Hks Gt2835 - Alternatives?

[Philip]

I'm currently running a Tomei RB28 with A'pexi V-Max 270/11.4 cams and top-mount twin externally-gated HKS GT2835s with 0.61 A/R exhaust housings.

One of the turbos has killed its bearing cartridge and I'm interested to know what the current options are as to bolt-on replacements, before I spend more on going for a single ...

I'd like to keep the reasonable response of my current small-A/R 2835s but with more power (looking for ~750 bhp at the flywheel) - any suggestions?

Thanks,

Phil

Edited May 2, 2006 by Philip

[R31Nismoid]

2835-R's i think are a step up from then normal 2835

i've been in a car RB26/2835R's (RWD 32-t) and ive never been giddy like i was the day i got out of it.

Alternatively, the t04z is the way of the future

[Philip]

2835-R's i think are a step up from then normal 2835

i've been in a car RB26/2835R's (RWD 32-t) and ive never been giddy like i was the day i got out of it.

Alternatively, the t04z is the way of the future

Thanks - I can probably source some more HKS GT2835s, but was wondering if there were any newer generic Garretts or similar available that came recommended.

If I was going single, T04Z, GT4077R etc. would be high on the list.

Phil

[paulr33]

Go Endless R32

[discopotato03]

Yes there are some options . Brett at GCG rebuilds the GT BB range so if its just the bearing cartridge should not be to difficult . If the wheels have rubbed on the housings it may be a different story .

Garrett do a turbo they call the GT3071R "WG" for wastegated and it I think uses a similar cartridge to the GT2835R depending on which turbine and compressor trims your 2835R's have . If you can give me the numbers off the turbos ID plate (should be something like 700177-00XX or -50XX) I'll check it out .

Brett sells some of the HKS range of unique turbine housings so he may have or be able to get the next size up of turbine housing which from memory would be .73AR in T28 flange .

The listings for GT2835R I have are .

CHRA No 700177-0002 , -0003 , -0004 and -0001 I suspect is another possibly 48 comp trim variant .

The unit numbers I have are 700382-2 , 3 , 4 , 6 , 7 , 18 , 19 , 20 , 21 and -24 .

If that -1 CHRA is a 2835 its unit no is 700177-0001 or -5001 .

Hope this helps cheers A .

[discopotato03]

Yes the "R" variant has the larger 90 trim turbine and 56 trim compressor . The std 2835 uses an 84 trim turbine and 52 trim compressor .

Just on the "R" prefix , I always tack it onto the end of Garrett GT BB turbos because it usually means rolling element centre section .

Cheers A .

[Philip]

Yes there are some options . Brett at GCG rebuilds the GT BB range so if its just the bearing cartridge should not be to difficult . If the wheels have rubbed on the housings it may be a different story .

Garrett do a turbo they call the GT3071R "WG" for wastegated and it I think uses a similar cartridge to the GT2835R depending on which turbine and compressor trims your 2835R's have . If you can give me the numbers off the turbos ID plate (should be something like 700177-00XX or -50XX) I'll check it out .

Brett sells some of the HKS range of unique turbine housings so he may have or be able to get the next size up of turbine housing which from memory would be .73AR in T28 flange .

The listings for GT2835R I have are .

CHRA No 700177-0002 , -0003 , -0004 and -0001 I suspect is another possibly 48 comp trim variant .

The unit numbers I have are 700382-2 , 3 , 4 , 6 , 7 , 18 , 19 , 20 , 21 and -24 .

If that -1 CHRA is a 2835 its unit no is 700177-0001 or -5001 .

Hope this helps cheers A .

Great information - thanks very much.

The cartridge number on mine (48 trim compressor) is 700177-0001. I'm going to go for the 52 trim compressor assuming I can get the larger 0.75 or 0.87 A/R exhaust housing somewhere in the UK.

Phil

[discopotato03]

Yes the turbine housings from HKS would be .73 and .87 AR ratio .

Always remember that going up in housing AR increases the gas flow ability at the expense of gas speed . I would be wary of going too big because you are basically doubling the difference with two turbos . Any increase in turbine housing AR and compressor trim will make them come on boost later that what you have now .

I would be doing the sums on the cost of a pair of HKS GT2835's vs either a HKS TO4Z or a Garrett GT4088R or Precisions hybrid GT4067R . Actually I'd Email Geoff Raicer from Full Race .com in the US as he's had lots to do with the GT4088R and GT4067R . Arguably you can probably make the power with good response and low turbine inlet pressure if you get the manifold and turbine housing AR spot on . Geoff has used twin external gates on split pulse manifolds for single turbo engines so maybe you can re use yours . In Americanlish twins may look "bling" but the modern single is hard to beat from a weight and complexity point of view and costs often a lot less .

OMG the twin turbo terrorists are in coming , bye - ducks ...

[Philip]

Yes the turbine housings from HKS would be .73 and .87 AR ratio .

Always remember that going up in housing AR increases the gas flow ability at the expense of gas speed . I would be wary of going too big because you are basically doubling the difference with two turbos . Any increase in turbine housing AR and compressor trim will make them come on boost later that what you have now .

I would be doing the sums on the cost of a pair of HKS GT2835's vs either a HKS TO4Z or a Garrett GT4088R or Precisions hybrid GT4067R . Actually I'd Email Geoff Raicer from Full Race .com in the US as he's had lots to do with the GT4088R and GT4067R . Arguably you can probably make the power with good response and low turbine inlet pressure if you get the manifold and turbine housing AR spot on . Geoff has used twin external gates on split pulse manifolds for single turbo engines so maybe you can re use yours . In Americanlish twins may look "bling" but the modern single is hard to beat from a weight and complexity point of view and costs often a lot less .

OMG the twin turbo terrorists are in coming , bye - ducks ...

I would go the GT40 single route without question if I was starting afresh, but there's the expense of turbo, manifold, downpipe, inlet, oil and water lines etc. to consider; whereas I just need some new cores and maybe exhaust housings to get going with what I have.

It seems that the 0.61 exhaust housings might have been too small in any case (RB26 kit usually comes with 0.87 A/R) - only just over 500 at the hubs at 1.6 bar on a Tomei 2.8 bottom end and A'pexi V-Max 270/11.4 cams ...

Phil

[nfi]

GTRS's low mounted can make ~800hp at 1.6bar. I've seen it on a built rb28.

Full boost by 5krpm.

Looks stock as well.

Otherwise I would go T04Z if you want a single or a T78 33d if you want a little more.

[Philip]

Yes, I know that GT-RS work very well, but I already have the high-mount manifolds and supporting hardware so I'm sticking with it for the time being.

Phil