Can someone please tell me why the 3071 Garrett isn't made in the T3 .82 housing ? I have been watching with interest the adventures of Mafia, Cubes, Dale FZ, and Lithium so have come to the conclusion that Dales turbo is too small and at the end of it's compressor potential. Mafia I think may be on to a good thing as would Lithium and Cubes but Cubes doesn't really fit here as the 3ltr is very different in behavior to the 2.5 ltr. Lithium is closer to the money with his setup and I'm just not sure if the lag might be too much. BUT..... The 3071 in a t3 .82 would in my opinion be the ants pants. I spoke to Morrie at Horsepower in a Box and he has a brand new turbine casting which is rated at .70 that bolts straight onto my bell mouth dump so before I go ahead does anybody think that turbine ( the .70 ) would be better on the 3076 with anti-surge compressor or the 3071 ? Looking at 250-260 without beating the intake charge to death and risking intercooler heating up too much on track days. I can get three laps in before the heat in the cooler starts to cause the check light to come on in the top of 4th gear. No, I don't want to buy a HKS 2835 as the kit is too expensive. The VG 30 on my gcg hi-flow would get me the power and for price, you can't beat it, but time to bite the bullet and go bigger.
The real reason is my car is faster than most and with the suspension changes is a pleasure to drive. I won't be selling it for some time. Besides, it would be worthless. So any ideas ?

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If you are going to get a 3071 then bite the bullet and get the proper 3071 with a proper garrett IW housing and get your front pipe modded to suit. If you look here this is the cart you want. As you can see in the text the turbine housings are interchangable with a 3076 as it's the same turbine.

If the HPIAB turbo is different to whats shown on the garrett site then you likely have a cropped turbine version which is a bit of a nugget.

Take a trip to chipping norton and see garrett direct or even gcg at condell park, because there is a .82IW housing available for the real 3071.

Now, just which is the Real 3071 and yes, I will be going to Garrett as they are down the road almost. For the easiest install would the 2.75 be better or the 4" ? Realistically, what potential has this combo got ? Got all supporting mods so with .82 housing this should be ok for a "comfortable" 250-260 wouldn't it ?

the easiest way to spot it is turbine size. 60mm is uncropped gt30. 56.5mm is cropped. 2.75 inlet is the easier to install as it is a closer match to the stock inlet size, 4inch requires a bit of mucking around.

It will easily do 250-260, it will stretch to do 275-280 i'd say.

Definitely sounds the go. Surely going the bigger compressor will cure hot compressor air and the .82 housing should allow more timing for better response.

im getting a GT3071R with a T3 IW housing and 60mm wheel so it will be interesting to see how it goes on a 25.. should have it on in a few weeks so i'll post up my results soon

I believe that at the level I am currently at, my turbo has nothing over a .82a/r GT3071R - but a GT3071R would have a fair bit over mine in terms of streetability. If you are confident you aren't going to get bored with 250-260kw, then I think you are on the money. My car is perfectly streetable, and even at the "underutilised" level it is at the moment I think it would be really really good on a track. It has an exceptionally predictable power delivery, once the thing is past its boost threshold the thing leaps into life as soon as you get on the throttle. A GT3071R could only be better It is nice knowing I potentially have another 100hp @ wheels of flow without changing it if I want it without adding any lag or changing it though....

Ok. 60mm, uncropped, 2.75" inlet. This should be interesting. Simon-R32 I hope you go ahead. I 'm hoping the less inertia required to move the 71 vs 76 should improve coming on to boost. One thing I'm becoming increasingly aware of is how important it is to go no lower than .70, .73 in the turbine housing or the RB 25 will choke. now, is there any chance of someone finding a decent price or is HPIAB the best around.

Hey guys I posted in the other thread, I'm running a GT3071R with IW and 0.8 housing. The turbo is the XTR bolt-on kit (required spacer already supplied)

The rest of the relevant mods are as follows:

Stock internals
Hybrid FMIC
Davies Craig electric water pump
Davies Craig twin thermo fans
Denso iridium spark plugs
Splitfire coilpacks
HKS exhaust cam gear(currently set to 0 tho)
Oil cooler kit
HKS turbo back exhaust and JJR split dump pipe
555cc nismo injectors
600hp tomei fuel pump
nismo adjustable FPR
Greddy profec b spec II boost controller
Haltech e11v2 ECU

Plus everything you normally change for modding the turbo, braided lines, custom piping, catch can, cold air induction etc

The car was tuned at MRC Performance in Castle Hill NSW.

I thought I'd be making around 240-250 rwkw with that setup on around 16psi.
To my suprise my tuner got 271 rwkw on 14psi and says if I get a better inlet manifold and exhaust manifold it should see just under 300 rwkw on 14psi! Might be pushing the stock internals a bit tho.

But anyways, there you go the GT3071R isn't half bad, the car comes on boost early at 3200rpm and pulls hard through to 6800rpm. I can post the dyno sheet if you would like, just thought you might be interested as not many people are running this turbo to my knowledge.

Cheers Steve.

Would you do us a favour and post up the dyno sheets please. This will help with a few mathematical reviews of the results recorded. I note that the engine is internally stock, so that any airflow development work is limited to fairly typical bolt-ons.

Also, either have a look at the ID tag on your centre section, to give us the necessary info to determine which spec GT3071 you have and gain the understanding of how it performed. There are three permutations:
700177-5003, or
700177-5004, or
700177-5023

All have the same 56T 71mm compressor, though housings may differ. Using some fairly reliable data, I’ve got calculations and a map plot that says it should require about 47 lb/min of mass flow at the boost level claimed to deliver ~ 430 crank hp which should deliver ~ 270 rwkW. That mass flow is at the edge of the map, and boost increase most likely won’t equate to efficient mass flow (and engine power) increase.

Turbine performance, as I am still learning, is one of the major moderating variables of whether the compressor can work to maximum potential, or consume a fair bit of energy scavenging cylinders which are being backed up by increasing turbine inlet pressure.

Before my understanding of turbine characteristics was much developed, I had reckoned about 245 - 250 rwkW to be as good as the 3071 with hybrid OEM housing + 56.5mm rotor would reliably do on an RB25. I can see that a GT30 housing + 60mm rotor would lift that significantly due to efficiency gains.

Long explanation cut short: Zilch please supply the dyno sheet, turbo CHRA # from the ID tag and housing A/R so I can see how close to the money I am. If your dyno sheets aren’t overly “happy” as Mafia asked about, then you should smile. But don’t expect to find any magical top end gains by just running higher boost. Mid range would be another story…

I think another 30rwkw just from intake/exhaust manifolds is a little bit ambitious of the tuner there Steve.
But it will be interesting to see either way as stated, would also love a dyno sheet with RPM

Hi nismoid, yes I couldn't agree more, I think it's much more likely it'll end up around 285 -290 but hey I can hope

I will post up the sheets for you guys as soon as I dig up my camera(just moved) Should be up by tomorrow for you

Cheers Steve.

i'll post up my result when i get the turbo on. Im not aiming for huge numbers, just want a nice and responcsive 250/260 rwkw

Actually there are five versions of the Garrett GT3071R/GT2835 group .
Just bashed this out the other day at the Silvia site but not everyone goes there .

This group of turbos is based on the GT30 turbine and Garretts 71.1mm GT35 compressor family . HKS sold all of the cropped versions and Garrett two of the cropped and the only uncropped version .

1) Cropped 84T turbine with 71mm 48T compressor 700177-1
2) Cropped 84T turbine with 71mm 52T compressor 700177-2
3) Cropped 84T turbine with 71mm 56T compressor 700177-3
4) Cropped 90T turbine with 71mm 56T compressor 700177-4
5) Uncropped 84T turbine with 71mm 56T comp 700177-23

My opinion only but the only time I'd go anywhere near a cropped turbine GT30 based turbo is if I particularly wanted a GT2835 Pro S . The cropped turbine is not a bad thing but there is a very limited range of turbine housings that work properly with it . The T28 flanged GT28 IW housings are a bodge with this turbine so avoid at ALL cost . The flange size is wrong for a single turbo Skyline anyway so no reason to go there .

Garrett most certainly do make T3 flanged integral wastegate GT30 turbine housings and the "real GT3071R" uses the matching uncropped GT30 turbine so they bolt together as a set .
I wouldn't write off the 0.63 A/R turbine housing as too small particularly on this GT3071R cartridge . To get high power (260-300) from the 71mm compressor your going to have to spin it a bit faster than the 76.2mm compressor in the GT3076R so the .63 is probably not as restrictive as you think . The shaft power required to drive the 71mm comp won't be quite as much as the 76.2mm one needs so it should spin up a little sooner and have slightly better transient response . I would think it would "windmill" a little faster than a GT3076R so you should get a bit more part throttle torque at lowish engine speeds . Cubes can give you the details of this theory .
I always thought that if I was going to bolt an IW Garrett GT BB turbo to my R33 it would probably be the real GT3071R with the REAL GT30 IW turbine housing in 0.63 A/R . I did try for a while to locate A HKS GT3037 Pro S turbine housing in 0.68 because that I think its as good as it gets for a responsive GT3071R or GT3076R single scroll turbo thats not a hybrid one off cartridge combination . As for the .63 , if Mafia can get 300 Kw from a 0.63 GT3076R which has a 500+ Hp caple compressor you should be able to get close with a 440 Hp capable one .

Remember the real GT3071R should have 700177-23 or - 5023 on its ID tag . To be doubly sure the turbine diametres are ~ 60mm x 55mm , if the turbine outlet or exducer diametre measures either 51.9mm or 53.6mm its not the real one .

Cheers A .

Thanks for filling the blanks.

I ran with the Garrett branded specs but worth throwing the full range of options that come from the HKS brand too.

Frankly, going with anything other than the 0.63 A/R turbine + 60mm rotor is probably missing the best of the GT35 71mm compressor which does need extra shaft rpm to perform. If it is being spun comparatively lazily by the 0.82 turbine, then it's missing the speed to move the air mass efficiently with part throttle situations. You'd end up with an artificially high boost threshold, with no appreciable high rpm efficiency gain.

Advice I received from a Garrett engineer is that the 0.63 GT30 is effective/efficient in service applications with 400 crank hp of mass flow, so working on plus/minus 10% I'd think it to be a decent match on the -5023 GT3071.

Again though, 270 odd rwkW would be hard to improve upon without internal engine developments.