sti in a wrx
 

Hi all i have a 95 wrx with a dead engine. A sti v4 lump has come up for sale localy and i would like to know if it will it bolt in and run ok on a standard map if i use the wrx injectors???

:thumb:

Has just the bottom end failed e.g. a big end bearing? 'Cause if so, then the "no hassle" route would be to use the STi v.4's fully assembled block and whack that onto your existing top-end/looms/ECU, etc.

If you replace the STi v.4 motor in wholesale i.e. the whole long engine, then you're in a whole world of pain trying to hook up the electrics, breathers, etc., etc....

That said, it would be nice to use the STi v.4 heads (they can flow around 500bhp!, - should you want to get into serious modding later on ;)). Your exisiting IM will bolt straight to the STi v.4 heads and I believe you can still retain your 1995 "coils on plugs" ignition system, too....

Also, if you wanted to replace your top-entry turbo for a later front-entry one (or chop off your existing one's snorkel), then you can fit the STi v.4 IM and intake pipe too! The intake goes under the IM for a more efficient, straight intake path. But you'd also need the MY97-00/v.3-6 PAS pump/pulley to make it fit.

BTW, if you go for a different turbo though, then you would have to get mapped, and therefore you'd need a a PFC, ESL or Simtek ECU, etc, etc.


Your best option - if you don't want to remap and have minimal labour/hassle, etc - is to just fit the STi v.4's assembled block only, thus retaining your 1995 WRX heads/IM/ancillaries, etc. If you fit the STi v.4 heads too, then you may have to do a remap, as they might affect the amount of air that goes into the engine (compared to the 1995 WRX ones). You'd also have to choose appropriate thickness HGs so as to mimic the CR of the 1995 WRX heads.

id say use a wrx bottom end as theres no point changing to semi forge pistons when everything else is standard

ok cheers ill have a think. If i get the sti motor would it be wise to put some new bigend and main bearings in there to refresh it but still use the old crank or is this a bad idea?

i wouldnt touch it, your bound to have wear over the years and you'll get clearance issues