2.5 short block swap

[kreitz3]

Hey guys (Paris).

First off, I have a mostly stock 2002 WRX.

I am getting a 2.5L short block out of an RS with the stock RS pistons. It needs an oil pump, crank needs machined, and new main bearings. Other than that it's ready to go.

I would like to run this block with the stock (2.5 RS) pistons to get the torque down low and turn my boost down a to about 6-8 psi so I don't blow the heads off the thing.

Would this be the way to go, and if so what else do I need to do. If this is not the way to go, should I get the STi pistons?

I DD this car and it is also my RallyX car. I am sick of the thing bogging in 2nd gear and I can't always leave it in first.

What would DI.com do?

[sebhockey]

I dunno about going with STI pistons, but WRX pistons from a 06/07 would be good along with STI rods. Of course if you can get some forged pistons with the same compression as the stock RS I would go with those if you want low end torque.

[BlackParis]

Sounds like you want to complicate the problem :D

What turbo are you running now? stock td-o4 ?

I assume you mean by (bogging) that your not in the boost, and the 2.0 has little torque to begin with... However I think I read somewhere that with NO boost on the ej20, it makes ~ 178hp and 160 trq... where as an ej25 sohc is 165hp 164trq at their cranks...

So basicly what I am saying is look into a smaller turbo :D If you like the upper end look into a possible twin turbo setup... And Cams can also make a HUGE difference on HP and TRQ, if you know what to look for....

I love how you addressed it to me.... I Gaurentee someone else can throw some insight on building the 2.5/2.0 hybrid ( L&E Fab ) ...

About the rebuild: I would just recomend getting an EJ257 shortblock cause it works, and works well, in just about every application... Screw rebuilding and machining a crappy block.... Unless you really want to for education purposes, but the ej257 Block is stronger, internals are srtonger.....

Either way it should be fun and whatever you do.. TAKE PICTURES!!!!

[L and E Fab.com]

I love how you addressed it to me.... I Gaurentee someone else can throw some insight on building the 2.5/2.0 hybrid ( L&E Fab ) ...

About the rebuild: I would just recomend getting an EJ257 shortblock cause it works, and works well, in just about every application... Screw rebuilding and machining a crappy block.... Unless you really want to for education purposes, but the ej257 Block is stronger, internals are srtonger.....

Buy the EJ257 block unless you are going to replace every part in the block with something stronger then what subaru puts in any of there blocks, this counts STI bits. I am talking full COBB, Crawford, or Cosworth (any one ever notice that they all start with C's) also I think that using the N/a block is a mistake. I don't know why but I do.

Unless you are shooting for super high boost or high compression you don't need stronger then the stock EJ257 block.

I am running just shy of 300 whp with 320 ft/lbs. on stock wrx internals.

It will be cheaper to buy the EJ257 then to buy all the parts and machine the n/a block.

Fun Project if you have the tools but could end up being a terrible waist of money.