Hi guys, my first post on scoobynet so here goes. I have a GC8 Impreza with a 2.35L motor. I currently have some V4 STI heads on but i need more flow. I was after some advise and recommendations as to what to go for. I have looked at the Cosworth heads that are avilible but am unshure as to wethere they are worth the money and i did not real want to change my intake manifold and engine management at this time, I am how ever open to all surgestions and arguments for having them.

Thanks in advance Craig

 

I thought STi 3/4 heads could do 500bhp?!

Or are you wanting more than that anyway?

 

They do 500bhp but i need more mate.

 

Christ, now you're asking.

Speak to Paul at Zen, Dave at API, Alan/Martyn at Enginetuner, Mark at Lateral, harvey, WMS, etc...

Sorry, I've been of no help at all. The tw@t

Oh yeah, merlin24's hot on heads (if that don't sound too nutty :-D)

 

There are far cheaper options than the Cosworth heads, but it does depend on what your BHP aim is, and using what turbo ?

Switching to later heads, and good engine management will make your life much easier.


Mark.

 

Hi Mark, it's Craig Ellsmore. You know my spec and i am going for one of your ECU's but not shure at what stage to do it because of funds. For any one els it is a GT40-88 twin scroll.

 

Work in progress

 

You need a siren on your car warning parents to hold on to their kids, or that turbo will hoover them. Impressive

Not had any first hand experience of these people, but plan to use them on my rebuild. All CNC machined, so it should be an accurate copy of the flow tested original:

CNC Heads - HOME

Anders

 

2No Fuel feeds?

Explain how this is plumbed up? I am guessing feed into each rail then return from each rail to a T then into FPR.

What pump/pumps are you using?

 

Hi Craig, didn't realise it was you.

I considered using CNC heads, but decided to go another route, due to their cost. My current set up breaths really well, but that will be in combination with the Cosworth intake manifold, and the cams.

My 2.35lt / hybrid GT4094 was making peak power above 7600rpm !!!

 

As you guessed but using the fule reg as the T.

The pumps are the high flow high preshure Walbro's that Mark from Lateral surplys and they are in tank. The is a surge tank to be fitted on the next round of mods.

Mark tell me about it, once it's on boost it just pulls harder and harder. you can feel it hold back right at the top tho due to heads and maping to keep it safe. I have looked at the valve train Paul @ Zen offers to go straight into my V4 STI's but i figured the heads still go for good money in stock form so i do not mind starting from scrach.

 

redace, how much would you want for your STi 4 heads (if they're coming off)?

 

Craig how much power are you after? or do you just want the heads to continue breathing at the top end? with the same turbo?

Or are you going different turbo?

 

Looks a nice setup, but I am a bit confused. To me it looks as if your dump valve is in the turbo intake pipe or am I just missing something? Run 400 bhp on my bugeye so next step will be upto 500 so I always take a close look when people speak about getting to that level and beyond.

Opps seen what I missed it is the pipe for the recirculating air. Doh

 

We have used Ric in the past and were very happy with the service and results.

 

I think they will be coming off but it will not be for about 2 months, as for price will see what the market is like for them at th time.

i would like to make a nice 600bhp on V power if i can and stay with this gt40-88 for the moment. the is space to fit some think bigger but do not think the will be the need for it. car is running 2.2bar at the moment and the ignition timing has been pulled back to 16 degreesat the top end because that is all it will do on those heads.

lol


Thanks Martyn, i will give them a call and see what they can do for me.

 

Yeah sure redace no hurry whatsoever.

 

Another pic

 

I am no expert by any means but but would it not be worth looking to do something with your current heads ? My heads are V4 also, flowed and a set of DH22 cams and they have made 581 to date on a 2.35. That was a 2.0 bar running V-Power and 20% meth on a 35R 0.82.

Since then I have added Solaris and more boost but no RR figs as yet but it feels quicker still !

I also know of another car near identical spec to mine (engine and heads) that has made circa 550 on the same turbo.

 

So if i went for porting my V4 heads and did a cam change you think that would be up to the job? i did like the idea of changing the valves for S/S and inconel especial if i can get 1mm over. my V4 heads are shim over bucket and i would also like to change that to shim on top of the valve so the is no chance of them coming out.

Just a quick pic of my Hyperflow monster cooler, i can not say enough good things about this bit of kit.

 

Cool. i've got a Hyperflow to fit to my 1993 WRX and it has a similar sized core.

Redace, do you know if the fog covers can still be put back on okay? - it's just that it looks like the endtanks get in the way (can't really see properly).

 

My valves have been done too. Speak to Mark or Paul @ Zen chap but it must be an option

 

Shim over buckets would make these WRX buckets. I would seriously reccommend going shimless buckets from a newer scoob, as at high revs you wouldn't want to lose a shim and possibly some 272 cams that'll get it all breathing.

I'm actually quite surprised that the WRX shim over buckets that your currently using are coping with your current setup and haven't popped out at high revvage....

Will be interesting to find out what option you actually go for in the end.

 

check out the heads on this site Slowboy Racing, Inc. i have used them in the past for pistons etc.

 

STI Baly sorry mate my mistake, they are shim under bucket.


mikef04 Thanks for the link i will have a look and see what they offer.

 

joz8968 i do not know mate because i had fog's in there not just covers. it dose look like covers would go back in TBH

 

Redace/Joz how much did you pay for your intercoolers?

 

Here you go Baly...

http://cgi.ebay.co.uk/ws/eBayISAPI.d...fvi%3D1&_rdc=1



Not bad, considering these babies are c.£1k new!

 

Thanks.

It does look like they'll go back on. Whatever, I'll soon know lol...

 

No pics mate but they do go on with a very small amount of trimming.