GTT or GTS25t ser.1/2 turbo

[B0oStEr]

Is there much difference between these three turbos as an RB20 upgrade?

[black_32]

well as far as i know the series 2 rb25 and rb25 neo r the same turbo i hve 1 on my rb20 and it goes really well but its was on there before i got it so i cant tell u how much diff it made

[Advan_01]

Series 2 turbo spools slighty faster than Series 1.

[R31 POWER]

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.

[Cillham]

is there a visual difference between the s1 and s2 r33 turbo? i ask for future reference when i start looking for one, and i want to know what one im buying if the seller doesnt know. when did the s2 r33 start being produced? Thanks

[Lithium]

Feel the compressor wheel on the S2 R33 turbo, its nylon - and it feels plasticy, and the obvious not looking steel thing

I am pretty sure the R33 S2 turbo is the same spec as the R34 one.

[Cubes]

I would think the R34GTT turbo would have a slightly bigger compressor or what not.

It makes 206kw from factory compared to 187kw from the R33.

I highly doubt they kept the turbo specs the same.

[dojobi]

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]

That is true, however I am looking at Nissans history with turbo's.

S13, S14, S15.

R32, R33 S1 & S2... All have slightly different turbo's.

Sooooo My thinking is why would they have stopped it with the R34??

[dojobi]

Yeah good point. I have heard of quite a few R34 turbos failing at lowish boost (around 0.7 Bar), so that probably does indicate it is a different turbo.

[Cubes]

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]

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]

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.

[dojobi]

I didn't even think of different valve sizes. What you're saying makes sense though.

[B0oStEr]

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.

[R34GTX]

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.

[RiverSide]

Smoke..............

screehing sounds due to the wheels scoring the housing........niether of those are nice to see or hear.

[JAPCAB]

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??

[Bass Junky]

R34 GTTs have a higher static compression than the other motors.

Doesn't this create more heat and therefore more chance to blo the exhaust wheel?

[Abo Bob]

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'.