GTS-t RB25DET - what turbo for 300bhp

[MEL]

I have done a search but to be honest i havent got the first clue about different turbo specs etc and what is suitable for the job

I want to take the stag to a "stage 1" tune which i have started working on. The exhaust is halfway there, it will be given a full service over the next few weeks, hopefully an uprated pump is coming my way, i am getting colder grade plugs fitted, induction is being sorted (but opinions on the best kit are also appreciated). I think i will be seeking out Rising Sun for the remap side of things and laying out for a Gizzmo boost controller because i have heard good things about them.

Anyway back to the original point of this thread - what turbo do i need for 300bhp and where can i get it from I have just got a quote for rebuilding the standard unit with steel internals and roller bearings but want to see if i can get a whole new turbo for less as i cant really have the car off the road for the length of time a rebuild will require.

[Jay]

Standard one should see you fine, or an R34GTT item, think it`s SLIGHTLY bigger, a few on here for sale I think, try Mendoza`s parts for sale thread. About £150 IIRC

[MEL]

Standard one should see you fine, or an R34GTT item, think it`s SLIGHTLY bigger, a few on here for sale I think, try Mendoza`s parts for sale thread. About £150 IIRC

Does the 34gtt tubby have ceramic blades?

[Moff]

Standard one should see you fine, or an R34GTT item, think it`s SLIGHTLY bigger, a few on here for sale I think, try Mendoza`s parts for sale thread. About £150 IIRC

Depends if we are talking ATH or Flywheel power..

Standard turbo will have no probs blowing to 300 Fly, but will need cams to get it over 300 ATH (talking about a safe map)

[Moff]

hmmm, its an Auto... Bit more power loss, may struggle to get 300 ATH, but not sure

[MEL]

Depends if we are talking ATH or Flywheel power..

Standard turbo will have no probs blowing to 300 Fly, but will need cams to get it over 300 ATH (talking about a safe map)

Going to be sensible to keep the gearbox happy and go for atf. £150 to see 300 non stressed horses is much better than the near £1000 for a rebuild and to be honest who doesnt want a bigger turbo (even if it is only slightly )

What sort of boost is seen with 300bhp on a standard turbo?

[julio2906]

Does the 34gtt tubby have ceramic blades?

Yes the standard GTT one does have ceramic blades,and it is a bit bigger.
(and if you want one I have one for sale)

[MEL]

Yes the standard GTT one does have ceramic blades,and it is a bit bigger.
(and if you want one I have one for sale)

Whats the safe boost level on that?

[julio2906]

It was running at .85 and I never had a problem with it,im fairly sure it could go up abit more,not sure how much though.

[Squeak]

0.85 Bar max on GTS-t / GTT turbos, any higher and it's a case of risking it really..

you dont want the turbo over heating or melting those ceramic / nylon blades

[Moff]

Going to be sensible to keep the gearbox happy and go for atf. £150 to see 300 non stressed horses is much better than the near £1000 for a rebuild and to be honest who doesnt want a bigger turbo (even if it is only slightly )

What sort of boost is seen with 300bhp on a standard turbo?

Basing the answers on Manual Skylines, and a Power FC.

Dr Evil and I have the same spec (different branded parts) :

FMIC, Elbow, Downpipe, Induction kit, PFC, de-cat, exhuast, boost controller, with the only difference being I have CAM pulleys and HKS Camshafts, he has Z32AFM and 1.5mm HG (also a full head rebuild if that makes a difference).

I made 311 ATH with 297 lb/tf. Boost controller set at 0.80, but peak power was made at 0.7 and boost tailed off after 5500 revs due to turbo.

Dr Evil 275 ATH @262lb/ft and 0.85 boost

Hope that helps

[Squeak]

Every engine is different though and will make the power it makes. Only thing with when you start modding is you put more stress on other parts of the engine. Hence why rebuilds can help (fresh engine not 15 years old) or are eventually needed from all the extra strain of mods.

[Moff]

Every engine is different though and will make the power it makes. Only thing with when you start modding is you put more stress on other parts of the engine. Hence why rebuilds can help (fresh engine not 15 years old) or are eventually needed from all the extra strain of mods.

Mine is still ok... for now

Due to the weigh of the Stagea, Cams would help due to the extra torque

[Bubble]

It was running at .85 and I never had a problem with it,im fairly sure it could go up abit more,not sure how much though.

That is the reccommended safe boost limit. I did try my standard one at 1.0bar for a very short time, but it didn't seem to go any better, so I reduced it back to 0.85bar

It is not so much the increased boost that will make a standard turbo fail, but the extra heat generated.

[Andy W]

i'd suggest your was that much higer as maybe the diff ratio wasn't changed

Dr Evil had a head rebuild and a metal gasket fitted as the car had been overheating due to a split / blocked rad

the cams won't make that much difference at all,

the stagea power figures are only 230 hp to start with, combine that with an auto box and 4wd trans and you'd be looking at quite a big loss