Non Sti and Sti rev limits
 

What actually makes the difference in allowing an STI engine rev to 8000 rpm and and a non-STI engine only rev to 7k?

My STi version 1 redlines at 7k,then after that other STi's (v2 - v7 i think) hit 8k but later STi's are back down to 7k. Might be due to ECU mapping (v2 -v7) then relialabilty issue's, subaru dropped it back to 7k. Dunno if im right tho :wonder:

sti2 7 too. V3 on was 8250

Forged pistons help ;)

Tony:D

sti's have a stronger block and internals, hence allowing them to take more abuse fromt he owner

It's uk sti's that are 7k, JDM ones are still 8.

Do you not find you just run out of revs too fast with 7k? I do..

Only the very early STis had a stronger block - and then mostly the RAs.

Most STis do did have forged pistons which is the main difference - they are lighter. They also had different cam profiles which makes it easier.

Hydraulic cam lifters?

My V.2 STi redlines at 7000rpm, it came with forged pistons as standard.

Apparently not all of the V.2's came with forged pistons, it was a bit hit and miss at the time wether there are forged pistons and under piston oil squirters.

isnt it the closed deck blocks that have the under piston oil squirters?
Also the stronger block ( I take it you mean closed deck block) wasnt only with the sti's but also with the earlier wrx's as well. However the open deck block is strong enough for over 400bhp anyway.

So answer to the question is different cam profiles, uprated/lighter internals, different ecu

IMO it's mostly down to lighter pistons and stronger valve train.

Richard

I think that the V.2 STI blocks were closed, yet mine does not have under piston oil squirters!

I thought the higher rev limit was capable due to solid lifter as opposed to hydrolic lifters used on non sti engines.

Nathan

UK sti redlines are at 7.5k, the wrx is still 7k.

That was the reason I asked. With the remapped TD05, I find you get to the limiter very easily and very quickly and the car's still pulling loads, so I was interested in whether the limiter could be moved further up the revs if possible.
I've got a non-STI UK though, so it doesn't look too good :cry: