Garrett Gt3271 On A Rb25

[Mr Jollwah]

Have done a search and couldn't find much info about anyone trying a GT3271 as a upgrade for a RB25, is it no good am i missing something?

Would it be suitable for someone who's car is 100% street driven.

Turbine A/R can be either 0.78 or 0.69 (wastegated)

Anyway here is the comp map.

[BHDave]

Bit of an oddball looking thing isn't it! I don't think it would fit on a stock manifold to be honest.

Potentially it could be very good with the right manifold (split pulse), but it is still plain bearing, and the turbine is probably a touch on the large size for the compressor.

You'd be better off with the ball bearing 3071 in a .63 IW housing IMHO ( the proper 56T 71mm comp and 60mm GT30 turbine), or one of the ATP twin scroll rear ends if you really want a split pulse housing.

[Mr Jollwah]

Was thinking it could be ok with the 0.69 AR Turbine.

[Dale FZ1]

It does look an oddball. I've looked at this unit before, thought it was probably best suited to a larger capacity/lower revving engine not chasing bucketloads of power but looking for linear delivery. Perhaps something like a Falcon or Commodore running mild boost.

Turbine efficiency and flow capacity data provided by Garrett does not look fantastic, but the T3 flange means it should bolt on to a stock RB25 manifold.

I tend to agree with BHDave. The GT3071 with 60mm 84T + .63 IW housing is probably a far better option, but if you want zippy immediate low-down response then any of the three trim options in a GT2871R based high flow would do the job quite nicely.

FWIW, you should definitely look at the split pulse option 3071 available from ATP or full-race.com and check the price/availability.

Edited May 12, 2007 by Dale FZ1

[Mr Jollwah]

Yeah i knew it looked weird just tryin to be a tightarse, only $1100. I suppose that is expensive if it is not suitable.

Twin scroll GT3071R looks great but i think it maybe to big. As I am after low to midrange power. Shame GT2871R doesn't come in T3 Flange.

Does ATP make a twin scroll turbine housing for the GT2871R as i feel that would be ideal.

[Dale FZ1]

Check ATP's website, but that's the only one I could see.

Check hp-inabox because it seems they might have access to OE replica housings as an alternative to getting your own unit high flowed. All of the 2871 cartridges are good in their own right, and you can choose a spec that meets your performance needs in the 220-240 rwkW range, with zippy performance.

The major difference between this option and the big brother 3071 would be in the very bottom end 1500-2500rpm and top end 6000-7000rpm ranges. Better breathing up high will yield stronger power at lower boost without it tapering nearly as noticeably, but I doubt you'd get that zippy/flexible response down low from the 3071.

There MAY be split pulse options from other manufacturers, if that is something you really want. Might be worth a search, and let us know?

Edited May 12, 2007 by Dale FZ1

[discopotato03]

Garretts GT3267 and GT3271's are not bad really for a plain bearing turbo and it looks like the more modern centre section than the old T3 and small shaft T4 turbos had .

They are availabe with a couple of different compressors and the 71mm I think using the 71mm GT35 series (BCI-18) family . If thats the case its basically a plain bearing version of the wheel that the GT2871R 52T and GT2835 52T use . Wheel backspacing and bore size are different for BB vs plain bearing cartridges . If you look at the compressors from some GT BB turbos you'll notice they have a hexagon behind the compressor lock or jamb nut . This is because when used in a ball bearing cartridge they were modified from the plain bearing form . In plain form they generally have a threaded bore and the hexagon is used to screw up and tighten the wheel on the turbine shafts thread . BB spec turbines usually have a smaller diametre where the wheel lives and fixed with a locknut so most but not all of the original hexagon gets machined away . With backspacing ball bearing spec wheels can sit closer to the shorter BB bearing housing because there is no need to allow space for the non existant plate/collar thrust bearing . The BB wheel just has a bit more off the back and a smaller plain hole through the guts , spot face the outer end for the nut to bear on and toss it on a BB cartridge .

I'm not certain but the turbine is probably an early diesel design . If you search GT32 turbos you will find that people in the US have played with them on some Subaru engines and a few others . There are dyno plots of the 67mm vs 71mm compressors although they speak of them in terms of pounds (pounds of airflow capacity) .

I wouldn't get too excited over the wastegated housings because I'm pretty sure they only vent one side of the divided housing so no good for a petrol app . As a cheap twin scroll external gate turbo they're probably not a bad thing on an RB25 though I'd prefer the Nissan/Garrett style T04B compressor cover (two bolt in / 3 bolt out) to make it a bit more compact .

The .78 A/R twin scroll non gated turbine housing looks a lot like the one turning up on real GT3071R's and real GT3076R's doesn't it ?

Cheers A .

[Mr Jollwah]

I agree discopotato the non-gated housing does look familiar.

might be a good thing on GT3071 or GT3076

Anyway looked on hpinabox website and decided that one of their GT2871R with nissan hotside is what i need.

The wastegated turbine on the GT3271 seems to be quite similar to KKR offerings me thinks that these turbos use a turbine housing based on a diesel design. Does anyone think that the GT3271 maybe better that the KKR 430. Just a thought.

Thanks Guys.

[The Mafia]

I agree discopotato the non-gated housing does look familiar.

might be a good thing on GT3071 or GT3076

Anyway looked on hpinabox website and decided that one of their GT2871R with nissan hotside is what i need.

The wastegated turbine on the GT3271 seems to be quite similar to KKR offerings me thinks that these turbos use a turbine housing based on a diesel design. Does anyone think that the GT3271 maybe better that the KKR 430. Just a thought.

Thanks Guys.

Dale FZ1 has this setup and got some excellent results with it, I suggest you speak with him regarding a few things. He's full of ideas, and is highly knowledgable and motivated in this area.

[series2r33]

Anyway looked on hpinabox website and decided that one of their GT2871R with nissan hotside is what i need.

What turbo is this and how much is it?? I've been tossing up between a GT3040, or GT3076 with the .63 exhaust housing. What horsepower rating is this turbo and is it ball bearing??

I am between those 2 because i was told i can achieve the same power with less boost and the same lag with the GT3040 as apose to the GT3076. Just interested about this one now? Pros and cons between the 3?

[discopotato03]

Actually the modern equal (ball park) of the GT3271 would be the real GT3071R cartridge no 700177-5023 . I believe the same family compressor but in 56 rather than 52 trim . The GT3071R (real one) uses the 60mm 84 trim GT30 UHP turbine where the GT32 is from memory an ~ 64mm diesel design maybe HP series .

Virtually everyone who's used the .78AR twin scroll turbine housing on the real GT3071R raves about the result , gotta be something in it .

Cheers A .

[series2r33]

Thanks mate i'll definatly look into it,

I seen this from horsepoweinabox and it directly refered to the rb25det's. I've posted it just recently but i chuck it in here just for the hell of it since im replying anyway

The GT3037/3076 is an exceptional turbo for its HP range. It features a .6 surge slotted comp cover and a complimenting turbine/comp wheel ratio, making it a great bolt on upgrade for the 2-3 litre range engine.

This unit has a lot of flexibility in offered houisings. It can be supplied with a T25 .86 internal housing, a T3 .63 or .82 external gate housing and a recent edition is the option of internal gate T3 in .63 or .82 (these units are more expensive and subject to availability at the time). Usual ultra reliability and superb response from the Garrett ball bearing design.

Great upgrade for RB20/25s and other 2.5-3 litre's looking for some serious power.

[Dale FZ1]

Great upgrade for RB20/25s and other 2.5-3 litre's looking for some serious power.[/b]

And the emphasis is on SERIOUS.

Do you want ~ 300rwhp, or ~400?

Response, or power? or a big dash of both. That 3071 would be a great unit, but leave you without the stock-feeling response at the very bottom of the rev range. The 2871 based units will also be great, feeling similar in delivery to stock, just lots stronger. A 3076 won't be to everyone's likes/needs/abilities.

As long as you know exactly what you want out of your car, you can get something that will meet your demands.