l70byb

Is there anyone that can help. looking to put a 2.5 litre bottom end in the scooby which is 93 wrx.Been told that the heads or maybe cam shafts aren't really up to the job . i'm looking for bout 400bhp out of it . so whats the best way ? any ideas ? are the heads are ok can i get away with just a set of cams if so what ones ?

TonyBurns

iTrader: (3)

First check your insurance, alot wont do 2.5 conversions or engine mods, but you would be better off with a full 2.5 engine.
Speak to John Banks, but you will be playing with a v2 2.5 and a v1 2ltr, they dont always match....

Tony

john banks

I've not fiddled with Phase I heads and an EJ257, but I have heard that non-STi heads do not seem to work well for good ignition timing or high power. That said, I think you could probably reach 400 BHP with octane booster with a 20G with an exhaust and uprated intercooling. You need to find out the right headgasket to use to get the right compression ratio - 8 to 8.7 seems to be the range favoured by most, might be better nearer to 8 with the WRX heads to help the detonation resistance.

V5-APS

iTrader: (1)

Speak to David at APi Engines.....he'll be able to help.

ZEN Performance

the heads will be fine, it's more a case of what you want to acheive with the overall setup.

Why couldn't this discussion stay in your original thread?

Paul

l70byb

I was told to put a thread on general as well

Scooby50WRX

For myself, I have supplied a 2.5 l block to fit on a '01 WRX and the gasket to use is a 1.1 mm. No timing problems measured after a ECU remapping.
As John said, a strong turbo have to be choosed to use this 2.5 L.

megrac

Early wrx heads ver 1-4 have a small 45cc combustion chamber.
I have ver3 sti heads with the ej257, i've used the 2.5 na gaskets witch are 1.4mm or 1.6mm thick which i think gives about 8.4:1. Poeple said to me that my valve timing would be off using the thicker gaskets but the factory ver3 gasket is the same thickness.
For me anyway 400hp comes at about 1.3bar with my setup tuned on bp96.

M0NEY

I had standard 95 wrx heads with my 2.5 (std internals) and the car was pretty damn quick. Never got readings from it but it deffo felt more than my old 2.0 (which was pushing 380bhp).

I have hand my heads ported and polished heavily now and was speaking to Bob Rawle about cam set up. Will be changing cams soon but thats cause i want more power.

As said on your other thread, if you want 400bhp, you can do this with 2.0