved since 1995, are you still using your desktop PC that's even 5 years old?

-scott-

 

Is it possible to upgrade the stock ECU to the 96-2002 16 bit one? On an FD 93? Would it be compatible?

 

You'd have to use the wiring harness from the new 16- bit ECU also, the connectors (and inputs/outputs that the ECU is using) should be different also.

-s-

 

Meh to much trouble huh? Just go with a PFC or some aftermarket.

 

lol, I love it when people with no clue start chiming in. Upgrade to 16bit!

rofl..


Personally I would not upgrade the compression in an effort to get power down low. I would go back to the original seq. set up. If thats not an option, than I would opt for the Apexi RX6 or simmilar single. Quick spooling, much faster than your current setup, and alot more on the top end too.

Best bang for your buck though is going to be switching back to seq, getting a pfc, and tuning for 89 octane. You will get better, safer power this way. You will end up with more hp in the end also.

Just remember, most companies lower the compression on turbo'd motors. They cant all be wrong??

 

From what I understand the high compression rotors really do help out with regaining the low end people lose once they convert over to a single. They also help spool larger turbos faster without having to go with a smaller A/R's which could possibly choke the engine in the upper rpm's.

Personally I think it's a good idea if your going to run non seq. You would regain some of the low end benefits of the seq setup but have the higher flowing capabilities of non seq's. All this with lower boost.

 

Have you ever driven an FD with the RX-6? I have been *very* underimpressed, esp for the price of that kit. It doesnt make much more power than the stock twins. It does spool quickly, but doesn't pull to redline like, say, a GT35/40. The turbine is just too small. It does really clean up the engine bay vs stock seq, which i believe is the only real benefit.

Rich

 

you can't cool what the engine compresses but you can cool the turbo.

If i'm correct in say'n, that's why high boost is done with low comp rotors b/c you can cool the air from the turbo.

Increasing CR is quite different than adding a turbo.

they dont' alway lower compression when turbo'n. Mazda has increased it from 8.5 to 9 from s4 to s5.

With these 9.7 i'll prolly invest in a haltech.

I will not upgrade my fuel system b/c my hp will not increase beyond my ability to supply. Hp is not why i'm doing this and is not that big of a bump.

Are there any FD owners that lower the compression? You lose the machines surfaces but wouldn't be a big hit.

I just figured more ppl would experiment with CR and i could get some more feed back on what i needed to do this properly.

guess i'll find out for better or for worse

 

I did... 11.4:1.

 

A lower compression chamber has more volume during the intake phase (stroke) than a higher compression chamber. In the pressurized application of a turbocharger you want the largest chamber possible to fill with that compressed air. The larger the chamber size the more pronounced the effect of having the turbo. The higher compression rotors are having the effect of creating a smaller displacement motor. You can't make a stroker eccentric shaft heh.

Kevin T. Wyum

 

Jim what octane do you have to run with that compression? Im guessing you would knock on 93

 

Nope. Static compression ratio and dynamic compression ratio are two different things. Sort of like static weight distribution and dynamic weight distribution...

 

Hmmm....... back from the dead. Anyone else have experiences with higher compression ratios? I'm especially interested in failures.

 

Heh- saw the old post

I went with stock 9's on the rebuild and RA kit.

Pulling the motor soon b/c 5th gear syncro and putting on single (62-1) with a E6X.

I actually picked up a S5 NA for about 200 bucks with 30k miles on it in pristine condition (wreck).

I do plan on running it with a turbo but in a gutted 87 TII.

I jsut don't feel like rebuilding the FD motor since it ran strong and is alot of work >.<

After doing a single Turbo FC with e6x it only makes me want to try it more.

I will do this, just a question of when -.-