gt 30 dyno results

[Steve]

Sorry if you thought I was implying you werent making the power - 270kw isnt enough to really start doubting people about unless of course its in a Hyundai:)

out of interest (means alot more than just peak power) what sort of power are you making at 3000rpm, 3500rpm, 4000rpm, ........ 7000rpm (or wherever you have redline) The spread of power speaks volumes about a cars performance.

Also, what wheel alignment specs are you running?

[R31Nismoid]

ill get a printout of the old dyno graph.

wont be till next weekend though.

Then ill try post it

that'll make it easier than me speculating as i cant remember

[masTers]

Considering running the GT30 with .63 on my RB30-DET, anyone know how this might go?

Very interested.

[Wazz]

i'd imagine almost lagless if twins.. that'd be interesting

[R31Nismoid]

Considering running the GT30 with .63 on my RB30-DET, anyone know how this might go?

Very interested.

interesting too see what its like up top and if it can flow enough.

a .82 or a 1.06 would be my choice

[discopotato03]

If you wanted OEM type performance , ie 4 - 6 pounds of boost no doubt a GT30R could do it . To do this you would probably need a rather large waste gate to prevent exhaust restriction . Always remember that when looking for higher boost levels (waste gate shut) marginally sized turbines can form a restriction for exhaust flow . With your example the 63ARR turbine housing is painfully small for a three litre blowing into a GT30 turbine . I try to look at what the manufacturers do - they have many millions to spend on R and D . I see the XR6T as a good example , the GT35R is perfect for a low performance (boost) four litre but note its housings choise . Its turbine housing is the largest of the three sizes available while the compressor cover is the smallest ratio (of three) and a family size down on what GT40 compressors generally use . I believe Ford was looking for absolute minimum exhaust restriction (large 1.06 ARR turbine housing) and not very high airflow rates to enhance a large capacity engine .

For most of us Nissan fans we're looking at three litres and a more sporting breed of transport ! The same principles apply though the variation's are less weight and a smaller airpump (donk) . If it were me I'd use the largest available turbine housing for that GT30R and the port shrouded .60 ARR comp cover they normally come with . Even this with a large gate and lowish boost is really only suitable for a low rev ceiling engine but thats good enough for some especially on the street .

Cheers A .

[bigcarl]

im running stock cams, 3inch exhaust , maybe they are restricting it a bit. because its pulling 229 rwkws at 13psi and only another 31 rwkws at 20psi???

[RS500]

im running stock cams, 3inch exhaust , maybe they are restricting it a bit. because its pulling 229 rwkws at 13psi and only another 31 rwkws at 20psi???

bigcarl,

i believe that when a turbo is in it's highest efficiency island and that there is no exhaust restriction, the power increase per psi should be about ~10rwhp (7rwkw), so you should be making a bit more power on 20psi.

which GT30 core is it and what exhaust housing r u running?

[bigcarl]

500hp compressor. a/r70 comp front cover and a/r 64 rear housing. good info thanx rs500. just found out today the max boost the standard nissan head gasket can take, ive blown my head gasket running 20 psi/ 22psi. does anyone know where and how much i can pick up a tomei after markey head gasket for??? would lowering the compression ratio help make my engine last a little longer before rebuilding?

[bigcarl]

does anyone know how thick the stock headgasket is? what comp ratios does tomei head gaskets 1.2mm , 1.5mm give on a standard engine?

[Steve]

Not sure about tomei, but if you check the greenline site, I believe it give detail of CR

I had a HKS 1.6mm, gave a 8.6:1 CR. I did this because I was advised by a jap that it was best when pushing the stock internal RB to around 300rwkw and a bit beyond. According to him (and other sources) it is not uncommon to make 300+ with stock internals in Japan as long as you decompress. JMS also did this with their GTSt, and it lasted well even with Denzo thrashing it

Also, this jap guy recommended keeping boost around 1.2bar for hard thrashing on the track, but said it was ok to run 1.7+ for drag or dyno, just not prolonged caining. (tune permitting of course )

make of it what you will, but my engine has survived without rebuild.

[Sydneykid]

1. does anyone know how thick the stock headgasket is?

2. what comp ratios does tomei head gaskets 1.2mm

3. 1.5mm give on a standard engine?

1. 1.0 mm

2. 8.8 to 1

3. 8.5 to 1

Combustion chamber volumes do vary, so treat the above as a guide only.

[Skyrine-Dave]

why spend $600 on a Tomei head gasket when you can get a very similar multi layer composite metal head gasket from Cometec for a fraction of the price

[Bl4cK32]

why spend $600 on a Tomei head gasket when you can get a very similar multi layer composite metal head gasket from Cometec for a fraction of the price

thats what I was told when building my engine...cant remember the price exaclty of the Cometic, but its a hell of a lot cheaper than the Jap brand gaskets around. Its a 3 layer metal head gasket with like an inbuilt o-ring setup. Apparently they use em on diesel engines, and in Group A?? dont know if its true or not....

[OFENSV]

thats what I was told when building my engine...cant remember the price exaclty of the Cometic, but its a hell of a lot cheaper than the Jap brand gaskets around. Its a 3 layer metal head gasket with like an inbuilt o-ring setup. Apparently they use em on diesel engines, and in Group A?? dont know if its true or not....

i bought one of these for my rb30det and the price was around $300

[masTers]

OFENSV did u still have to o-ring the block? and can you give me the part # and contact detials?

[OFENSV]

no there is no need to o'ring the block with one of theese head gaskets. i have to see if i still have the part number, its an rb30 head gasket not rb25. i got it through the people that did the machine work to the block so not sure where they got it from.

[masTers]

Thanks mate, if you can let me know that would be pro.

[bigcarl]

thanks very much for the info sk, steve and ofensv. where is cometec located?

[OFENSV]

www.cometic.com