IW STi Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
99 Posts
Discussion Starter #1
I am new to Subarus, can someone tell me what is required to make about 350whp? Do you need to sleeve the block? Would the rods hold? What about the pistons and rings? What about the injectors, are they at least 550cc?

I know that Link makes an ECU unit that can be used on Subarus, is it a direct replacement?

Is it pretty easy to work on the WRX/STIs?

Pls don't tell me to do a search, I have, and couldn't find the answer. I am seriously considering an STI, and already know what can be done on the Evo, so I just need to know a little more about the STI to make an informed decision.

Thanks
 

·
Registered
Joined
·
199 Posts
the Sti's motor is new, so there will be a little bit of a learning curve at first as people figure out what works and what doesn't. The general feeling that i've gotten from people who claim to be "in the know" is that the internals are very robust and should support lots of hp without modification.

the STi has a brand new ECU and it will be a while before people hack it. but yes the link ECU does work on wrxs. there are a bunch of ECU replacements for the EJ-20.

wrx isn't too hard to work on. it's not a 60's era muscle car, so the engine bay is a little tight if you have big hands, but you don't have to drop the engine to change the oil filter if that's what you mean.
 

·
Registered
Joined
·
176 Posts
I would think that with a simple ECU upgrade that you could easily push HP to 350 at the crank (raising boost to 14.5 to 18.5). The engine internals are much stonger than the WRX, as is the transmission, so I think 350-400HP would not be a problem for the stock internals.

Hopefully ProDrive makes one soon so that your factory warranty remains in tact. :wink:
 

·
Registered
Joined
·
199 Posts
Get Paid $50 to Test Drive a Subaru

i think 350 at the crank will be pretty easy, but hatchy's looking for 350 at the wheels. that may take a little bit more.
 

·
Registered
Joined
·
59 Posts
well, I am suprised by the optimism in this thread. Not to say that I know too much about it, but what do you think that pushing the engine close to 400HP would do to reliability? I know it is impossible to say until some people start doing it....but I know I wouldnt want it to be me who finds out that upping the boost too much with the stock internals blows the engine. :-?
 

·
Drive True
Joined
·
6,833 Posts
I don't know too much about modding and reliability, but if the STi is running slightly lower boost than the WRX, but has an even more robust engine, I would assume 350 whp is do-able. Assuming the same drivetrain loss compared to the WRX, that's about 470 hp at the crank...

Prodrive already has a stage 3 kit for the WRX which produces 228 whp, an increase of 35%. A similar kit for the STi would produce 300 whp, assuming it would give it the same kinds of gains. This isn't even increasing boost or modding the intake! Then there's Easystreet Motorsports that created the 740 hp WRX...

Now a 1000 whp STi...that's a different story :D :lol:
 

·
Registered
Joined
·
357 Posts
Yep that's me. I will have even more power on Monday. I ran out of time Friday to finish the batch of tests I wanted to run. I'm already making 301 whp easily and I think I can probably reach around 320 whp with simple bolt ons which is around 400 HP at the crank. The motor is complete unstressed at this power level.
 
1 - 9 of 9 Posts
Top