Experience With A 25/30 And A "small" Turbo

[joeyjoejoejuniorshabadoo]

hey guys,

i'm looking to alter my setup and gain some torque and response.... i'm happy with the power, as i dont want to be breaking things regularly if possible

i'm open to all sorts of ideas but at the moment i'm leaning towards a RIPS 25/30 long motor

i'm planning to use my current turbo (HKS 2835 pro s)

what i was wondering is if anyone has any experience on how a "small" turbo like this performs on a 3.0

does it creep much? does it surge? etc etc

for comparison's sake it's basically a garret 3071 with a .68 rear housing

cheers

[Adriano]

I had an rb30/25 NEO with a mildly highflowed r33 turbo, it made 170rwkw @7psi, held boost fine, torquey, but tapered off really fast. You mey find that you end up making the 300rwkw you want at 4500rpm, and 270rwkw at 6000, which is about 1/2 the torque as 4500

[N1GTR]

You know who to speak to; Al.

He was kind enough to hand over the keys a few times at a deca a while ago. It's a true freak of a car to drive in its own special way. If I had a gtst, I'd get the same setup and some seriously grippy tyres

[joeyjoejoejuniorshabadoo]

yeah al's is awesome, but i'm using a sliiiightly smaller turbo again

he's on a 3076 .86

[Dale FZ1]

Adriano is on the money. It would pull like a tractor down low, build boost fast and then torque would taper quickly as rpm rose. Turbine spec is too small to let it breathe up high, could not produce over the same rpm range as Al.

[KiwiRS4T]

Ask Duncan. He has an RB30 in his Stagea with a relatively small turbo on it and he's quite happy with it. As he says its not a race car its just to tow his race cars.

[joeyjoejoejuniorshabadoo]

i fear you guys might be on the ball here...

think i might sell the 2835 and buy a 3076 .86

[JonnoHR31]

try it first and see, aslong as your not expecting a massive increase in power it should do the job fine

[BoostdR]

R33 high flow, 270rwkw and full boost before 2500rpm. It does surge a little.

[joeyjoejoejuniorshabadoo]

i think i could probably pick up a new 3076 .86 for around the price i can sell my 2835 kit for...

might as well go for the best possible setup for what i want, as opposed to settling

considering the difference will only be a few $$$ and the turbo has to come off anyway

[Harey]

R33 high flow, 270rwkw and full boost before 2500rpm. It does surge a little.

Is that a GCG hiflow with completely standard exterior?

[Harey]

i think i could probably pick up a new 3076 .86 for around the price i can sell my 2835 kit for...

might as well go for the best possible setup for what i want, as opposed to settling

considering the difference will only be a few $$$ and the turbo has to come off anyway

I think you mean 0.82 housing. To be honest I think the 0.82 will be worth changing to. Exactly right the turbo is already off and you will get good money for your current kit. Not to mention the hassle and expense of fitting the current turbo up getting a tune and then deciding its not what you want and having to change turbo again and retune.

[R31Nismoid]

i think i could probably pick up a new 3076 .86 for around the price i can sell my 2835 kit for...

might as well go for the best possible setup for what i want, as opposed to settling

considering the difference will only be a few $$$ and the turbo has to come off anyway

Spot on and what you should be doin

[conan7772]

3.0 + poncams + 3076R =

But if you want the most out of it, Disco is right.

Go the 1.06 rear and 650 cc or larger inj.

[Dose Pipe Sutututu]

3.0 + poncams + 3076R =

But if you want the most out of it, Disco is right.

Go the 1.06 rear and 650 cc or larger inj.

I just looked at your boost response, looks great, seems as though it beads off pretty quick.. I'm guessing because of the small housing!

So many hybrid motors don't see full boost till close to 4500+ rpm..

I'm also planning to build a 25/30 motor, with VCT running for my next car (whenever that comes)..

[TiTAN]

I just looked at your boost response, looks great, seems as though it beads off pretty quick.. I'm guessing because of the small housing!

So many hybrid motors don't see full boost till close to 4500+ rpm..

I'm also planning to build a 25/30 motor, with VCT running for my next car (whenever that comes)..

they must be running big turbos for 4500+.

my GT35 (0.82 rear ext gate) can pump 18-19psi @ 3600ish

[Amoreuxi]

For a streeter.

Going much smaller than a GT30 and you need to look out for the old torque vs rpm vs gearing.

The RB30's choke very quickly with a small turbo and begin hurting over 5500rpm of which seriously kills your acceleration once up and rolling.

If the rpm doesn't match the gearing you'll find you will be shifting considerably earlier and the old rb25/20 setup was quicker and importantly more fun to drive.

GT30 .8 - 2800-3000rpm all its boost

GT35 .8 - 3500rpm ish all its boost

GT35 1.06- 3800-3900rpm all its boost.

Don't let that gt35 1.06 300rpmish fool you the 1.06 does feel a fair bit more dull to the .8 in first and second. The .8 makes more boost at a lower rpm where as the 1.06 tends to making very little then snap on hard. In my experience anyway.

Edited January 21, 2011 by Amoreuxi

[R31Nismoid]

There is also on/off throttle to contend with.

Not only is a larger housing more "dull", it's also going to be slower in/out of gears to rebuild boost and so on.

Also making it easier to bring back up onto boost and just feather it. Given Hamish's use of car, the smaller housing is certainly more suited

[Harey]

There is also on/off throttle to contend with.

Not only is a larger housing more "dull", it's also going to be slower in/out of gears to rebuild boost and so on.

Also making it easier to bring back up onto boost and just feather it. Given Hamish's use of car, the smaller housing is certainly more suited

Not sure if "dull" is the correct word to use. The 1.06 housing will have some lag and then hit harder.

I would personally choose a GT35 0.82 for an RB25/30 if I ever do one.