hi all thinking of getting back in a subaru this year but need some spec on the above ie max power the std 2.5 wrx engine can take and gearbox diff's and rear diff the std turbo etc etc .. so all help would be good .. im in a evo 5 with 383.2 bhp but it's time for it to go, had it 2.5 year's . i need the same power or more ..

 

Go straight for the sti mate if u want that kind of power.. Getting a wrx to that power will be costly

 

Agreed. I have a WRX 2.5 2006 Hawkeye. Runs 220bhp as standard (although mine was making 253 standard). Can get them to 350bhp easily enough by changing a few bits and the standard TD04L turbo to a VF35, 43, 48 or TD05 or something similar but the gearbox, clutch, diffs, brakes etc are limited at this power level. You will end up spending a lot upgrading to 6 speed gearbox setup to go above that level safely.

The 2.5 pistons have potential failure problems above 1.35bar boost (350bhp ish depending on turbo) so may also need a forged engine to fun safely at 400bhp.

Other than that, great cars! Love mine to bits.

Buy an STI! (And thats coming from a WRX owner)!

 

is the wrx engine different to the sti engine???

 

Nope. practically the same, still got same piston failure problems on 2.5 engines. You can run 400bhp ok on standard 2.0 wrx/sti engine, but not 2.5 without going forged pistons & rods.

I personally love the torque from the 2.5 motor. Mine is running a safe 334bhp & 381 lb/ft torque. pulls great. My 5 speed WRX gearbox will be on borrowed time at this power though.

 

if i changed the pistons for forged one can the rods and crank take 400hp??

 

will the 2.0 sti engine go in ???

 

Just go for a late blobeye with wide track ,dccd and avcs should take around 450 without internal work

 

Yep can fit the 2.0 engine in but the 2.5 has other benefits. As Craig said, the late Blobeye shape before the Hawkeye 2006 came out has all the toys with the stronger 2 litre engine.

The crank on the 2.5 is pretty much bulletproof, so just pistons need changing for 400-450bhp really. May want to change the rods too just in case.