Rbon91

iTrader: (6)

As above how much difference is there in the 2? Do the jdm ones provide more power?
Just thinking as im goimg to start sourcing parts over the next 12months or so to do a build get heads ported and polished etc

cheers ryan

stonejedi

iTrader: (51)

JDM AVCS heads are big port more flow and a better base to start from if you are gasfowing port and polishing etc....,start looking from now as they don't usually crop up that frequent and make sure you inspect them for signs of damage I.e cracks etc usually around the spark plug region,I looked for a good set for so long that I eventually brought some new for my engine project.SJ.

jayallen

iTrader: (31)

EDIT.....I was talking ****

Its bizarre that newage JDM WRX's and JDM STI's had the same heads per model year.

Part numbers.
http://forums.nasioc.com/forums/showthread.php?t=823167

trails

iTrader: (41)

think it's just the Spec C heads that have a bigger inlet port...

tubbytommy

iTrader: (20)

is this another jdm myth like the stronger bottom end in newage jdm cars despite also having the same part no.

JTinnovations

iTrader: (2)

Heads are the same for a given MY STi AFAIK, but the cams vary between UK and JDM. For example - IIRC - a JDM MY05 STi has the same heads as UK MY05 STi (and the same as a Spec C JDM) but the cams are different (although, again, cams are the same for JDM STi and Spec C).

trails

iTrader: (41)

Sounds like the most cost effective option for Subaru so probably correct

Any news on testing those longer charge temp sensors Tim?

JTinnovations

iTrader: (2)

Hmmm...still waiting on the samples with the correct thread: I'll chase them up

trails

iTrader: (41)

thank you

stonejedi

iTrader: (51)

My mistake your right,it was kind of early and I was still half asleepSJ.

jura11

iTrader: (7)

Agree on this,we run JDM WRX Heads on our wagon previously which are Big port,just cams are there lazier than JDM cams(as Neil said they're very similar to the UK STI cams)

JDM WRX V7 onwards or STI are same,difference is only in the cams and shims I think


Jura

jura11

iTrader: (7)

Hi Tim

I'm not 100% sure,but we have few heads at home like UK STi or JDM and you can clearly see difference between the UK and JDM as above guys said,JDM heads have bigger inlet ports(all JDM have bigger inlet ports)

Jura

Rbon91

iTrader: (6)

So is it really worth spending a fortune on the JDM heads? Cheapest ones I can find are £1800... Can get uk ones for £400-£500 then ported and polished

Midlife......

iTrader: (2)

Paul at Finch Motorsport might have some suitable heads kicking about..

Shaun

hibbs

iTrader: (7)

I've got 2 engines here for sale, one from a uk sti saloon on a 52 plate covered 65k, one from a jdm sti wagon on an 02 plate covered 117km if anyone is after a complete lump, both run spot on

jura11

iTrader: (7)

£1800 is probably for new one,speak with breakers or try speak with Jap Performance Parts,they have at stock usually,price wise around £700

Just be careful 2.0L heads are known for cracking around the spark plugs,find perfect heads is sometimes very challenging,we are went via 4 pair of the heads,5th set has been in great condition and we are bought from JPP( Jap Performance Parts)

For used JDM Big port heads you should be looking at £400-£500(this highest price is for perfect heads in perfect condition)

About the other options,depends what engine you are thinking to run,if you are thinking to run 2.35L then 2.5L WRX or STI heads can be good option,if you are thinking to run 2.1L then Big port heads will be my choice like on 2.35L too

Jura

Rbon91

iTrader: (6)

Thanks jura.. 2.35 would be perfect but dont think I will be able to invest in that for a while

ryan