The Garrett Gt30r Thread - Lots Of Info And Q's

[MR331307]

A customer of mines car has the .82 rear housing

just forgies and a head gasket and is making full boost at 3900rpm (18 psi)

his making 390 rwhp all day everyday driving

yet ive got a customer with a gt 35/40

same setup

.82 rear housing making full boost at 4000rpm (18 psi)

and making 422 rwhp of everyday driving

GT 35/40 WAY TO GO

(sorry Gt30 Thread)

Edited November 13, 2006 by MR331307

[Sammie]

can anyone give me some tips on what i posted on the first page i plan on ordering a few parts + a gt30 within the next week or so

[Roy]

A customer of mines car has the .82 rear housing

just forgies and a head gasket and is making full boost at 3900rpm (18 psi)

his making 390 rwhp all day everyday driving

yet ive got a customer with a gt 35/40

same setup

.82 rear housing making full boost at 4000rpm (18 psi)

and making 422 rwhp of everyday driving

GT 35/40 WAY TO GO

(sorry Gt30 Thread)

Interesting...some dyno sheets would be worth their weight in gold. I need to buy a T3 flanged turbo in Jan, sooner if can sell my current setup

[al_r33]

I know you're only running 8psi but does it seem laggy? Can you give me an estimate on the rpm vs boost levels? When is the full 8psi in?

It seems so be pritty early! not exactly sure but it is way befour 4000rpm & its not really laggy at all & on 8psi it pulls bloody hard for that boost! without being tuned!

But the fpr is getting fitted on thursday & should be getting tuned on friday! So i will post a dyno sheet when its done!

Alan

Edited November 13, 2006 by al_r33

[discopotato03]

The real GT3067R's CHRA or cartridge number is 700177-0007 or -5007 . The cartridge number does not change with the integral wastegate version . Garrett could possibly change the turbocharger assemby or unit number if they sell this turbo in IW form . They normally sell this turbo without a turbine housing and the buyer gets to choose which one they want .

Also no I have not seen a GT3076R surge on an RB25 though the port shrouded compressor cover tends to widen the map islands in the upper LHS - sort of takes out that semi circular dip so to speak .

I've been spending some time sniffing out GT3037 specs and HKS seem to rate the three comp trims ie 48/52/56 as being good for 420/440/470 PS though it would also depend on the turbine housing AR ratio . Garrett I think is rating their 56 trim comp version (GT3076R) at ~ 500-530 Hp .

People are getting into the 270-300Kw region with the GT3076R even though its 56T compressor/housing pair is good for ~ 50-55lbs flow in the 15-22 pounds boost area . So the compressor is easily capable conservatively speaking 500-550 Hp worth of air . To do 400Hp (300Kw) means 40lbs of air is needed and with 10% leeway 44Lbs . The 52 trim compressor fits in about here and would allow you to make the power but with a tad more shaft/wheel speed which is not a bad thing because turbine inlet pressure drops .

The downside is that 48 and 52T compressor versions are only sold by HKS (ouch) but compressor wheels are available (from Garrett GT bush bearing turbos GT3576/GT3776) being 76.2mm 52T , 55mm inducer , 5.45mm tip height and 7.40 mm threaded bore style centre . It would not be the end of the word to do the machine work to make it fit a GT30 based cartridge designed for a GT30/TO4S (76mm) or GT3076R (76.2mm) compressor . That compressor wheels part number is 434441-0003 .

Just because - details of the 82mm GT40 compressors from bush bearing GT turbos that use them .

48T 82mm 56.75 inducer 5.50 tip height 7.4 threaded bore Wheel Part No 448856-0019 .

50T 82mm 58.00 inducer 5.75 tip height 7.4 threaded bore Wheel Part No 448856-0016 .

52T 82mm 59.15 inducer 6.00 tip height 7.4 threaded bore Wheel Part No 448856-0009 .

54T 82mm 60.25 inducer 6.00 tip height 7.4 threaded bore Wheel Part No 448856-0013 .

Am trying to get a damaged/dead GT3582R cartridge to gut and measure up for alternative compressor wheel trims . The housing would be one from a TO4S and reprofiled for the GT40 wheel .

I hate unnecessary lag almost as much as I hate exhaust manifold pressure thats higher than boost air pressure . If I wanted a GT30 based turbo for an RB25 this is what I'd use , a bit more effort and money than an off the shelf GT3076R but better transients and no doubt fuel consumption more than make up for it .

Late Edit - I've seen mention of HKS selling a 48T GT3037 for the Subaru WRX EJ20 and this is possibly because the flat boxer four with long manifold runners and arguably weird pulsing from opposing heads makes them a little laggy at lowish revs .

Out of fingers cheers A .

[Lithium]

.82 rear housing making full boost at 4000rpm (18 psi)

and making 422 rwhp of everyday driving

GT 35/40 WAY TO GO

(sorry Gt30 Thread)

Interesting, I've seen people on here talking about that kind of spool with .63a/r GT3582Rs - and ~4400-4500rpm with .82, high 4000rpm with 1.06.

I'd imagine that all things being equal, a GT3076R should have a few hundred rpm on a GT3582R.

[discopotato03]

Lots of things affect where a turbo comes on boost . Examples are good vs average exhaust manifolds , tuning namely ignition timing , dump pipes , exhausts , static compression ratio , cam timing and lift , head work yada yada . Its too simplistic to expect just the turbocharger specification to have all the say .

All else being equal (except optimal timing and AFR's) you can expect a GT3076R to be more responsive than a GT3582R because its gas passages are smaller and its wheels have less pumping capacity on one side and more trapping capacity on the other . Also you cant really look at a GT3082R as a scaled up GT3076R because the ratio of turbine to compressor is slightly better on the larger turbo compared to the smaller one . I believe this is why the smaller trim compressor wheels work so well on the GT3076R/GT3037 . No one I know has tried the smaller wheel trims on a GT3582R so still a final fronteer . I reckon a custom backplate/adapter ring to mount the plain bearing GT4082's 82mm 50T compressor wheel and .58AR port shrouded comp cover would help make the torque mountain but probably better suited to an RB30 . The increased difuser diametre over the TO4S cover/backplate I think makes for wider islands at low pressure ratios so more inlet flow for less boost provided the engine can take advantage of it . Using an unmolested Garrett comp cover means factory clearence on the compressor blades and a ported shroud that is proven to work - many machined in by turbo vendors do jack shite .

Cheers A .

[Lithium]

I believe this is why the smaller trim compressor wheels work so well on the GT3076R/GT3037 . No one I know has tried the smaller wheel trims on a GT3582R so still a final fronteer . I reckon a custom backplate/adapter ring to mount the plain bearing GT4082's 82mm 50T compressor wheel and .58AR port shrouded comp cover would help make the torque mountain but probably better suited to an RB30 . The increased difuser diametre over the TO4S cover/backplate I think makes for wider islands at low pressure ratios so more inlet flow for less boost provided the engine can take advantage of it . Using an unmolested Garrett comp cover means factory clearence on the compressor blades and a ported shroud that is proven to work - many machined in by turbo vendors do jack shite .

The first part of your post I fully agree with and understand, just wasn't going to say it all for the sake of being concise

I'd love the money and the facility to try some of the combinations you have described, they sound really good in concept. I have it in my head you can get a 52-trim T04S covered GT3076R from some places? If I remember rightly the only GT3076Rs we can get here in NZ are 52-trim.

Now you mention the pressure in the exhaust manifold vs. the inlet side - how do you determine whats actually going on there?? I had otherwise assumed that the pressure on the turbine side (before wastegate opened) was a good thing, and would help spin the rotating mass up faster - and once the wastegate opens there is additional release. Anything not required to maintain targetted pressure ratio, completely bypasses the turbine housing/wheel and just goes "somewhere else".

Cheers

[The Mafia]

ok well, I am a little confused, but have an idea on what I should be looking at.

The GT3076 with these specs - (700177-0023 or -5023)

The Compressor wheel specifications should be : 76mm 56 trim

The Compressor Cover : (can I keep my .7ar or will it be better at .6 or even .5??)

The Turbine Specs should be: (I have no idea)

The Exhaust housing will be a Garret IW .86 Housing

Ok.

This is my goal.

I want a fairly responsive 270rwkw-290rwkw, and that will be nice to drive on the street. I have all the supporting mods. Boost needs to be 18psi or less, and yeah Comes full on before 4000rpm like the shitty one I have now.

Am I on the right track? Can anyone fill in the gaps?

Edited November 14, 2006 by The Mafia

[Cubes]

I don't believe a GT3071r will make 290rwkw as on paper its only capable of ~450hp. Which is... ~260rwkw give or take a little.

[The Mafia]

I don't believe a GT3071r will make 290rwkw as on paper its only capable of ~450hp. Which is... ~260rwkw give or take a little.

ok, well forget I mentioned the 3071 in my post above..

The 3076 it is.. Just need to fill in the blanks!

[r33_racer]

man isnt this turning into a mission and a half.

While were on this subject does anyone know the rough power rating of a gt30r with .63 rear. What hp worth of airflow can it produce? Is it 500hp worth? or 450? Cause isnt the big 1.02/1.06 whichever it is capable of 600hp.

[Dale FZ1]

After punching the numbers in, I would suggest:

700177-5007 cartridge (BCI18 76mm 52T comp, UHP 60mm 84T turbine)

0.54A/R comp cover as used on the GT3776R (turbo # 452159-1)

0.82A/R GT30 internal gated turbine housing

At the power levels targeted, a set of cams and inspection/tidy up of the ports would be desirable. The turbo specs should deliver the goods but improved volumetric efficiency for the engine would make it happen a lot easier.

[discopotato03]

Firstly Lithium the TO4S compressors are not real flash things in fact I'd avoid at all cost even if it means importing a real GT3076R from Aus or the US . Those wheels are 76mm where the real GT37 series are ~ 76.2mm , I know this is spliting hairs but its an unfortunate legacy of Garretts vague numbering system .

You can import the right ones , just because the turbo people don't bring them in doesn't mean you cant .

Exhaust manifold pressure or turbine inlet pressure is an evil and should be delt with accordingly : Quote Corky Bell .

The idea is to recover as much velocity energy from the hot expanding exhaust gas as possible while posing the LEAST possible restriction to its flow . The aim is to have lowest exhaust manifold pressure because when both inlet and exhaust valves are open in the cam/valve overlap phase if exhaust manifold pressure is higher than inlet manifold pressure it backflows into the chambers diluting the clean incomming charge air and pre heats it as well . Bad , very bad . The idea of the valve overlap period is for the cool incoming air to blow through the chamber area and purge the residual spent gasses past the exhaust valves into the exhaust manifold . The correct term is scavanging .

The waste gates function is merely to bypass exhaust gas away from the turbine when the compressor is spinning fast enough to achieve the desired boost . As the engines speed (rpm) increases its air demands rise so the compressor must turn faster to maintain the regulated pressure head across the inlet manifold . The downside of this is that the waste gate is regulating compressor outlet pressure not turbine inlet pressure which can get out of hand if not watched . This is why having a good balance of turbine to compressor (and their housings) is so important . If you look at big Diesel turbos you'l note that many don't have a waste gate and are said to be "free floating" . The turbine and housing are sized so big that the turbo never overboosts because there is insufficient gas velocity to go beyond a set boost pressure . This is all about minimum turbine inlet pressure . Granted those engines work over a narrow range with low peak revs . Some later designs are using smaller turbine sides and waste gates in an effort to have lower rpm boost response like OEM petrol engines do but it is a compromise . Overall power is usually more important than peak power because usually so little time is spent up there .

Most efficient use of exhaust energy to efficiently generate just enough airflow is what tends to work best .

Mafia the 700177-5023/-0023 is a GT3071R meaning 71mm or GT35 series compressor . They usually have a .50 AR ratio TO4E comp cover , yours is .70AR TO4S so won't fit . .86 is a GT28 turbine housing so you would need a .63 or .82 GT30 series turbine housing for the real GT3071R . Basically nothing off you turbo except oil/water plumbing will fit it . Even the oil drain pipe would need to be slightly modified depending on how far the turbo moves in relation to where it is now .

R33 Racer from my maps the comp/housing combination gives ~ 53Lbs flow at 2.5+ pressure ratio (1.5 bar or 22 pounds positive pressure) on the bleeding edge . If you can run it to its limit (130 000 + revs and 60%efficiency) may be good for ~ 580 Hp worth of hot air and maybe near the wheels mechanical speed limit .

I'm not certain but I think the turbo people have mentioned as being the 600Hp GT30R may be the GT3040R . I'm also researching ATM a comp cover from a truck turbo (I think a GT3576 on an Isuzu) because it has a .65AR port shrouded comp cover though not sure about for which wheel trim 52 or 56 . It may just get a little more from a hard worked GT3076R compressor side .

Garrett rate the thing at 500Hp though they don't mention turbine housing AR .

To give some idea the turbine map shows maximum turbine flow with the .63 turbine housing of ~ 20.5 lbs flow at 2.5 PR or 1.5 bar (22psi) . The .82 housing ~ 23.5 lbs flow at 2.1 PR or 1.1 bar (16.2psi) . The 1.06 housing shows ~26.5 lbs flow at ~ 1.85 PR or 0.85 bar (12.5 psi) .

1) 0.63AR Max flow 20.5 lbs at 22.0 psi .

2) 0.82AR Max flow 23.5 lbs at 16.2 psi .

3) 0.06AR Max flow 26.5 lbs at 12.5 psi .

This shows very clearly how maximum exhaust flow in corrected pounds mass or weight goes up as pressure or resistance to flow in psi drops . Its interesting how the flow has risen approx 20% while the resistance to flow has fallen almost 50% .

Never done this before thanks guys , cheers Adrian .

Edited November 15, 2006 by discopotato03

[Dale FZ1]

Top effort Disco. Demonstrates the difference between A/R capabilities very nicely, and how/why smaller housings can result in both early power drop-off and possibly induce detonation due to back-pressure related scavenging problems.

I'd suggest the 1.06 housing would be great for a dedicated track car (lowest buildup of back pressure) running full noise and consistent high rpm, but probably big enough to have a soggy bottom end. The 0.82 would give a happy medium.

Something I've not been able to get squared away is how to derive what mass-flow exhaust we should be looking at for a given power output. Obviously the mass is reduced significantly.

cheers

[Lithium]

Firstly Lithium the TO4S compressors are not real flash things in fact I'd avoid at all cost even if it means importing a real GT3076R from Aus or the US . Those wheels are 76mm where the real GT37 series are ~ 76.2mm , I know this is spliting hairs but its an unfortunate legacy of Garretts vague numbering system .

You can import the right ones , just because the turbo people don't bring them in doesn't mean you cant .

Yeah thats what I'd figured - I had independantly done research and decided on the GT37 job, but with a .63a/r turbine hsg at least in the meantime. My initial setup with it is stock internals and only 1bar anyway - so hopefully the .63a/r won't be too much of a huge problem. Tell me if you feel otherwise. When I go stronger internals, I'll probably go .82a/r and ~18psi.

Cheers on the manifold pressure rant as well - ties some things together I had been pondering about

This is mine test fitted to an RB20 for fab reasons etc (its going on my ECR33):

And with wg, dump pipe:

Got oil and water lines made up and the turbo in car now, just sorting out intake piping and the dump -> exhaust fabrication and then it should be pretty much ready to run.

[discopotato03]

Dale I think you'll find that the 700177-5007 is the 56 compressor trim GT3076R/GT3037 cartridge , I believe the -5006 variant is the GT3037 52 trim cartridge . That comp housing may not be a bolt up either as the GT37 bush/plate bearing may have different back spacing on its compressor wheel . May need a one off machined adapter/backplate to get it all right . Also I would think the .54 AR comp cover ratio is less than ideal , HKS used a .60AR port shrouded cover on their GT3037 52T . As I mentioned looking at a .65 version soon , just have to con the masters into tilting the cab on the said truck so I can get at the *&^% !

Lithium that doesn't lok like a GT30 turbine housing , more like a Ford style Garrett T3 housing . Sorry to be negative but the ext gate would have been better on the manifold as the 90 deg turn into the housings outlet hole upsets the flow in the tapering section of the turbine housing .

Cheers A .

[Lithium]

Lithium that doesn't lok like a GT30 turbine housing , more like a Ford style Garrett T3 housing . Sorry to be negative but the ext gate would have been better on the manifold as the 90 deg turn into the housings outlet hole upsets the flow in the tapering section of the turbine housing .

It is the Ford style one - using stock manifold, and the split in the Ford-style housing "looks" at least to be nicer than the concept of cutting the stock manifold, or using one of those nasty 90degree bend spacers. At this stage I'm only aiming for basic upgrade power levels - and getting enough flow to the external is the highest priority as I'm running a standard internal motor and want to keep boost levels in check. A lot of things will be changed when I end up with for forged internals - ie, new manifold and turbine housing...

In real world terms - for the stage I am now, how obvious do you think the upset flow will be - or what effect it will have?

[Busky2k]

Firstly Lithium the TO4S compressors are not real flash things in fact I'd avoid at all cost even if it means importing a real GT3076R from Aus or the US . Those wheels are 76mm where the real GT37 series are ~ 76.2mm , I know this is spliting hairs but its an unfortunate legacy of Garretts vague numbering system

AFAIK Disco the T04S compressors were also 76.2mm? Take a glance at the HKS GT2540 or the Tomei B8446...

[Dale FZ1]

Going on this spec page:

http://www.turbomaster.info/eng/applicatio...ings_chraGT.php

the -0007 cartridge gives a 52T comp wheel. It could be wrong though.

Also the pics (if accurate) from Garrett here: http://www.turbobygarrett.com/turbobygarre...76_452159_1.htm suggest that the 0.54 A/R cover has a ported shroud. This feature has become something of a “must have” for marketing rather than engineering purposes, given that it is intended to reduce the propensity for surge.

Point taken that it may in fact be a difficult cover to fit, but the impeller/housing combo actually seems to have a map suitable for Mafia’s needs with wide efficiency islands that are fairly upright on the left side (minimising the chance of surge as PR increases). What I liked was that it had published flow data.

Definitely keen to see what comes up with the Isuzu-spec housings – anything I found was in Spanish or Italian and a bit vague in many aspects.

cheers