sti ecu on wrx
 

is it possile/safe and advisable to switch from a wrx to a stil ecu from the same year (classic)

What MY do you have first?

you have a 95wrx iirc so technically yes but i tried this with my 93wrx (putting a 6K ecu into it) and it brought the MAP sensor error code BUTi do believe a few people are running them with no problem

yeah, 95 wrx. so the MAP sensor would have to be changed? to a 3 port? is the MAF sensor compatible. would it need mapping? cause wrx have 380cc injectors dont they? and stis 440cc?

no you dont need to change anything apart from the ecu, assuming you have a tdo5 turbo, as the turbo and the intercooler were the only external differences between the early v1/2 imprezas,
so if your car is a saloon wrx and still has the original tdo5 fittted (many come from japan with what ever turbo they can find fitted) the ecu would be a straight fit.

ah cool... it's actually a wagon, so got a TD04 atm, but turbo needs replacing so gonna go for TD05.

was gonna go down the ESL remap route, but that's £500 min, STI ecu sems better value

yes thats right, replace turbo with tdo5 run on sti/z4 ecu then you are laughing.