gt 30 dyno results

[Cubes]

Steve,

My thoughts exactly, what made me think there was a restriction some where in the exhaust is the way the curve flattens out in the top end on the high boost setting.

The power curve can be influenced by the ramp rate a little, but it still looks a little slow getting on to decent boost.

As discopotato once said with this dyno graph... Pumping losses.

[Bl4cK32]

my exhaust is only a 3"

not a jap style dragged one either

i really need a 3.5" or better yet a 4"

wont happen on my car though... no room.

thats where split systems (2x 2.5" pipes) come in handy

[Cubes]

thats where split systems (2x 2.5" pipes) come in handy

hehe they don't work to well when they are sitting inside the house though.

[Bl4cK32]

all in good time I may be waiting to fit it with the GT35r yet.....tee hee

[Spoolup]

I have RB25det with gt30/40 , 0.82 ex housing with external gate, got 395 rwhp on 22 psi. It starts making boost around 2900 rpm and full boost around 3800 rpm.

It is extremely drivable and will melt the tyres in third if I go the boot.

[R31Nismoid]

how can yours fry the tyres, when mine makes the same power and everything, 200rpm later is the only difference and i have not one problem with traction. ??

[Cubes]

Different Tyres (maybe worn and slippery), suspension?

[Robo's]

how can yours fry the tyres, when mine makes the same power and everything, 200rpm later is the only difference and i have not one problem with traction. ??

Judging by your nick, youve got a R31. Maybe they have a softer independant rear end than the 33 or much stickier tyres The 33 is slippery, even i get sideways movement in second once i come on boost with a 2530. Count yourself lucky you dont have these issues. First gear is useless. Ive converted back to stock suspension to get some more grip.

[Spoolup]

I also have an r31, but built a Rb30/25 for an R33. It had similar power and would also arc up in third and it had 255 rears.

If I plant my foot in third gear it will spin into all the way into fourth on a smooth bitumen surface.

[marco]

my gtst has a gt35 turbo with 0.63 housing running 255rwkw @ 15psi. its a bit laggy full

boost is at about 4300rpm

[Sydneykid]

how can yours fry the tyres, when mine makes the same power and everything, 200rpm later is the only difference and i have not one problem with traction. ??

HICAS, too high rear spring rate, poor suspension geometry, too stiff/poorly valved rear shocks, worn sub frame bushes, too high tyre pressure......etc

[Spoolup]

or just alot of power in a street car :-)

[R31Nismoid]

Judging by your nick, youve got a R31.  Maybe they have a softer independant rear end than the 33 or much stickier tyres The 33 is slippery, even i get sideways movement in second once i come on boost with a 2530.  Count yourself lucky you dont have these issues.  First gear is useless.  Ive converted back to stock suspension to get some more grip.

first gear is fine, unless im saveage on a launch. If i am smooth then its totally fine unless im nasty with 1st/2nd gear change then its skating

My rear end is more prone too loose traction than an R33 due to the primative design of the R31 IRS

Ask any coupe owner than tries to get grip, its a mission due too squat and the sheer camber that ends up on the rear causes around 2/3 of the tyre to actually touch the road.

And im only running 245's on the rear, just cheap sumitomo's that in my opinion are very average. Thats on 18's too...

I agree with you SK, some of these guys cars must be shockingly setup as i wouldnt even say my setup is anywhere near what i could be.

still, im at a loss :headspin:

[Robo's]

first gear is fine, unless im saveage on a launch. If i am smooth then its totally fine unless im nasty with 1st/2nd gear change then its skating

My rear end is more prone too loose traction than an R33 due to the primative design of the R31 IRS

Ask any coupe owner than tries to get grip, its a mission due too squat and the sheer camber that ends up on the rear causes around 2/3 of the tyre to actually touch the road.

And im only running 245's on the rear, just cheap sumitomo's that in my opinion are very average. Thats on 18's too...

I agree with you SK, some of these guys cars must be shockingly setup as i wouldnt even say my setup is anywhere near what i could be.

still, im at a loss    :headspin:

Maybe you dont have the power you think you have then. What Sumitomos you running, im running the HRZ 11, 255/40/17.

[Steve]

So many variables. I spent alot of time and money setting up my skyline so it didnt do crazy things.

R31 - non IRS too isnt it? IRS has its own challenges. Just being non IRS and no HICAS would give a car massive advantages until you sorted the issues in a car that is equipped with IRS and HICAS.

Making the power is only half the job IMHO.

[Steve]

Sorry forgot to add, just because two cars make the same peak power, run the same boost and come onto boost around the same rpm, doesnt mean they have the same power over the rev range.

Car A at 1 bar may be making 250rwkw @ 4000rpm, car B may only be making 180rwkw at the same rpm and boost. Both may make 300rwkw peak power. The shape of the curve makes a big difference too.

[Spoolup]

Mine is IRS and only 235's. So that says alot.

Setting up the old style IRS on HR31's to keep reasonable chamber angles under hard acceleration is near impossible.

[R31Nismoid]

So many variables. I spent alot of time and money setting up my skyline so it didnt do crazy things.    

R31 - non IRS too isnt it?  IRS has its own challenges.  Just being non IRS and no HICAS would give a car massive advantages until you sorted the issues in a car that is equipped with IRS and HICAS.

Making the power is only half the job IMHO.

HR31 has IRS and HICAS

HICAS i still retain, and all of it is very primative.

And i have 270rwkw, there is no doubt about it. Rolls off Race Pace Dyno as such

See what it makes next weekend @ AutoSalon...

[Cubes]

What diff ratio does the HR31's run?

-------

Throw the scanned dyno plots up..

Lets see the mid range and how they both ramp up on boost.

[R31Nismoid]

either 4.11 or 4.4

not sure what mine is, i suspect 4.4