What one 2.0L 16ecu (02-05 WRX) needs to hit 4XX whp on a MUSTANG dyno:
So this is an answer to the question...just one of many I am sure because teeing off into this and coupled with a couple other FAQ's that need to be read in order to work for someone else is a must. I don't have dyno numbers until I went to a full build, just because I found it a waste to dyno a car with such mild upgrades, and open-source was going to fit more MY kind of driving. Again this is different for everyone.
I staged my progress into a 4xx whp build, just simply because after transferring from the American Muscle realm into subies, is a whole different ball game. Aside from basic engine functionality, the two worlds are so different that the "which is better?" argument is invalid in my eyes.
First was just a cat-less exhaust, panel filter, "canned" tune, and upgraded fuel pump (a MUST for anyone looking to modify their whip).
Second was out of necessity rather than need. And ended up being cheaper for me. A relative had run my WRX with no oil in it for quite some time. And upon checking it, after getting it back I promptly filled it. Quite annoyed at that. Nevertheless, the damage was done and the engine seized at the worst time on my way to work. Time for 2.5L build!!
So it was a OEM spec. EJ257 shortblock with matched heads (ported to match). I trashed the TD04 and put on a VF22, DW650cc injectors, STi TMIC, open exhaust, and an open source road tune (STi Mikey FTW!).
Third was a more radical upgrade. Blouch 1.5XT-R, DW850cc inj., FMS TMIC, JDM Ver. 6 TGVs (deleted), KSTech 73mm intake, 3" Agency Power hard inlet, Ver. 8 JDM STi 6spd full swap w/brembos and R180 rear end, Invidia Q300, Megan catless downpipe, Invidia uppipe. Dyno'ed at EFI logics 327hp/310tq -as you can see these upgrades are a pretty penny as Unabomber points out on his FAQ for a Mustang dyno, and STILL not hitting 400hp as one might on a dynapack. HEED that warning kids! I was limited by the TMIC, and stock MAF maxed @ 4.75v. The 16bit ECU is becoming a bit of a dinosaur, and tuners more and more are rolling their eyes at having to deal with it.
Up next and still in the planning stages are: Kelford cams 272/272 (high lift/high duration), 1mm oversized (37mm/33mm)Supertech valves (standard length), FMIC, EWG, speed density from Cobb, and possibly a bigger turbo. All told this will cost upwards around $4-5k for parts, labor, and tuning. This will net me 4xxhp more than likely. If not, then full twin-scroll rotated and I can add another $4k to that.
Set a goal and be willing to fork out the $$! And if you're married, don't count on staying married for long LOL!