Hello,

 

I recently bought a 2003 Subaru Impreza TS 2.5 L. I was thinking of turning her into a beast but realizing that I'm stuck due to the SOHC. Is there a possibility of using DOHC engine in replacement? If yes, what would you recommend? I rather build the engine for me to fully understand the engine instead of having someone doing it for me. Also, any recommendations on what else I could do to my car? I can spend up to 10000. Maybe, 12000 depending on what need to be done. I know i could sell the car for a sti or wrx but I rather drive a sleeper.

I'm sure others would give better detail. But with that budget id get my hands on a nice EJ257 (STI engine). Get a ECM or aftermarket one and use that. Going to be the quickest way to have a lot more HP.

No sense messing with a NA engine when you'll never be able to compete with an EJ257 that's also built.

Where do you recommend to go find EJ257? But then I rather look have a complete forged piston, crankshafts, etc., to increase the capacity instead of being restricted.

wiring is the hard part

 

need a stand alone engine management system

 

custom wiring harness stripped and built to marry to your vehicle

 

need to be mindful of immobilizer set ups which limit swaps. 

 

engines - google them.  you need to determine what you want first:  bare subaru block, used or new, short block, long block, used block, used engine...and which one times each of those variables. there's quite a few options. 

Welcome. I love the sleeper idea. If you want a swap Contact rally sport direct, they do wiring merges. Not a hard swap really, but buy a link stand alone. Bolt ons can net 350whp which is enough to run with some vettes. 10k might get you done nut that's tight, not possible if you are paying for labor. Get a 6 speed sti swap version 8 or later. 5 speed are junk as at 350whp they snap crack and pop. Figure $6500 for version 8 engine, trans diff axles and harness, add 1k for maintenance,(timing belt oil pump new filters plugs etc) $850 I was quoted for my GC wagon wiring, $1300 for ecu and $600 dyno tune time. That's gonna get you started