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I have 0.63 GT35R (ext gated) and it is on boost by 3200rpm.... no idea on full boost yet as the wastegate was leaking before I took the car off the rd to replace the ecu with something better. Stock internals, but every piece of supporting bolt ons in place with the exception of my poncams..... forged internals on standby :worship:

R33 S1 - RB25DET

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I have 0.63 GT35R (ext gated) and it is on boost by 3200rpm.... no idea on full boost yet as the wastegate was leaking before I took the car off the rd to replace the ecu with something better. Stock internals, but every piece of supporting bolt ons in place with the exception of my poncams..... forged internals on standby :D

R33 S1 - RB25DET

Do someone of you guys have a GT35R with 0.63 housing and can tell when the full boost will be available on an RB25?

As i read out the 0.82 housing have full bost at 4500rpm with some poncams on an RB25.

Thanks in advance.

Edited by Behind Horizon
I have had the .63 housing on my neo rb25det and it made over 340rwkw and rpm was at 9000 full boost by 3200 thats was at 1.7bar ..now thats pretty responsive for a high mount

it sounded like a machine!!!!...hahaha

cheers

Are you sure that your GT35R can deliver power up to 9000rpm with a 0.63 housing ? :laughing-smiley-014:

I have had the .63 housing on my neo rb25det and it made over 340rwkw and rpm was at 9000 full boost by 3200 thats was at 1.7bar ..now thats pretty responsive for a high mount

it sounded like a machine!!!!...hahaha

cheers

Can you please post up a dyno graph?

More importantly of where 'full boost' is made, is where it makes all its boost when rolling on the throttle in second gear and or how it develops boost in first gear.

A good example of this is the difference between the GT30 .8, GT35 .8 and GT35 1.06 on the dohc 3ltr.

The 'full boost' difference between them on the dyno is marginal but on the road there is a HUGE difference as to how they drive. The GT30 feels like a supercharger with strong linear power from idle where as the GT35 (in the lower gears I'm talking) feels a little laggy laggy then bang your off.

Interestingly they both made the same power on basically the same boost.

For comparisons sake the GT35r .6 turbine map flows very close but slightly better to that of the GT30r .8 combination.

The GT35 1.06 that I've seen makes all its boost around 3900rpm so marginally higher than the GT35 .82 yet on the road the difference in spool is unbelievable. Its as if the smaller housing starts making some boost and providing the windmill affect at a considerably lower rpm where as the 1.06 comes on in a rush within a few hundred rpm.

I'd really like to see the comparison in spool and drive ability between the GT3040r .82 and the GT35r .6. My guess is they would be 'fairly' close.

So in short; a dyno sheet making x psi at 4500rpm doesn't tell the whole story of how it performs on the road when taking off from a stand still then rolling on the throttle or accelerating out of that low speed second gear corner.

Are the GT3040r and GT30r different? I Always assumed one has a different front housing..

This thread is interesting as I will be putting my GT3040r on in the future and like to see back to back results with similar turbos.

Cheers

Yeah there's a few different variants of the GT30 with the 60mm turbine wheel.

GT3071

GT3076 (old school .7 comp 7blade compressor)

GT3076 (HKS3037S style .6 comp cover 6 blade compressor)

GT3040 (gt35r 82mm compwheel .7 comp cover)

so what would you recommend, gt35r .63, .86 or gt3040 .86, i'd really want a hks 3037 kit but they are too expensive, the car isn't used for drifting or anything, its just a daily street car and sometimes used at the drags which is why i thought the .86 gt35r would be a good option as it wouldn't run out of puff up top as i thought the .63 would, but if the .086 doesn't come on full boost until over 4500 it wouldn't be efficient as i can only rev to 7000 because its still a stock bottom end, say for example rolling in 2nd gear with a gt35r 0.86 at about 3000rpm, how long would it take to get up and go if i put my foot down, would it feel like a gutless NA car below 4500?

1.7bar = 25psi.

So whats the secret infected flow? How did you get it making 25psi at 3200rpm when every one else isn't able to get even a GT30 making that boost at 3200rpm.

So given 25psi at 3200rpm.. That would have to be 18psi by 2900rpm??? Sounds technically impossible from the 2.5ltr unless its ramp rate was mega slow ... as I said on the brake.

Not having a dig. Just trying to work out how you managed to beat the laws of physics. So tell us how you managed it. :)

I like lots of brutal quick spool and mid range that makes the driver work so I'm not the one to comment. :)

On pump fuel with std cams the .6 appears to make around 270rwkwish. Do cams you can pick up 30rwkw ish push more boost in to it and you should be able to crack 300rwkw.

Sure some are able to keep raming boost in on pump fuel which does make more power but its not good for longevity especially if you want it to hang together at the local track.

So in saying run out of puff up top.. Really no such thing it just doesn't make as much power as easy.

The .82 no doubts help with getting it to hook up and allows power to be made easier but to really make use of it a set of cams and extended rev limit would be nice. But realistically as long as it makes all its boost at 4k 3-3.5 thousand rpm band is ok.

The rb20t blokes work with less. :)

the 0.82 makes around 300rwkw on around 1 bar doesn't it, u saying the 0.63 would make 270rwkw with same boost, i got around 240rwkw now and getting kinda bored of it so i think i'll be going with the 0.86, dou you think it would be better low mounted or high mounted

Depends on the dyno and the car.

I haven't known one to make 300rwkw on 1bar BUT I was told I will get close with a set of reasonable cams (265's).

IF you run a nice exhaust manifold, nice inlet, free exhaust with big cams u can make 300rwkw on around that boost. But its not as simple as just dropping a .82 on and it will make that power on 1bar.

A good example is sky30. Std inlet, std exhaust manifold gt35 managed 312rwkw on 18psi roughly. tried cams didn't help with peak power due to what I suspect is the end of the run for the std exhaust manifold.

Did big cams in an rb26 head with its std short runner plenum and a nice exhaust manifold. Power jumped to 382rwkw on ~17-18psi.

Making the motor breathe better via nice cams, inlet and exhaust manifold modifications is a must if you want to run big numbers on low boost.

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