what is the max level these can take? Ive been reading about the AE black sti from greece and he said that it was 1.4 bar, but ive seen 'remapped' newages hitting 1.5 bar and mine peaks at 1.3

so what is it?

thanks

dan

 

What model Sti?

If it's a classic or early new age with Forged pistons then 1.5 bar+ should be ok, provided it is mapped correctly, hoiwever if it is a later newage (from '03 IIRC) then it will have Hypereutectic cast pistons that have a nasty habi of cracking around the ringland, and running 1.4bar or more with these is asking for trouble

 

it was an 03 sti in the report

 

*shrugs* wishes he bought an EVO *shrugs*

 

I'm running 1.5bar on non-forged pistons and all is well.

Surely this will depend on the mapping? Whats the biggest cause of piston failure? Det?


Bob

 

he doesnt say but i presume so yeah

 

the STI7 pistons are very strong as far as im aware, and as was mentionned earlier, STI8 onwards are not so good.....only slightly (if anything) better than their WRX counterparts. I was running 1.4bar on WRX pistons with no issue at all.

1.5 should be ok on an STI but as bob says its all in the mapping, 1.5 shouldnt be an issue though. I cant speak for older cars.

The odd thing is that it works the opposite way round for the cranks....the STI7 crank is weaker than the STI8>

 

Hypereutectics just seem to fail because they feel like it

Other than that Det is the killer, eating it's way through the edge of the piston to the rings or just causing them to hole combined with excesive heat