Garrett Gt30r Flavours

[AWD2Go]

May be worth considering something off the shelf these guys (6Boost) are supposed to be fairly good

http://www.horsepowerinabox.com/HPIAB2/category15_1.htm

Just got an email from Morrie he said that he should have 4 x GT3076R in on Monday.

Edited January 19, 2007 by AWD2Go

[discopotato03]

hey AWD2go im going Garrett GT3076

Its going to be done my Bill Kane at Adelaide Turbo Services, hes assured me that the custom tubrocharger kit he makes up custom himself is one of a kind in Australia and is a very nice direct bolt up replacement for my stock manifold 2 dump. Hes quoted me well and has been a great help in changing my mind. Cant wait till next week when I go in.

Thanks everyone for helping me out youve been great get urself a yeah?

Paul.

Well unless he's getting his own housings cast and machined he'd have to be using std exhaust housings or the newer .70 A/R offering from GCG . No offense but I believe that only Garrett and HKS do propper housings for the GT30 turbine . All the others I've seen are based on the std Hitachi housing or a flange modified GT28 based housing . Plenty of "custom kits" out there but what yardstick is there to measure them by ?

Cheers A .

BTW , I hear that the Garrett Syd kit will not eventuate now . I think it was based on a GT3037S/GT3076R 52T and a custom dump pipe . It needed a spacer plate to clear the std exhaust manifold (comp cover) and unique oil/water plumbing as you'd expect . Plumb air in/out and thats about it .

Owner tells me the result was very good . I think he said the turbine housing was a Garrett IW .82 A/R .

Edited January 19, 2007 by discopotato03

[Dale FZ1]

Mines not butchered its just a normal 4 bolt 3" outlet with a nice taper up to the flange. The inlet is central and square. http://upload.silviansw.com/CT18U.JPG (my old GT2871R on the left)

http://upload.silviansw.com/CT10U.JPG

http://upload.silviansw.com/CT09U.JPG

1679-6 is the part number for the housing

AWD2Go, I assume you've changed manifolds with this particular upgrade? I noted the Garrett GT2871R housing - 5 bolt discharge, which would also mean a T25 flange.

That turbine discharge looks quite good - and points to why external gated units tend to have much less probs with back pressure with that expanding taper immediately after the rotor.

[-_-StRyDeR-_-]

300 I think is a bit too much of an ask for a GT-RS.

my mates 33 has just hit 290kw on 16psi with this turbo...

mind you...alot of mods and more then likly a power-happy dyno...

CJ

Edited January 19, 2007 by -_-StRyDeR-_-

[Dale FZ1]

I have my own ideas on compressor trims and exhaust housing A/R's . What I am aiming at is the 52 trim GT3037S/GT3076R because I don't need the 56 trim versions maximum airflow or lag penalty . BTW in ball bearing form these turbos should have .60 A/R TO4E compressor housings , you won't easily find the map of the 52 trim 76.2mm (GT37 comp series or BCI-18 family wheel) in this housing because it was a HKS spec turbo and they don't publish them . The .54 A/R compressor housing is a bush bearing OEM GT3776 truck turbo part . There is a .65 A/R compressor housing from a later bush bearing GT3576 but I'm still researching that one .

A very important point to remember is compressor covers with ported shrouds or air inlet boss . I think the slightly smaller trim comp (52T) will give me enough airflow for strong mid range torqe , the .68 A/R HKS Pro S exhaust housing (if I can get one) good response and a good integral gate vent path , the port shrouded compressor cover better response and control compressor surge .

Having driven an R33 GTST for a while now I'm not so sure 32 3400 rpm + boost threshold is a good thing . I'd really like that windmill effect the GT2860RS gave on my FJ20 and this is why having good turbine response in a turbo thats well balanced (comp to turbine flow) is important . My goal is strong torque in a reasonably free reving (and not exhaust choked) engine , I couldn't give a rats jats about kw numbers .

IMO a good strreet engine (RB25 in an R33) needs to be starting to pull from 2500 and if your lucky start to fall off in the 6-7000 rpm area . Provided you get some meaningful torque in the 3000 + range it should not fall flat on the upchanges . You'd expect to upgrade other things like porting cams IC ECU etc to achieve this with a production engine of this era .

Before I finish here using the smallest exhaust housing and the largest compressor trim version of any turbo is at complete opposites - most airflow for least exhaust flow . Not sure if this would be a desirable option with a GT3076R because the extra airflow won't be much advantage if the engine is restricted by the small turbine housing .

Disco I tend to agree on many points you've raised here, but my overall view is that if you want a mechanically stock RB25 to be lively down at 2500 then you're going to need a GT28 based turbine with its quicker acceleration. It seems as though once you get a GT30 60mm turbine driving things, its higher moment of inertia and the physical difference in housing size dictates that the effective torque range WILL be higher up the range. You may well move through the boost threshold at 2500, but it will start cranking real grunt somewhere around (above) 3000. The payoff is in unchoked flow through and past 7000. So the effective powerband is pushed further up the range. Very selective choice on spec though, can yield satisfactory (a nebulous term that one...) off boost performance.

Going for an earlier responding unit, I'd suggest that a 0.63 turbine is a must, combined with either that 52T / 0.54 A/R comp from the GT3776, or the 56T / 0.50 GT3071R. My calcs reckon each would be surge free, but the 71mm needs another 12000 odd rpm to deliver the airflow at the top end. Both would also offer the least amount of resistance to acceleration for the flow capacity. If I was to choose, and it could be done for a reasonable $$ then it would be to use the GT3776 0.54 comp assembly with the 0.63 IW turbine housing. Fairly well matched for flow on both sides, and the comp flow map is available. Beats a lot of guess work.

For the extra flow capacity, the 56T GT3076R would be a goer, at the cost of transient response and higher boost threshold against the other two. Then you'd have to choose power vs response and maybe go with the 0.82 turbine in order to take advantage of the comp flow.

In any case though, a 53.8mm turbine will just get up and boogie earlier but also sign off earlier. The "windmill" idea is attractive but I suspect you can't have it both ways using conventional (non variable) technologies. As an aside, I'm still very happy with my little highflow; very torquey and responsive right down low but flattens off about 5800 like a stocker. Quick and easy to drive on-road but maybe a bit light-on for the numbers for those who are interested in numbers.

Just my thoughts.

Edited January 19, 2007 by Dale FZ1

[Cubes]

Dale,

A bloke who runs on the same dyno as I has a GT28 on his RB25, comparing the dyno graph to a stock turbo'd rb25 the spool/power is almost identical down low and then the gt28 simply takes off and makes an effortless 240rwkw, I don't remember what boost it was running but it was fairly low, I remember thinking wow wind the boost in to it and that would really have some killer mid range (not that it already doesn't).

It really did look like an awesome street setup.

[Bl4cK32]

Its going to be done my Bill Kane at Adelaide Turbo Services, hes assured me that the custom tubrocharger kit he makes up custom himself is one of a kind in Australia and is a very nice direct bolt up replacement for my stock manifold 2 dump. Hes quoted me well and has been a great help in changing my mind. Cant wait till next week when I go in.

Paul.

ATS are known not to be the best setup from memory.

Just for curiosity sake, care to list us the support mods for your turbo?

[The Mafia]

I just grabbed a GT3076 (Branded a GT3037)

Goes pretty good. 6 Blade compressor, 56 trim, and a 84 trim turbine. The Compressor housing is a .6 port shrouded cover, and the turbine housing is a .82 garret IW housing.

Most of the action happens after 3500rpm, with the full 18psi - 20psi hitting at about 4000rpm.

If you want less lag, and a little less top end, get the .63 IW rear.

Whistles like a jet engine too.

[Cubes]

I just grabbed a GT3076 (Branded a GT3037)

Goes pretty good. 6 Blade compressor, 56 trim, and a 84 trim turbine. The Compressor housing is a .6 port shrouded cover, and the turbine housing is a .82 garret IW housing.

Most of the action happens after 3500rpm, with the full 18psi - 20psi hitting at about 4000rpm.

If you want less lag, and a little less top end, get the .63 IW rear.

Whistles like a jet engine too.

Nice.. How do you rate it to your old GT30? You did have the 7blade gt30 didn't you???

What power are you making now?

[The Mafia]

I've been meaning to update my thread about it, but to be honest with you, The old GT30 with a proper Garrett .63 housing would have done the trick.

I'm a little disappointed at the extra lag, but it still goes well. I'm about 400rpm laggier now. The top end is definately better, but I think it could have been more? Maybe I was just expecting too much? Lol, I should have got a GT35 with a .63 housing.

None the less, there was definately nothing wrong with that old 7 Blade GT30 I had. Made a lot more boost down low than the 6 blade wheel. Maybe because of the chopped up RB25 housing, wo knows.

I'm still contemplating taking the .82 housing off and whacking a .63 on, just not sure what sort of Top end I am going to miss out on.

[Dale FZ1]

I just grabbed a GT3076 (Branded a GT3037)

Goes pretty good. 6 Blade compressor, 56 trim, and a 84 trim turbine. The Compressor housing is a .6 port shrouded cover, and the turbine housing is a .82 garret IW housing.

Most of the action happens after 3500rpm, with the full 18psi - 20psi hitting at about 4000rpm.

If you want less lag, and a little less top end, get the .63 IW rear.

Whistles like a jet engine too.

This is one upgrade that's been worth the wait, to see how it all comes together. I don't know of any other SAU members who've gone down this exact path yet, so it is a ground breaker.

Hopefully it does give satisfactory (there's that term again) bottom end response with the sort of knock free top end pull that the TO4S based hi-flow seemed to have a problem delivering. Maybe a fresh thread Jono, with the background and some impressions on what this specific upgrade is like on the road?

[Pauly33GTS-t]

blac32... supporting mods now, are only full 3inch -> 4 inch turbo back exhaust with 600CFM magnaflow cat, air intake also. im doing the FMIC at around time after i put on turbo. theres no point in me getting a turbo i already had on there than the one i want. so ill be running stock boost with this on on low number of supporting mods and im aiming atm for just 220kw once i get FMIC on without EMU which comes soon after

realistic?

[GunMetalR33]

sorry i forgot to add that my gt30 came from horse power in a box.com.au morrie is a top bloke to deal with. but it had a gcg turbos sticker on the compressor cover so id say say they have some sought of arrangement going on.

I have a turbo from hp in a box as well and no complaints here.

Mine is the 6 blade GT30 center with a .7 ar comp housing and a VG30 exhaust housing which I think is .8 or something????

it makes full boost by 4000 and should do 300rwkw with cams. I currently have 250rwkw with 17psi and no cams.

Again, Morrie is a good bloke and easy to deal with.

[Roy]

So how much more boost are you going to run with the cams to make 300?

[discopotato03]

Mafia you'll have to refresh me , are your head and cams factory std ? Also yes those port shrouded comp covers do the RB211 (jet turbine) thing . Looks aside I think this was part of the reason HKS had the trumpet mouthed insert in their GT3037S comp housings .

The "lag" factor is why I'm going with the 52T compressor version and the .68 A/R GT3037 Pro S exhaust housing if I can find one . For what I want I think Garretts .63 may be a little small and their .82 a little big .

Forgot to add , Garrett don't make a T3 flanged GT30 based exhaust housing for the cropped turbine in your previous turbo .

One of the realities of the GT30 UHP turbine is its trim size - 84T , thats not exactly small and it was designed to have reasonably high gas flow particularly in mid and upper exhaust housing sizes . This is what it takes to get 500 Hp worth of airflow and exhaust into and out of this turbo . The turbo neither knows or cares if the engine can produce the gas flow , the head/valves etc have to pass the gas as well or its not going to happen . Divide 500 (Hp) by 2.5 (litres) and you get 200 (Hp per litre) which is getting up there for basically a production engine that put out just under 100 Hp/litre . To get user friendly wheel it round town power you have to do the sorts of things you'd do to the N/A version to make it breath down low - basically drag the dynamic CR up and have low pumping losses and reasonably high trapping efficiency . Its quite easy to see why Nissan went with the involved and expensive to produce multi throttle inlet system on the RB26 . Having this system allows virtual atmospheric pressure right to the inlet valves when they crack open at lowish revs . So it allows atmospheric pressue to charge the cylinders more easily than the single throttle type manifold can . Try one day watching your std boost gauge and note if its not on the middle peg before the turbo/s start to boost . If the pressure falls before the turbo/s spool up giving positive pressure then the engine is not getting enough atmospheric pressure driven airflow to feed the engine all it wants and so the dynamic or effective compression ratio drops . When it does there is a power dip or lull because until the hair dryer artificially pressurises the inlet tract the engines being starved of air . Better cams open the valves further and a little longer so greater "window" of opportunity for the atmosphere (or turbo) to charge the cylinders . Exhaust porting and more valve area means you lose less of the thermal expansion driven exhaust gas velocity that drives our low restriction turbo through inadequate port/valve/manifold capacity .

So shortish cams with safe extra lift , porting because the exhaust side needs all the help it can get , tuning because std its pretty soft and bent around emissions/noise/consumption and an exhaust manifold that works properly .

My long term plan is headwork/Poncams/HKS cast manifold and the turbo you already know .

With the real GT3071R yes , it needs the extra rotating assembly revs to do what the GT3076R turbos do airflow wise and even then its not the same effect . Compressor tip speed rises quickly with diametre so the centrifugal forces give a different effect . From the maps the mid trim GT wheels seem to give the best compromise of airflow vs adiabatic efficiency (heat rise) so thats where I try to be . As far as innertia with the GT30 turbine goes they are reasonably light for their vane area , possibly the greatest difference between it and the GT28 NS111 turbine is not only diametre (59.9mm vs 53.85mm) but blade count (10 vs 9) and trim size (84 vs 76) . This is why I think Garrett is very silly not giving us the 60mm OD version of the NS111 turbine , I put this to one of the Garrett engineers in the US once and he said exhaust flow would be less with a 60mm NS111 vs our 60mm GT30 UHP turbine . I still think there's a need for it but perhaps the economics of producing a dedicated series of turbine housings to support it are not worth Garretts effort if millions of GT30's are still going out their door . So untill they do or produce a less than 84T version of the GT30 UHP turbine we are stuck with the continental divide between it and GT28 turbines with only compressor and housing A/R juggling to help span the gap . Getting the engine itself as good as it can be pays off power wise but it goes a bit beyond cheap bolt ons . Nothing new here . The obvious solution if you want high Hp is to start out with the RB26 top and bottom end because it has more of the things needed out of the box . Even then porting and cams is still a big help .

Always comes back to budget and effort/determination , cheers A .

Edited January 26, 2007 by discopotato03

[Dale FZ1]

I interpret this as saying once you target performance outcomes for a RB25 that is beyond the capabilities of a GT28 based unit, and want a GT30 that you should crack the engine open, look at porting, cams, and manifolding to make it all work together?

It would take some really careful thought and matching of parts to get an engine that can still respond down low while delivering the top end clout that all that heavy breathing hardware can provide. I recall some threads probably back in 2004 that indicated guys were doing the extra engine work once they were targeting beyond about 260-270 odd rwkW. Maybe they were onto something.

Hopefully Mafia's 0.63 housing will give a reasonable compromise for street use and the odd drag. Can't wait to see his thread updated, with pics

BHDave and al r33 can you add to this, especially re transient boost response? Are you running internal or external gates, and/or engine mods with those setups? This whole GT3076 thing is giving lots of food for thought.

[Busky2k]

If I was to choose, and it could be done for a reasonable $$ then it would be to use the GT3776 0.54 comp assembly with the 0.63 IW turbine housing. Fairly well matched for flow on both sides, and the comp flow map is available. Beats a lot of guess work.

Who is able to build a custom spec cartridge like this? GCG?

He has the compressor cover shrouds - http://cgi.ebay.com.au/GT30R-COMPRESSOR-SH...8QQcmdZViewItem

Anyone care to explain how a compressor shroud can decrease lag like he claims? Seems a bit weird to me...

[Pauly33GTS-t]

blac32... supporting mods now, are only full 3inch -> 4 inch turbo back exhaust with 600CFM magnaflow cat, air intake also. im doing the FMIC at around time after i put on turbo. theres no point in me getting a turbo i already had on there than the one i want. so ill be running stock boost with this on on low number of supporting mods and im aiming atm for just 220kw once i get FMIC on without EMU which comes soon after

realistic?

As I stated above, is this realistic? Can I run my new turbo on stock ECU on stock boost for around a week or so before my FMIC goes on and my EMU then a tune?

Need to know ASAP thanks, turbo is going on next week and speaking to ATS during this week.

[Tangles]

Highly recommend you talk to Pixl8r, he went down the EXACT SAME path as you (with a S2 Stagea). 1st mod was the GT30 turbo from ATS due to blowing the original.............

[discopotato03]

The GT3776 uses the same 52 trim 76.2mm GT37 family compressor as the GT3037S/GT3076R 52 trim . But the wheel uses different backspacing in a GT bush bearing cartridge than a GT ball bearing cartridge . You would most likely need at least a custom backplate to set the housing in the right place in relation to the comp wheel . If you really wanted to go down that road a .50 A/R TO4E housing properly profiled would be much easier , could also get it drilled and slotted if its the big or 100mm (4") inlet boss type housing . HKS make their own custom .50 A/R port shrouded compressor housing for the GT3037 Pro S .

Difficult to see how that trumpet mouthed insert would drop the turbos boost threshold 500 rpm , the ported shroud helps but dunno about the insert . I don't recall people saying that the HKS GT3037S shrouded turbos scream too much but everyone says the port shroud housings do this in std form . I guess the wheel inducer tips turn pretty fast and the narrow slot is a good exit for high speed gas and sound waves . We need someone with an original insert to measure it up because 150 sounds exy for a piece of machined aluminium though the sections that have the grub screw holes may have been milled so a bit of time involved . I think the inner side of the boss is tapered on those Garrett housings so if it were turned parallel mounting the insert would be easier with cut setions of the right diametre and thickness aluminium tubing . The section near the wheels inducer has a nice groove to centre and seat the insert .

Dale what I mean is that doing the head work makes a very real difference to an other wise bog stock engine including the factory camshafts . This means an otherwise std engine not std cars IC/ECU exhaust etc . That car gets full boost from its STD turbo/manifolds at 2000 rpm with good fuel and tuning .

I believe its possible to get very usable road car power from making this an early mod because I think the power can be made with less extreme external bolt ons . I also think its a step in the right direction because what most of us want is not what Nissan intended the thing to do . You can force low boost torque out of any engine with smalish turbos but you pay the penalty higher up the rev range . Better to get all the low/med engine performance possible and then enhance it with the turbo IMO , atmo charged torque first then turbocharged torque second . An engine thats only any good on boost leaves a lot to be desired IMO , it makes people want boost from low revs and as we know you can't have it right down low and right up high , physical impossibility for a rotary compressor to charge a piston pump over a wide speed range when driven by its exhaust gasses . Compressor capacity and efficiency is not linear and neither is the turbine sides abilities .

Just on VATN or variable area turbine nozzle turbine housings . They are not a completely free ride . Ensuring the gas speed through the turbine blades is enough means there WILL be some turbine inlet pressure (backpressure) . Depending on how the wheels are sized they can give a good average ratio but will never be as good as a conventional turbo designed to work in a very narrow or single engine speed range . They are still a compromise limited by a rotary compressor and its fixed gas path .

Anyhow Trooper here is the one to ask about the GT3037S/GT3076R's real world experience because I'm pretty sure thats what he has (according to one source) but still to be confirmed . From memory he said ~ 270 Kw , starts to get some positive pressure ~ 2600 revs and gets busy quickly from 3000-3300 up . I think it was run to 18 + lbs boost with the tuners choice of 98 oct PULP . Turbine housing is supposed to be a Garrett GT30 .82 A/R IW type on a std manifold with a spacer plate to clear the comp housing . Anyhow ask him what he thinks of it .

Cheers A .

Edited January 26, 2007 by discopotato03