Jump to content
SAU Community

GTT or GTS25t ser.1/2 turbo

B0oStEr

By B0oStEr,
in Engines & Forced Induction

 Share

Recommended Posts

R31 POWER Mentor

R31 POWER

Posted
Posted

Well

Series 1 R33 turbo has normal compresser wheel and ceramic exhaust wheel.

Series 2 R33 turbo has nylon/plastic compresser wheel and ceramic exhaust wheel.

R34 GTT turbo is same as above but it might have different guts.

dojobi Experienced

dojobi

Posted
Posted

I'm not so sure the turbo is the reason it makes 206kW, Joel. They've got cams with more lift (from memory) and continuous VVT as opposed to the stepped VVT on the R33. Having said that, I have no idea whether the turbo was actually changed :). I just reckon there are enough differences to explain the extra power.

Cubes Grand Master

Cubes

Posted
Posted

I've heard of them failing on stock boost when they hit the track.

I think turbo's failing (ceramic) has more to do with Exhaust Gas Temp's than anything else.

Pressure probably has a little bit to do with it..

I'll let you know if it is when I get the RB20t turbo cranked up on the RB30DET.

It looks like its going to make at stock boost (11psi) what it made on the rb20det at 1bar. (164rwkw)

I'll dig up this thread if it pops when I try to push a little more boost through it. :)

dojobi Experienced

dojobi

Posted
Posted

Yeah on the track your EGT can certainly get up there and stay up there. My gauge was showing 1100 degrees when I was on the track once. I have no idea where the temp probe was for it though or if that is a high/low reading but it definitely hot enough to kill a turbo I reckon.

An RB20 turbo on an RB30DET will be insane btw. That'll be on boost the second you touch the accelerator.

One other thing - because you have 50% more displacement now, does that mean that the turbo has to flow 50% more air to get the same boost level? So running the same boost will actually be working the turbo harder?

Cubes Grand Master

Cubes

Posted
Posted
An RB20 turbo on an RB30DET will be insane btw. That'll be on boost the second you touch the accelerator.

One other thing - because you have 50% more displacement now, does that mean that the turbo has to flow 50% more air to get the same boost level? So running the same boost will actually be working the turbo harder?

It sounds strange as you let out the clutch and you hear the turbo begin to whistle away before you have even started accelerating... :)

Its not really related to the displacement but more so the head.

The head is what allows air in to the pots and what essentially creates the restriction that creates the measure of pressure.

As the RB25 inlet valves overall are 10mm bigger they obviously allow a higher flow of air before pressure is required to force the air in.

I have noticed with the rb25 that as soon as it makes like 1psi you can feel the extra power. With the RB20 it required around 4-5psi before you really felt anything.

But yer.. the turbo will be spinning harder at a lower psi when bolted on to the rb25 head compared to the rb20t.

This is why Rb20t' need so much boost to make decent power. They have small valves and really look it when you put them side by side to the rb25 valves.

R34GTX Rising Star

R34GTX

Posted
Posted

For the noobs like me out there, what's the tell-tale sign of a failed turbo other than the obvious no boost??

I'd like to know why the GTT turbos fail so often.

Is the failure in the nylon impeller?

It's easy to see how high EGT could transfer heat via the shaft, to melt the nylon impeller.

JAPCAB Proficient

JAPCAB

Posted
Posted

You can always check the turbo for shaft play - this is movement in the shaft of the turbo. You can do this quite easily - remove the intake piping, and then remove the intake pipe going onto the turbo. Check for movement in and out, and side to side. Other tell tale signs can include the turbo being noisy - making loud drilling/spooling noises (we all know a stock turbo shouldnt do this) hitting boost but not being able to hold boost. With the R33 gts-t turbos, they wont last long if run at higher boost levels. With the R34 GTT there seems to be a string of people experiencing turbos failing at .7 bar so probably a good idea to look at replacing the turbo if wanting to run more than stock boost as the standard turbo's dont stand up to that much abuse. Its better to replace the turbo for say $1500 rather than blowing the turbine and risking damaging the engine.

For the noobs like me out there, what's the tell-tale sign of a failed turbo other than the obvious no boost??
Abo Bob Grand Master

Abo Bob

Posted
Posted

I read everything R34 and I don't know where you people are getting this idea that the GTT turbo's are crapping themselves left right and centre.

The ones that I have heard of failing have been the exhaust wheel delaminating and 'ending up in the cat'.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Kinkstaah
      Boost cut after swap(RB25DET NEO) R34

      By Kinkstaah · Posted

      Stock ECU (or more accurately stock tune) absolutely refuses to go over 10psi and behaves like you have seen. The Nistune is the same if it is the stock tune. If the Nistune chip has been tuned, the resulting tune could be literally anything for any combination of parts. The Nistune just makes the stock ECU Tunable.
    • Kapr
      Boost cut after swap(RB25DET NEO) R34

      By Kapr · Posted

      So stock ECU does not like anything above 10 psi?  That Nistune one is just for "try" if it will be any different, I know it need to be tune for that. I know but YOU may know about these problem but i/we dont. They few little Skylines here let alone people who know anything about tham so that is why iam asking here  
    • Duncan
      V37 Radiator removal

      By Duncan · Posted

      So now we have a radiator with no attachments whatsoever. It lifts up with a particularly tight spot between the drivers side air box mount and the lower radiator outlet, but if you've got this far you will sort that too. This is the lower mounts with the rad out so you can see where the rubber bushes go, it is a straight shot upwards Done! Assembly is the reverse of disassembly, with blood less likely to be shed.
    • Duncan
      V37 Radiator removal

      By Duncan · Posted

      Right, onto the second last trick. The Air Con condenser is mounted to the front of the radiator and stays in the car when the radiator is removed. There are 2x 10mm headed self tappers holding the top of the condenser to the radiator, remove those The bottom of the condenser is attached to the radiator with clips. You need to lift the condenser out of those clips and clear (up, then forward). f**ked if  could work out how to do that last bit with the front bumper on. I hope you can, and you share the trick.  Bumper removal probably deserves its own thread one day once I've recovered the will to live, but basically you need to remove the wheels, front inner guard liners (clips and 10mm headed bolts), the self tapper between the guard and the bumper at the rearmost point of the bumper (same as an R32 that bit), any remaining clips at the top/front of the grill, an absolute bastard design with a plate that holds the top of the bumper above the headlight each side (only 1 bolt which is tricky to get to, but the plate catches 2 places on the bumper and must be removed....carefully!) and push clips between the bumper and guard under the headlight. If you've done all that you will be faced with wiring for the fog lights on both sides and in ADM Q50 RS at least, 4 nasty tight plugs on the driver's side for the ADAS stuff. So, the clips at the bottom look like this on drivers side (looking from the front) And on the passenger side (also from the front), you can see this one is already out Clearance on both of these are super tight; the condenser needs to move up but the upper rad support mount prevents that, and the radiator can't move down far because it is (rubber) mounted. Once you achieve the impossible and drop the condenser off those mounts so it does not stop the rad moving, you are good to go
    • Duncan
      V37 Radiator removal

      By Duncan · Posted

      OK, next the shroud needs to come off and there are a couple of tricks. Firstly, there is a loom from near the passenger side headlight to the fans, coolant temp sensor etc and there is no plug to undo.  In my case I was OK to leave the shroud on top of the engine so I just undid the passenger side fan plug and about 10 of the clips which gave enough free wire to put it aside. The fan plugs were super tight, the trick I used was a small falt screwdriver to push down on the release tab, then a larger flat screwdriver to lever the plug out of the fan unit....be careful with how much force you apply! If you need to remove the shroud altogether for some reason you will have to deal with all the plugs (tight) and clips (brittle)....good luck. I removed all of the clips and replaced them with cable ties that I will just cut next time. Also, in the Red Sport / 400R at least, the intake heat exchanger reservoir hose is bolted to the shroud in 2 places with 10mm headed bolts; so remove them (the hose stays in the car; no need to undo it at the t fittings down at the radiator lower mount. Once you've dealt with the HX hose and the wiring loom, there are 3x 10mm headed self tappers holding the top of the shroud to the radiator; remove those.   The shroud then lifts out of the bottom mounts where it sits on the radiator, up and onto the engine out of the way. Simples
×
×
  • Create New...