Hi. I have a 96 import wrx sti v2 impreza which is currently running 0.9 bar boost (12.7 psi) as standard. The engine is in really good condition nothing at all wrong, few tiny mods such as performance filter and dump valve etc. Have sports cat downpipe and box.

My question is this, given its the sti engine how much extra boost could i run without the need for further modification. I am however thinkin of getting a better top mounted intercooler.

 

anything up to 1.3-1.4 bar on standard internals shouldn't cause a problem with your setup. you should see power upto 315 bhp ish on stock turbo maybe a tad more with your other mods. however few things depend on what boost to run by how you plan on getting the extra pressure ie chip/remap/manual boost controler. i think im rite in presuming that 96 ecu's can't be remapped so if you are goin down the chip/boost controler route, id be very carefull of running any extra boost due to fueling issues etc. Only way to get the power safe is aftermarket ecu, and remap from a reputable mapper. car will be totaly different and safe. hope that helps.

 

thanks i though about 1.3 bar, was planning on getting adjustable boost controller and fuel pressure regulator rather than a new ecu at this stage. the injectors seem pretty big. Should this be ok? not planning on using it on the track.

 

the size is irrelevant. if its underfuelling or need more timing the only way to correct that is via a remap which will require a new ecu. its the only safe way. a fuel regulator will just even things out, not correct a fueling issue if there is one. sti injectors are 440cc which will be big enough for the mods your running if you had the map with the stock turbo.track use doesn't make a diff, if its running lean which will prob be the case it will be lean weather on the road track or where ever. IMO best to be safe than sorry. £500 quid for a second habd ecu or even a new one is far better than a new engine!!

 

DOn't forget the fuel cut limit on these ecus as it won't allow you to just raise boost over 1.1 bar without either a remap or FCD.

 

STI injectors on the 96 version are 380cc not 440cc

Cannot run 1.4bar on the standard map sensor as 1.2 is the max iirc