Gt3076r Specifications - Clarification Needed

[evsr31]

Hi Guys,

Seen a few threads on here but really just wanted some clarification from the experts and I know that the GT3076R is quite a popular upgrade for an rb25.

Looking at putting one on myself, but there's 2 different options.

Apparently Garrett released a GT3076R part no (774067-5001) and it has a T04S 4" bellmouth comp housing, specs below -

Turbo Family: GT30

Turbine Inducer: 60.0mm

Compressor Inducer: 55.0mm

Compressor Exducer: 76.0mm

Compressor A/R: 0.70

Turbine A/R: 0.82

Bearing Type: Ball Bearing

Bearing Cooling: Oil & Water

Pic listed on their site for this particular turbo -

And then there is the other Garrett option - GT3076R (aka HKS3037S) part no (700177-7)

Turbo Family: GT30

Turbine Inducer: 60.00mm

Compressor Inducer: 57.00mm

Compressor Exducer: 76.2mm

Compressor A/R: 0.60

Turbine A/R: 0.82

Bearing Type: Ball Bearing

Bearing Cooling: Oil & Water

Very slight variances apart from the 0.70 A/R compared to 0.60...

I can get the first one for around 1650, and the one with the anti surge (700177-7) comp housing for about $300.00 more..

Going a .82 ext gate option, has anyone tried the first one? and results?

Edited August 3, 2009 by evsr31

[R31Nismoid]

yuk @ the first one - T04S/7 blade wheel.

[evsr31]

That pretty much says enough, are they hopeless for decent figures and response? It's what I've heard that the 7 blade ones are shit.

[discopotato03]

The part number for the port shrouded turbocharger one is 700382-12 , 700177-7 is its cartridge number - basically the center section with both end housings removed .

This is my opinion based on my research and hundreds of peoples findings all over .

The surge ported one has the more modern compressor wheel and is the same era technology as its turbine wheel . What people call the S wheel is a "T" series wheel designed to work with T era turbines .

That aside the cheaper one with the "S" compressor has a larger bulkier heavier compressor housing so it's a bit more difficult to package . If nothing else weight and bulk are best avoided where possible .

There are a lot of reasons why the surge ported GT3076R is the superior unit and there is a weeks worth of reading on this site just on these units .

It the cost was the only criteria you buy the cheaper one - and regret it ever after . $300 is a tidy sum of money but it's chicken feed compared to buying an inferior turbocharger and having to right the wrong . Those wise to the topic won't want to buy the inferior turbo no matter how new it is and the only cost recovery strategy is selling to a newbie or cost cutting to get rid of it . So lets just say you resell a now "used" turbo for several hundreds less than you paid for it and have to wear the cost of the new more exy better turbo .

So with the real GT3076R you get a better compressor wheel in a lighter more compact compressor housing AND you can use any of the available Garrett or HKS GT30 turbine housing sizes ranging from 0.61 A/R to 1.12 A/R and it shouldn't surge .

Search GT3076R and GT3037 and take note of people who have real world experience because they've been there done that .

I'm cooking up , if I can source the bits , a slight variation of the GT3076R which is all Garrett parts and no sneaky back yard BS . If you can wait a little while we'll see if it gives the desired results . If not buy the real GT3076R and know you have one of the better "GT30" family BB turbo options .

Over to you , cheers A .

Edited August 3, 2009 by discopotato03

[evsr31]

Cheers mate, I was hoping that you would post in this thread. That has cleared up everything.

I will be going a .82 ext garrett housing, supporting mods (z32 afm, 600cc squirts, 38mm gate) and eventually cams to help with the lag issue that would probably be expected with the bigger .82 housing.

[JonnoHR31]

just to give you an idea my 3076 hits full boost (19psi) around 3600-3800 depending on load. may sound laggy but it really isnt once you drive it. down low i actually prefer it to the stock turbo. mynes on stock manifold with internal gate btw, so with a good manifold and external gate you should decent boost even earlier

[Aberax]

I just bought myself this a few weeks ago.

Some people i have been speaking to in the SA section say that this turbo is too big for a RB25, and that it is going to be real laggy. But i wont really know for a few weeks till i have it installed. That is the 0.82 rear housing i think, it has it stamped inside somewhere.

[evsr31]

will go off

[evsr31]

Just to show all those interested in investing in one of these, this is what I went with. the GT3076R .60 a/r, .82 external gate rear housing.

[RS500]

very very good choice.

[evsr31]

Should go off, don't want to run too much over 17-18psi through the stock 25, thinking it will make around 270-280rwkw on about that.

Cheers bud

[huddy]

nice choice! I've got exactly the same thing for my 26/30 woot

[old mate]

hey mate have you put this on yet? when does it hit full boost? also how does it fell to drive with?

[SimonR32]

nice turbo, i would have personally gone a v-band rear but that isn't a huge deal

they are mint turbos, one of my favorite

[Aberax]

I got mine on a few weeks ago, see's full boost around 4k rpm. It is running 15psi and the car is making 265rwkw, boost hits pretty hard....love it. As it is spooling sounds like a jet.

[old mate]

what size rear is that with mate?

[Haines]

full boost at 4k sounds abit laggy

is it an internal gate

when i had the internal .73ar it was laggy but still full boost before then

with my external mine hits 18psi around 3200 - 3500 (.82ar) and thats with a .5 bar spring with the gain turned up on the EBC to crack at 14psi

so its way more responsive then the internal gate

I think it will get better still when I put in the 1 bar spring

[NYTSKY]

GT3076.82 pumping out 360rwkw, 23psi by 3900rpm need i say more

[juggernaut1]

GT3076.82 pumping out 360rwkw, 23psi by 3900rpm need i say more

[aDrew_C]

You should probably mention the E85