exhaust
 

I have been serching around the web and i could not find a HKS or GREDDY turbo back exhaust. Which one do you guys preffer?

There is not a lot for the Sti I would work on the ecu mapping first turbo back could be real harmful. Two words boost spike ooouuucchh!!!
Sti is not a wrx I you are looking for horse power you have it if you are looking for noise get a cat back and a up pipe! But do your homework ask
S-squared nate knows his stuff Cobb is coming out with stage packages for the Sti :!: cobbtuning.com/sti/

Yeah, be careful...However, If I had to choose a T Back, I'd go with the Perrin or PDE/Injen setup.

So should i do the ECU reflash?

Well, so far, the only mod that will guarantee no boost creep is porting the wastegate. Otherwise, freeing up the exhaust all the way, and making significant increases in air movement will lead to boost creep, which can really hurt the engine, as it starvs for fuel.

Now, retaining at least one cat will help prevent boost creep, but that's not a guarantee. At our altitude, I'd be willing to run a Turbo back with 1 cat and take my chances. However, at sea level, the car may have issues.

I think the best formula is to run an ECUtek reflash with a turbo back retaining at least one cat, maybe 2? ...

Check out this threadfrom NASIOC. It has some great technical discussion on the matter.

That thread cleared up a lot of my questions. Thanks. So.... now that i know you have to port your wastegate do you think that would be the safest and wises thing to do?

If i do port the wastegate what do i port it to? do i need a Measurement down to the thousands?

Yes, to be absolutely sure that boost creep won't kill the engine, porting the wastegate is the only way. It is a safe mod that works. I would definately do it if I planned on tuning the engine that far.

Now as far as who I'd have do it? I'm not sure...I don;t have the tools to do it myself, and I'm not sure who does work like that. I'm sure most engine shops that work on heads could handle it.

As far as the actual spec, I don't think there is an exact spec required. I've seen that people are opening the hole up and polishing the inside of the chamber to help the air flow.

I would take advantage of NASIOC.com and I-Club.com. If you check out the 2.5L forums and use the search, you'll find a ton of discussion, pictures and ideas regarding this subject.

My only real recomendation is...do your homework before deciding, the 2.5L in our cars is a great engine, it can make a ton of power, but make sure you base your decisions on power AND reliabilty.

I'm looking forward to the work you'll do on this car,,it should turn out to be a track beast.

Just a note,, Check out esxmotorsports.com. They built a customer's STi to run track days. It is VERY well sorted in all aspects of suspension, power, brakes and tuning. It has a lot of mods, including turbo upgrades. m I don't think it's on their website, but I checked it out at buttonwillow. You can call them and ask them about "Russ's car". And tell them what you are looking to do.

FWIW, I am a big fan of good custom setups over the "name-brand" ones. Among those however, my favorites are Stromung and the Borla Hush. I don't like the sound from the ricer JDM exhausts though.

I defently want to go for reliability over power however, I know as soon as you upgrade the vehicle that you are taking a chance with the cars reliability. I ts a chance that I am whiling to take(hopefully i make smart choices)
I already know who I am going to have do the work (acufab, out of Carson). I just need to find out how much to port it and get a few photos to make sure it is done properly.