Hello,

Do STI engines have forged internals?

Anyone know a good website to find out about them? Wikapidia is a bit limited, I want to know what is different about them and how they got the BHP up. I have a V5.

Cheers

 

what year?

 

I've got a V5 which is a 1999.

 

dont think so

 

Yes your MY99 version 5 STI does have forged pistons, rods are the same as any other turbo model though

Tony

 

Thanks Tony

 

what about newage 02 on ?

 

All 2ltr STI cars up to 2002 had forged pistons, then there are some changes with the MY03 JDM models which use hypereuetic (sp) cast pistons, uk cars continued to use the same 2ltr engine up to 2005 until they changed to the 2.5 ltr unit (which didnt use forged pistons).

Tony

 

Hi tony so not all Sti new age have forged pistons, I thought all 2.0 had forged pistons ?

 

Nope not all, the twin scroll JDM cars dont, those are 2ltr though, the 2ltr new age engines all had forged pistons (single scroll turbo), 2.5's have hypereuetic pistons (though not as good as the 2ltr twin scroll cars ) and all classic STI's had forged pistons.

Tony

 

I do a few track days in my 2006 sti 2.5 its running 340 bhp mapped by JGM not had any problems yet , touch wood , am i best just revving it to about 5,500 rpm to save any damage to the pistons.

 

Tony have you got your own tuning company as you seem to have all the answers,LOL.

 

His like a sponge when it comes to Subaru Tony does the 02 sti's have H rods as standard? I was told this by a well known specialist and just curious if its true!

 

Not sure about the rods but I have been told by some of the more knowledgable on here that the rods are the same on all the new age cars (ie better than the classics )

Tony

 

cheers for that, its nice to know that the car has forged pistons and better rods as standard

 

Although better to have forged than not... Subaru OEM forged items are, allegedly, "not all that" - certainly the pistons/rods found in Classic STi's. This is the opinion of a well known specialist (via the experience of vast numbers of rebuilds and therefore observation...)

 

Joz, you have to remember that forging is just a process, yes its the best way to strengthen the pistons (or any metal for that reason) but there are better designed and stronger forged pistons out there

Tony

 

Yeah, that's what I mean!

Subaru, to save miilions no doubt, will have cut the forging process to a 'minimum', just so they can legally market, "The STi is fitted with forged...", IYSWIM.