Found some Hypereutectic pistons not that expensive!

[raist60]

The point i was trying to add about the T04s is the in-efficiency of the old style turbo wheels. Ie. More heat from comp wheel.

[Cubes]

Thats true..

had any one thought about the possibility that the reason why we can run so much boost and power with the standard internals compared to the VL's is that the RB20/25/26 motors have oil squirters?

[raist60]

Dont think so, VLs can run make some pretty cool power on their standard internals.

Oil squirters just cool the base of the piston... dont think that would make a big difference.

[Cubes]

RB25DET's have been known to make 300rwkw providing the tuning is good nothing usually lets go.

[JNR24]

My mates VL running T88, 22PSI all day on stock N/A bottem end.

Spent over $800 in tuning, but it is possable.

[T0nyGTSt]

Hey so installing these pistons is no go???

Check this:

RB30E

Bore - 86mm

Stroke - 85.0mm

Capacity - 2962 cc

Compression ratio - 9.0:1

RB30ET

Compression ratio - 7.8:1

Pretty severe.

T.

[Cubes]

So it all still comes down to Tuning....

So the Standard Pistons are good then. Just like Sydneykid said...

RB30DET with NA RB30E pistons = ~8.2:1cr

[lowlux]

hey joel ill see if i can get a few sets through work as i can get N/A pistons with chromeoly rings for $350 LOL

not bad huh

[Skyrine-Dave]

$350 with rings !!!

god damn thats alright

[Cubes]

I was looking at a R32 GTR Today ...............

I want one.. I was driving home seriously considering how I could slap this block in it ...

[Steve]

lowlux, for $350 a set, you can put me down for some too please:D - maybe we could organise a group buy if there is enough interest - or at least Joel and I could split postage.

[Cubes]

Sounds good... I'm going to start looking in to how a RB30 bottom end bolts in to a R32 GTR.

I'm tired of 2wd no traction.

I am probably dreaming still as my budget is max 25k. All the GTR's around here I have seen are 35k. And even then the one down on Anzac Highway (Silver One) has had a few bingles as the gaps etc don't line up and the under body has been freshly painted. Some thing just didn't look right with it.

[Xeron]

Ive said this before in previous threads. If u get hyper pistons, i sure as hell hope u dont drive in summer, cause a just a few seconds of ping and u can blow a hole in em. And hey there also alot more likely to ping too due to the higher silica content refecting more heat into the combustion chamber.

Cheap

Fast

Reliable

Pick any 2.

[Steve]

lowlux, are those $350 pistons stock ones or the hyperwhatsashitbagger stuff?

[Skyrine-Dave]

i agree... group buy

pick any 2

i want fast and reliable, on the cheap

can stock NA cast pistons only hold 15psi with 8.3:1 compression ?

[T0nyGTSt]

At this rate, you may as well buy stock GT-R pistons... you might even mix in GT-R conrods and crank if you wish...

T.

[Sydneykid]

Hi guys, Its pretty simple really, an RB30 being a 2 valve engine does not flow as well as RB20/25/26's with their 4 valve heads. So to make decent power they have to run a lot of boost, rule of thumb 5 to 6 psi more to make the same power. Such high boost requires lower compression ratios, rule of thumb 0.5 lower for the same power.

My experience, comparing compression ratios for 2 and 4 valve heads is a waste of time. On the flow bench we typically see 30% more flow out of 4 valve heads with similar capacity.

Hope that adds to the discussion.

[Sydneykid]

Hi Joel wait until next year, when 1989 GTR's qualify under the 15 year old rule. Very cheap then, no compliance costs.

[GTS20X]

Another thing with Hypereutectic pistons is they tend to shatter rather than just break or crack ring lands like cast or forged pistons. Also some forged pistons also have a high silicone content so be careful if your thinking of running Nitrous.