Hi all what does make the ej20 give up after the 350bhp mark? Is it the rods or the pistons? or the crank?Mine is a 93 wrx import and after doing hrs of research when going up above 350bhp it seems the engines go bang! If you dont forge them, Surly if the pistons carnet take it change them and leave the rods or the other way around! Reason I'm asking a mate of mine is strapping a turbo to his already quick eg civic b16a2, now for him to take his above 400bhp he has to change his pistons but not his rods as the rods will hold near 600bhp (in a 1.6��) yet our ej20's carnt take more than 350bhp????

 

Hi there

Its all together,if you are change only pistons,the yours rods will give up later on,not sure on the classic,but usually WRX rods will last 400bhp,then you will need have look on headstuds and better headgaskets etc.

If you are looking on later JDM STi engine(from 01 onwards/New age and they're too EJ20) they're usually are OK to run high 400bhp,some running nearly 500bhp without the problem and some running above 500bhp


Jura

 

On the classics it's the rods mostly, above 350, well not so much the rods but the bolts, and as they are pressed in I don't think it's possible to change them.

There is also a weakness in the gear boxes, mostly it's the casing that has a weak spot, but people do often strip gears on them too.

But to be fair most that let go are usually down to something fuel related, poor or no mapping, running lean, det, poor fuel quality and fuel starvation are the big killers, and it doesn't matter what rods and pistons you have in there when that happens most will throw a shell or melt a piston and cost some big bucks, ask me I have that particular designer T-shirt.

But make no mistake a true 350bhp classic IS a proper street weapon.