been asked this question by lad down the road, wot is the max boost a 1994 wrx can handel?, i have a 1993 running at 18psi he is going down the same route as me simtec ecu fmic etc, but for some reason wonts more boost than me , said i presume 18/20 psi is as mines mapped to that.

 

I suppose really it depends on the set up.

 

he has same as me standard cd engine.

 

To be honest it's a slightly moot question. Given how old these cars are, probably the only person who can give you an accurate answer as to how hard these will still go is the person mapping them.

 

Steve, the gearbox will probably give up before the engine hence why I mapped yours reasonably sensible from a boost point of view.