what sort of bhp increase could i expect for £2500 on my classic wrx.

 

Depends..
Shop around for parts and do the work yourself, up to 350bhp.
Give someone £2500 and your be lucky to see 300.

 

depending on the year of classic, a power fc fitted and mapped for around £800, full decat exhaust including downpipe, approx £500, bigger injectors 550cc about £300, uprated pump and regulator about £180. Factor in a few hundred quid for a td05 turbo (unless you have one already)That leaves a bit of money for your brakes.recommended.

Obviously figures are ball park if you shop around you can get the bits cheaper, obviously fitting things yourself will keep costs down. (downpipe is an easy job - imagine a turbo wouldnt be much harder)

That should see over 300bhp easy, but the way the car drives it will feel like more.