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thanx for that VHR32, awsome site. but i dont know any of teh following values.

head is rb25det VVT out of r33.

Enter Bore/Stroke Designation Type

2 = Millimeters =2

Enter Cylinder Bore Size =86.5mm

Enter Piston Stroke Length =85mm

Enter Head Gasket Bore Diameter =87mm

Enter Compressed Head Gasket Thickness =1.5mm

Enter Combustion Chamber Volume In CCs =RB25=62.5cc

Enter Piston Dome Volume In CCs Negative For Dished Pistons (Use '-') = ?? RB30E = -0.97cc dish ??

= 7.6:1

EDIT: This was worked out with a RB30E bottom end in mind because you posted it in the RB30DET thread, not your RB25 engine.

Edited by VHR32
RB25 gasket if you have a R33 RB25 VCT head.

RB26 or RB30 gasket if you have R32 RB25 or RB26 head

cubes and i are running an rb25 cometic gasket with our r32 rb25de heads....

I wish there was a sticky or document with all the right info on this shit, to stop ppl asking the same damn questions and others giving half answers....

OH WAIT :) - CUBES HAS A GUIDE

cubes and i are running an rb25 cometic gasket with our r32 rb25de heads....

I wish there was a sticky or document with all the right info on this shit, to stop ppl asking the same damn questions and others giving half answers....

OH WAIT :D - CUBES HAS A GUIDE

ok, I added the RB25 gasket. I thought the others would be more common and cheaper to use so I left it out...

I put in 86.5, 85, 87 HG bore, 1.2 HG height, 65cc for RB26 (was a guess, some say they are 70cc? although CP measured some at 64.5cc avg) and 13cc dome.

= 9.12

Im picking up my RB26 head later today so i'll have to measure the cc's!

I have seen RB26 combustion chambers vary between 63.8 cc's and 64.7 cc's. So 64.5 cc's is OK for a rough calculation, but you should carefully measure the actual head and each combustion chamber.

:ninja: Cheers :yes:

A little update on AM-Performances GTS4 RB30DET.

Made 270rwkw.

http://www.skylinesaustralia.com/forums/in...t&p=2671762

Needs valve springs done.

The plenum has widened up the power band noticeably even on 8psi where it made a lowly 182-188rwkw.

A little update on AM-Performances GTS4 RB30DET.

Made 270rwkw.

http://www.skylinesaustralia.com/forums/in...t&p=2671762

Needs valve springs done.

The plenum has widened up the power band noticeably even on 8psi where it made a lowly 182-188rwkw.

well this shows that something is seriously not right with my car if he could make that power on less boost with the same cams! :P I'm depressed now!

well this shows that something is seriously not right with my car if he could make that power on less boost with the same cams! :P I'm depressed now!

Ash.. unsure if you read the whole post in the dyno thread but a peak of 256rwkw was seen on 15psi.

A little more boost and and tidying up of afr's and ign saw 270rwkw. And no adj. cam gears.

Forget the exh. manifold. The plenum is what definitely appears to open up the top end. Then as Shaun said you hit 300-330rwkw on the stock exh. manifold and you then 'need' to go aftermarket.

So for the price of my pistons and rods i could have had one of these motors ready to slot into my car ... fark im silly for being so stubborn with regards to wanting to be different :D

Can still be done Troy! :P

Head down to the wreckers and invest a hundred or two in a good second hand rb30.

I bought my bottom end that came out of a running car that was still in great condition (had been arse ended) for $150.

yes short runners.

I think the slight drop in mid range is probably the almost 2psi drop that was seen with the new plenum.

Prior boost was almost 10psi then tailed off to 8. After the plenum it sat on a steady 8psi through out. Not sure why it was playing about prior.

Interestingly there was no noticeable drop in off boost low rpm torque.

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