3071 Garrett

[BHDave]

yeah, definately not the proper garrett housing

[Simon-S14]

[burnsie]

hey guys ive got a gt3071r but with the .62 rear on my rb20det. i made 241.4rwkw but did see over 250rwkw but backed it off due to stock internals i make full boost at 4100 and pulls all the way to the limter which is 7600. im very happy with it

[Cubes]

Wouldn't know which GT3071 it was Burnsie?

[Simon-S14]

or what rear housing it was?

[discopotato03]

Hi Simon , I don't suppose that turbine housing has 0.78 A/R on it by any chance ?

It looked to me like a housing that I believe GCG Had made to get around the shortage of RB25 and BB VG30 turbine housings .

As for the Garrett cartridge there could be some issues there . The Garrett ID tag mentions GT2835R and its the one HKS uses in their GT2835R turbo .

Garrett and HKS put a different spin on the "R" designation . In Garrettspeak they tack the R on the turbo models name ie GT3071"R" to show it has a rolling element or ball bearing cartridge . HKS use an R on the end of some turbos they market ie GT2540R and GT2835R , from what I can tell it means the highest potential power producing version of a turbo series - biggest trim wheels and possibly housing A/R's . Mayby R for race edition ?

I wouldn't write the cropped GT30 turbine off as crap , it works reasonably well as long as the compressor option is sane and the housing families and A/R's are suitable . One thing significant with that cartridge - 700177-5004 is that its cropped or ~ 56.5mm GT30 turbine happens to be in 90 trim . Usually turbo manufacturers make turbines in large trims when they want low restriction and not necessarily a large A/R turbine housing . Because the exducer diametre at ~ 53.6 is large in relation to the major diametre restriction to flow through the blades will be low - as will its ability to "spool up" at low engine revs and load . Its a trade off biased towards high end performance (high flow with low restriction or turbine inlet pressure) . On a track car with close spaced gear ratios and a 4-8 power range it would be the way to go . Another way of looking at is if for instance Cubes RB30 was limited to using a GT2835 turbo the largest available turbine trim (90) and A/R turbine housing (1.12) would be virtually essential to not have it choke on its own exhaust gas . In that instance the turbo is a little small for the engine so supersizing it would be the only way to make it acceptable .

Where the wheels fall off is when you have an RB20 or 25 that generates less exhaust gas flow , large trim turbines don't always react positively to smaller A/R turbine housings used to pull down the turbos boost threshold . Obviously it has to help but if you have to go very small to get some boost at round town speeds it all falls apart at high revs and loads .

Sorry to sound negative but there are other issues - namely available T3 flanged turbine housings in the GT30 family . HKS's GT Pro S housings may not work given that they are already very thin on the wall seperating the turbines outlet and the wastegates vent path , it would be expensive to reprofile a HKS housing and have it crack . Garrett don't make T3 flanged GT30 housings for either the 84 or 90T cropped GT30 turbine - never have . So for a purpose designed housing for the cropped 90 trim your stuck with HKS housings and I've only ever seen them in T28 flanged GT30 housing form .

All that really leaves you with is an aftermarket housing which I think your one has or a bored out Nissan/Hitachi housing . Your call there .

If it was me using a GT2835 type turbo I'd prefer to stick with the 84 trim cropped turbine because there are good housings like the HKS GT Pro available for it and it would be aimed more at being broad range than mid to top end performance .

Before I finish there may be a bit of confusion between cartridge and turbo assembly part numbers . 700382-xxxx are BB GT30 complete unit part numbers . 700177-xxxx are BB GT30 series cartridge numbers .

To use the above example 700177-5004 (cropped 90T GT30 turbine with 71.1mm 56T GT35 compressor) , this is the cartridge number . My list of HKS bits shows that -5004 cartridge was used in three versions of the GT2835 , being

700382-5004 -5020 and -5021 . The differences would have been housing type and size because those three all use the same cartridge and wheels .

Again your call but I think you need to talk to people who've used that 90 turbine trim before fitting it and not being able to exchange it . I wouldn't think Brett would have a problem exchanging it if you you asked him but you need to have an idea what you want from a turbo and what different versions are likely to do . If you can find someone with a HKS GT2835 Pro S on an R33 that would give you a bit of an idea what to expect from one . You don't have to necessarily buy the HKS turbo because with the Pro S turbine housing you can make one up with the cropped turbine 84 trim cartridge and comp cover .

If you are sure you really want what I call the real or 60mm turbine version GT3071R then only the 700177-5023 will do . I cannot tell you exactly what power chartacteristics it will give on a reasonably std RB25 because I've not tried that combination . I bashed out a bit yesterday afternoon in Mafia's 300 Kw thread so possiobly worth a read .

Out of fingers cheers A .

[Cubes]

Sorry disco.. I didn't mean crap as in the turbo is crap but rather it wasn't what was asked for.

As for the .7 rear; the slight indentation between the wastegate and the turbine wheel looks identical to a .7 turbine housing I saw down at ATS in Adelaide. So quite possibly it is.

It might be a good thing for the power you are after Simon. You were after 250-260rwkwish I remember. It should drop you smack right there with slightly better spool and mid range compared to the slightly larger turbo. All though it doesn't leave much headroom does that really matter for its use?

[burnsie]

ill ask my mechanic later on this arvo and ill get back to guys

[Simon-S14]

discopotato: wow thanks so much for that informative read!! Given me something to think about thats for sure. I think i will try this turbo anyway and see how it goes, at least i wont need a custom dump pipe now!

Cheers

[Simon-S14]

Just spoke to GCG and discopotato is indeed correct, its the custom .71 AR housing.

[skylinecouple]

Just curious, how much did they charge you ? I'm reading all this and not going to get anything till I know which is the right way to go. Lithium looks the goods so far, GT 3076 .82 rear. Is yours the one GCG want $2,600 for ?

[BHDave]

what!!! You could spend 1k on shipping and still have a 3076 with a garrett IW housing for less than that from ATP! atp 3076

[skylinecouple]

I was thinking ATP but wasn't sure. Thanks Dave. Don't suppose you know what fittings and actuator I should ask for do you ? I figure I should just ask them on the phone.

[BHDave]

No idea on fittings or actuator to be honest. I'd have thought there would be a bracket of some kind to mount a fairly standard aftermarket actuator.

Personally i'd get the turbo on the manifold and do a measure for lines, then take the turbo, old lines/banjos and your measurements up to motorsport connections at seven hills and get the right adapters and lines.

They will knock up the lines on the spot and you will know that they'll fit properly

[Devils_Advocate21]

you dont want a 3037pro s dyno sheet do you with the 87 housing?

[skylinecouple]

I think the .87 if you could get it would be over the top. On the ATP website there is a 3071 with anti surge intake. Now that looks interesting. What effect would it have. Also, should I get the recessed waste gate as per normal or the flapper module that bolts to the turbine housing. Can someone look for me ? My wife is an executive with DHL and can arrange delivery from Hayward, CA, USA. If I can get these for a good price I may buy a couple at a time. Spoke to Yavuz at Unigroup and he seems to think the 3071 with .63 will make 250-260rwkw. I just can't see it with Lithium and Cubes needing a .82 for their 270rwkw. So do I go the anti-surge 3071 with .82 or .63 ?

[Cubes]

I don't believe you need the antisurge comp cover on the 71mm comp wheel. The portshroud 'apparently' slightly reduces the comps efficiency; a trade off for preventing surge.

250-260rwkw from the GT3071 with the .6 I see as possible.

The difference is lean on it much harder and it won't make power as easy as the .8 rear will or for a given power it will require more boost, it will at some point hit a brick wall and require better fuel due where as the .8 rear is able to get that exhaust gas out just that bit easier and will/should continue making power; providing the comp wheel is able to keep up with the airflow. So with the GT3071 as I said in a round about way above I think is a good match with the .6 rear. Going the .8 I'm not so sure would be worth while as your trading only 20rwkw for a slightly less responsive, doughier setup.

From what I can tell going by how mine appears to be running with the GT30 .8 the 71mm comp wheel should on my setup provide enough airflow for ~280-290rwkw.

The 76mm comp wheel 'should' provide enough airflow for ~330rwkw. So it could do nicely with the .8 rear to make use of all its compressor flow.

A .6 rear on pump fuel with the 76mm comp wheel I think is kills its potential a little.

I have seen 323rwkw from the 76mm comp wheel before; .8 rear, 254 cams and exhaust manifold on an rb25.

I have no idea what the results would be like with a .6 rear GT3076 and a pair of cams; possibly worse due to high exh manifold pressures?

I'm soon to attempt it with a set of slightly larger cams but with std inlet manifold and exhaust. Shall be interesting to see.

[donut_kng]

If anyone is interested I am looking to sell a 3071R kit, Exhaust A/R 0.71, Compressor cover A/R 0.5, with IW. Also have a custom intake pipe, elbow and a heap of silicon joiners, bits n pieces. Only done about 800kms on 14psi. PM me an offer

[Lithium]

If I can get these for a good price I may buy a couple at a time. Spoke to Yavuz at Unigroup and he seems to think the 3071 with .63 will make 250-260rwkw. I just can't see it with Lithium and Cubes needing a .82 for their 270rwkw.

Haha just because thats what we're both running is by far not because we "needed the .82 to make that". I don't have a boost controller, I am running completely off the actuator and was just loading up preload. If I went any higher it was going to start creeping - it made the 270rwkw REALLY easily. It would have made quite a bit more but we put more fuel in to make it run ~11.6:1 to keep the motor understressed relatively speaking.

If/when I get a boost controller and following how easily the car gained power when we did things, I expect it to crack 300rwkw without too much stress- just a bit more boost. People have made over 300rwkw with the .63 BUT it'd be a yuck way of doing it.

Edited November 8, 2007 by Lithium

[discopotato03]

I don't suppose anyone is intending to use the HKS cast manifold/ext gate and a real GT3071R ? I'd like to know more from the feller who had the real GT3071R 0.63 A/R on the RB20 as well .

A broken record I know but the cast manifold and ext gate + the TS GT32 turbine housing is going to be as affordable as it gets and give good all round results on a GT3071R/GT3076R .

When you team a pair of big trim wheels ie 84T/56T low end is not the combinations strong point , it seems obvious that Garrett have leaned towards big trim wheels so that small and medium frame turbos can give acceptable gas flow (both sides) on reasonably big engines . This keeps the turbo compact in relation to the engines physical size .

Another thing you find snipets of if you dig deep enough is that the real GT3071R is basically a productionised version of the competition oriented TR30R . These use a 60mm version of the NS111 turbine in 76 or 73 trim , NS111 series are 9 bladed rather than the GT30 UHP's 10 and almost certainly use a different inducer tip width and turbine housing nozzle form . The smaller 53.85mm version of this turbine in 76 trim is most of what makes the better versions of the GT28 BB series like Garretts GT2860RS and GT2530 work as well as they do .

The turbine trim size alone makes a huge difference to spooling a turbine , if the choices were small trim big A/R or big trim small A/R the former almost always gives a better average result . Edit : A/R meaning turbine housing size .

I know most are tired of hearing it because of cost reasons but twin scrolling is the only way to have med-large A/R housings that work up high and not suffer down low with large trim turbines . The Cheaper way to achieve it is with reasonably large wheels and more medium sized wheel trims ie 78/52T rather than 84/56T . Now Garrett for some idiotic reason don't seem to be in any hurry to offer their GT30 and 35 UHP turbines in say 78 trim or market the 71/76/82mm GT compressors in the 50-52 trim size range . If and when they do you'll start to see spool differences in the GT30/35R turbo ranges just like there has been in large frame GT BB turbos like some GT3782R's/the GT4088R and the T51R . I suppose you could include the T04Z even though it has a very large trim compressor (63T) , the saving grace is its dinosaur T04 turbine in 76 trim .

Until things change the workable options are all expensive - more cubic inches/twin scrolling/custom compressor options . I'm guessing turbo wise things will change but who knows when and how - that will depend on how much pressure the market puts on Garrett or if their oposition makes more effective turbos and starts to steal their market .

Cheers A .

Edited November 9, 2007 by discopotato03