Hi, I have 2002 STi with PPP. It is currently running at around 300 BHP. This was confirmed at a recent dyno run. I am looking to get an extra 20 BHP and have heard conflicting information on how to do this. From what I know the cheapest and easiest way to do this would be replacing the downpipe cat with a straight through pipe but some people tell me I would need to re map the PPP ecu to get gains. Is this true or would decatting the downpipe give me 20 BHP without anything else needing to be done?

any advice appreciated.

Doug

 

If you just change the downpipe you may get a small increase but could get boost problems.

You are best off getting a full 3"exhaust uprated fuel pump and remap, then you would get nearer 340 bhp

 

I think that if you just had it remapped by one of the respected mappers it would be possible to get that increase. Give one of them a call, I'm sure they will give you some good advice.

 

full decat and remap then you should be at about 330bhp give or take a few

 

Agree with escott, a remap alone on a PPP car should see you at 320bhp.

You don't need to change the exhaust to a 3" as the PPP one is fine up to at least 350bhp and you already have an uprated fuel pump.

I would suggest a high flow panel filter (like the green or uprated STi one) and some colder plugs PRF7B's to make the most of the remap.