swisstonihasher

Hi chaps,

If I was to get a 2.5 JDM big port with AVCS, what would the cam profile be compared to 2L wrx heads with piper 285 cams? I've got a 2.5 already

Also, would you recommend arp head bolts set and obviously decent head gaskets?

I have ecu and wiring that can run AVCS already but dont have the heads yet. Anyone else done this before and what was the cost for fitting approx?

MOTORS S GT

iTrader: (2)

No such thing as 2.5 JDM big port heads.

swisstonihasher

Really? So what head options do you have for the 2.5?

MOTORS S GT

iTrader: (2)

You can fit 2.0 JDM big port heads, with combustion chamber mod to suit the 99.5mm bore, or just fit 2.5 STI or WRX heads & port, unless your going over 500 bhp the std heads flow enough.

merlin24

iTrader: (1)

As above - the "small port" heads have very good port velocity.

Mick

swisstonihasher

I've got wrx heads with piper 285 cams and adjustments so they fit the bigger bore, they're bloody lumpy upto 2,400 and that's part of the reason why I was thinking of changing but I know the ports have been machined and polished and the cam flows alot and now I'm starting to wonder if I'll gain or lose from using AVCS heads. Need to think about it more, thanks for the info.

swisstonihasher

What cams do the 2.5 sti avcs use? 264s?

s5ooob

iTrader: (1)

I have V5 heads on my 2.5, that have been mildly ported, then fitted with V5 group N high lift cams by Tegsport during a fantastic long engine rebuild that they did recently for me....

I think the cams are 270s iirc

Fitted with a relatively old style turbo, a td06 SL2 20g, and superbly mapped by Steve Simpson it produces 414bhp and 478lb/ft on Vpower.

More to come in the new year with a map for 20% meths, and an increase in the i/c to throttle body pipework, up from 50mm to 70mm, as Steve felt we had a breathing restriction in this area.

The engine revs as urgently and cleanly as any 2litre i've had previously and that torque hit is someting else in my anorexic type R.

JTinnovations

iTrader: (2)

My 2.5 uses 2005 JDM STi heads ("big port") with modified chambers, and the standard 2.0l JDM cams, with AVCS, and an LM480 twin-entry turbo. Not lumpy, very drivable, full boost by about 3800 rpm, and 525bhp

I was advised not to bother with different cams unless I was looking for high 500's.