RB30DET turbo choices

[drunkenmaster]

After a long a tiring read through that never ended RB30 thread up top, I thought I'd ask my questions directly as I have heard there are a few knowledgable people on this board when it comes to RB's and turbos.

I have an RB30DET freshly rebuilt using standard internals and 8.3:1 compression.

I hope to acheive 250rwkw at 15psi or below as well as have a streetable responsive car i.e. not too much of a laggy feel.

Am i asking too much?

At the moment I am choosing a turbo and the GT30 with the 0.82 exhaust A/R seems to be the go.

The motor is not going in a skyline though, rather a 1000kg or less 260Z so there are some concerns that the 0.82 will come on boost too violently for the light chassis. This has lead a few people to suggest the 1.06 exhaust AR.

Having spent more than a lot of new cars these days on this project and not really being close to finished, I am trying to kerb my spending and am playing with the idea of running an internal gate and using the standard exhaust manifold. With this in mind I have seen a mock up of the XR6 turbo for sale.

This is a GT3540 running and enlarged internal wastegate in a 1.06 AR exhaust housing. Will this be too big for my application and will the internal gate really hamper things too much?

Thanks guys

[R31Nismoid]

GT30 would be the go on a 3lt bottom end, AND a twin cam head.

It'll be nice and responsive with the .82 thats for sure.

i wouldnt for see the need for a 1.06

What is you motor been built to redline at?

[skids]

mate have you tried:

http://www.calaisturbo.com.au/

Regards

Luke

[JNR24]

.82 is too small small for a VL, yet for a 260z!

last 2 VLs i have put GT35/40s on with .82, ended up changing to a 1.06 with 1 month of road driving.

.82 are fun, but boost comes on too hard to quick. (again this comes down to the application of the car, .82 would be good for circuit work.)

[drunkenmaster]

Nice information

Any opinions on internal gates?

calaisturbo.com has a few threads similar to this with only one epxerienced opinion also leaning toward 1.06 ex AR.

What about GT30 vs GT3540 arguments?

[Steve]

If you are only after 250rwkw, perhaps a GT30 will be too big.

Go the GT35R, dont be weak:D

[JNR24]

Steve,

The GT35R, R = Rebuildable/Repairable??

Theres no diffrence between a GT35 or a GT35R it terms of size. (both have same size compressor & Exhaust housing,/ can have same size housings fitted .63, .82, 1.06.)

Heres the confusing part:

The GT35R's flow 50lbs/ as per GCGs website (www.gcg.com.au) and are rated @ 700HP

BUT the GT35's flow 60lbs/ as per HPIAB (www.http://www.horsepowerinabox.com/HPIAB2/prod34.htm) and are rated @ 600HP

Whats the 100HP & $655.50 diffrence between these turbos? trim sizes? core?

(sorry about the hijack)

Cheers,

Trev

[Guest INASNT]

Nice information

Any opinions on internal gates?

calaisturbo.com has a few threads similar to this with only one epxerienced opinion also leaning toward 1.06 ex AR.

What about GT30 vs GT3540 arguments?

Dude y have u gone with an internal wastegate with your setup???

A nice turbo like that needs a nice 45mm external gate to get the full potential out of it.

[Skyrine-Dave]

Hye Trev,

The 'R' just means ball bearing in garretts definition... The lack of an 'R' is more than likely just lazyness rather than anything significant.

Dont go by GCG's site. Check out ray halls site he a more comprehensive specs page.

also the 700hp rating is for the top spec GT35R.. ie the 1.06 exh housing

[JNR24]

hi dave!

got a suprise for you coming soon... (Check screenie below)

I thought "GT" was Garrets definition of a Ball Bearing unit. e.g

GT35R = Ball bearing Garret, Repairable

T04R= Bush Bearing, Repairable

Someone has to know, i checked Rays site but i couldnt find GT specs...

Cheers,

Trev

[GTR-Ben]

I have a .82 GT3040 for my RB30DET with a GTR head. 42mm external gate. Be interesting to see how it acts..

[JNR24]

hi dave!

got a suprise for you coming soon...      (Check screenie below)

I thought "GT" was Garrets definition of a Ball Bearing unit. e.g

GT35R = Ball bearing Garret, Repairable

T04R=  Bush Bearing, Repairable

Someone has to know, i checked Rays site but i couldnt find GT specs...

Cheers,

Trev

Woops forgot to attach screenie:

[Guest INASNT]

I have a 0.82 GT3040 on my RB25DET with stock internals and 45mm ext gate and it acts perfectly

[Skyrine-Dave]

Ok copy from Ray Halls site:

Order is:

Model: Part#: CHRA#: AR: Trim: Model: diam: HP: lbs flow: AR: Trim: diam

GT35 714568-0001 706451-0005 0.70 56 GT40 2.41/3.22 700 60 1.06 84 2.45/2.68 

GT35 714568-0002 706451-0005 0.70 56 GT40 2.41/3.22 620 60 0.83 84 2.45/2.68 

GT35 714568-0003 706451-0005 0.70 56 GT40 2.41/3.22 550 60 0.63 84 2.45/2.68

Pretty decent listing there

[GTR-Ben]

I have a 0.82 GT3040 on my RB25DET with stock internals and 45mm ext gate and it acts perfectly

Yeah when does boost hit? how much boost do you run and what HP does it make?

Stock intake mani etc for you?

[Skyrine-Dave]

Trev,

Screenie makes me a happy kid.. when do you expect to get them and send them out??

[JNR24]

Dave,

Well it arrived at aussie customs yesturday, so as soon as they send the package out to me il send em out. You SHOULD have it within this week (Fingures crossed that there is no more delays)

Cheers,

Trev

[Skyrine-Dave]

Happy days

Back on topic... ... GT35R's seems to be nice turbos suited for an RB30DET

[drunkenmaster]

GT35 = GT35

GT35R = GT3540 as far as i know.

There is a lot of bad feeling towards going internally gated, what is the reason?

Another question and probably the most important is when these larger GT's make full boost and how suddenly?

[Skyrine-Dave]

please just open the garrett catalogue and look at the damn definitions

The "R" Denotes the 'rolling' element found in garrett single cartridge, dual ball bearing hi performance turbos.

GT35/40 is another naming convention made up by suppliers which has been discussed in the R33 RB30 conversion thread... Why bother arguing, just look up the catalogue and match it to what you are buying.

Internal gate is 'bad' as it wont be as effective at controlling boost as an external larger diameter wastegate would be... Sure you could do it if you really wanted to, but you would benefit from using these turbos the way they are meant to be run.. with custom manifolds and external wastegates