Just a quick question really. Was wondering what power you could run a 2005 sti safely on standard internals, with the 2.0ltr top end and the 2.5ltr sti bottom end? Reason i ask is that i heard the 2.5 bottom end isn't as strong as the 2.0ltr? Thanks for taking the time to read this

 

Around the 400 mark i've read. Maybe ask in Gen Tech. They're a knowledgable bunch with teccie stuff and many tuners reply in there.

 

I've been advised that approx 440bhp on a 05 STI 2.0ltr. Above 400lbft and the clutch will possibly be on borrowed time.

Don't know about the 2.5ltr.

 

400hp is pushing it on stock 2.5 internals. A set of pistons is all you need to push that to 450+.

 

ok guys thanks for that. Had the car running at 420 on the 2ltr bottom end but the pistons went, thats the reason for having the 2.5 in it now. currently been mapped to 340 just to be safe but seems a little bit tame compared to how she was.

 

Shame some forged pistons couldn't be added at the rebuild.

Can you post up a RR graph if you try for nearer 400 hp?

Nick

 

But what sort of torque figure ?

I know of at least one making 300 bhp but nearly 400 lb.ft of torque....

dunx

 

torques around the same at the min. when car was running at 420 it was around 400lbft. can you buy direct replacement pistons for the 2.5 or would i need to bore anything?

 

anybody?

 

I believe you can get 'drop in' forged pistons mate.

Give David at APi a call for advice.

Ns04