Heey guys,

I am bussy building my project but now i was wondering what heads will be better? I dont mind intake manifolds. Can make them work but which heads are better? I know the v3 sti heads are more aggresive but the v5 sti heads are better flown.

Which one will have more benefits? For spoolup etc. Or would that not matter?

What is you advice on this one.

Btw i am going to run this :
Vf37 with RCM headers
Wiseco pistons
pauter rods
2.5L crank
powerflow exhaust
acl bearings

sorry for bad english but i am from holland.

 

Nobody?

 

V3 heads are the ones to go for, excellent straight from factory to support over 500 bhp.

 

V4 heads will also do the job as well

So go for V3/V4 heads over the V5/V6 heads

 

And think about adding a Harvey up-pipe, available from AS Performance, for better, earlier, spool.

 

Is there castings marks on them, so you spot the version 3 and 4 ones ?

 

I have had the same head since birth and am still an ugly *******

 

but on a serious note I was about to say that v3 / 4 heads are both capable.

the spec you have listed is pretty impressive - what kind of power are you hoping to achieve? Bear in mind anything worth having does not come straight from a factory - it will want fettling

 

V3 sti heads are the best to go with, if you can find some. They have the best cams, more aggressive and higher redline.
V4 sti are very simlar but with slightly less aggressiveness compared to v3 but not much in it.

My mate prefers the v3 over v4.

 

my engine is a v5 sti and it spools rapidly but im only the 300 or slightly over figure

 

Sti Version 3~4 share a common head casting with the WRX of that year range.

The casting numbers are LH-B and RH-B.

You need to check the valve codes, EH + IH (which are the same as the Type R), shim type ( under bucket or over bucket ) spring colour and length and finally the all important lines through the camshaft letters to identify a genuine set of STi heads.

Mick

 

I'm under the impression the manifold/wiring is different as well between the v3-v4 and v5-v6? E.g. I was advised that I could only use the v5-v6 heads on my wrx project

 

Correct, you have to mate a v1-2 inlet manifold I believe for v3-4 heads but I stand corrected

 

Has that ever been proved though?
I have never seen any evidence that the cams are any less agressive in V4 heads than they are in V3 heads
Everyone always mentions V3 heads as they were around first.

Merlin Mick...you probably seen more of these than most. Have you ever seen a difference in the cams?

 

Inlet manifolds and wiring looms are all different
There are three types
V1/V2
V3/V4
V5/V6

The quickest way to ID what is what is to spot the location of where the coil packs are located, as they are in a different position on all three inlet manifolds.

Unless you are doing a bare shell up build and getting fancy with making your own custom looms. As a rule do not mix and match

 

It's been a few years since I've had to degree the standard STi Version 3 ~ 4 cams in for M.O.P, but as far as I can recall, there is no difference in lift or duration between them.
Same cams are used in the 22B.

Mick

 

for the mild difference between the 2x styles use the heads that MATCH you inlet manifold and ECU/loom........

 

Thanks Mick
People always bang on about V3s but that seems to confirm my understanding that there is no difference between them

 

I have no experience in either, but obviously you just read or hear the stories and think Hmmm.
It was you and merlin that identified my heads when I asked so I can only take this information on board