i was thinking about either a 2.5 rs or a wrx.

the 2.5 has the bigger engine, which seems like there can be more possibilities...that is, if the block can handle boost like a wrx.
(which i doubt without major block work). the lower price of the 2.5 is a huge factor.

can someone give me differences in pistons, connecting rods etc? for the 2 engines? which one has the weaker components...all that.

suspension...what are the differences between the two models?
how are the springs/struts?

brakes - both have 4 wheel disc correct? difference in calipers?
vented rotors? not cross drilled cause i heard they warp too easily right?

shift box and transmission - how are the syncros? good? bad? too small? etc. if anyone has gear ratios plz reply with them.

differential - i do not want open differential. which car has lsd? do they both?

drivetrain loss, power @ wheels? anyone got the figures for both cars? also any 1/4 stock times?

clutch - good? bad? pedal play?

 

WRX is turbo'd. It's designed to be a turbo, so is the better base for building real power.
The 2.5 is designed to be normally aspirated, so has high compression, not good for a turbo upgrade (and yeah, I know dozens have done it, but knock is a real issue). You need to decide what you want...turbo or n/a. The .5 displacement difference doesn't mean squat between these two engines.