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

[The Mafia]

Was wondering where you were??? Seems like ur only hanging around in the rb30 threads these days

Can u comment a little more on the response of the .63 and if it felt like it was lacking up in the rev range

I would have like to see what ur set up would have made without wmi even though i will be using it as our best here is 95.... i just dont want to depend on it too much if u know what i mean

hehe sorry, been busy building my motor.

It just kept pulling, all the way to 7,000rpm. I don't think it had much more left in it though.

If going 100kmph, and you knocked the car back to third, youd start to fish tail.

Was fun

[Lithium]

lith, dont need vids of this, just experiences,

top gear, flat road, 80km/h, partial throttle accel. to 100km/h, how does the car feel compared to stock?

80km/h 4th gear up hills +100 km/h 5th gear up hills, how does the car feel compared to stock?

what I am getting at, is do you miss the "always on boost" nature of the standard turbo for just general partial throttle around town driving? Or does it make boost quickly enough when needed(overtaking, pulling out etc)

I find this a bit of a crazy question, its naturally quite a bit flatter than the stock turbo if you are pulling from low rpm and low loads - I'd hope you aren't disappointed to hear that because that'd be crazy. Any other turbo capable of over 270wkw is going to give you compromises here, too!

At anything over around 2000rpm and what I'd call "load" the motor will start making positive, just not as much as the stock one. I haven't specifically tested the things you are talking about there - for what its worth its not conspicuous enough that anything has stuck out. I do know I can cruise at 80kph up a hill in 4th and then if I wanted to overtake I'd be able to lean on the throttle and it'd start picking up quite happily. I do use 5th up some 80kph hills...

5th gear up a hill at 100kph isn't a problem either, though going up said hill you aren't going to get much acceleration at 1000kph if you decide you want to pick up some more speed.

The stock turbo is quite fun for blatting around town, I do remember it but I don't feel short changed by not having it - it just completely changes the nature of how the car drives etc. The stock turbo was a bit boring to drive, and everyone who has had a stock turbo R33 (From what I can tell) seem to find it huge fun in general.

The car is an animal for overtaking/pulling out etc, its much more rewarding overall to drive than a stock turbo - I have let a couple mates who have stock turbo RB25s drive my car and have had no complaints about the lag down low, it more than makes up for itself and in ways it really just makes the car feel less like a shopping car and more like a high performance thing.

Its worth noting the comment earlier by the guy with a stock twins RB26 - the car has less lag than a stock GTR. When you take into account the car is over 100kg lighter than a GTR, and no one complains about the driveability of those - you'll realise that it seriously is a really good street setup.

Edited January 10, 2010 by Lithium

[_Ryan_]

I find this a bit of a crazy question, its naturally quite a bit flatter than the stock turbo if you are pulling from low rpm and low loads - I'd hope you aren't disappointed to hear that because that'd be crazy. Any other turbo capable of over 270wkw is going to give you compromises here, too!

At anything over around 2000rpm and what I'd call "load" the motor will start making positive, just not as much as the stock one. I haven't specifically tested the things you are talking about there - for what its worth its not conspicuous enough that anything has stuck out. I do know I can cruise at 80kph up a hill in 4th and then if I wanted to overtake I'd be able to lean on the throttle and it'd start picking up quite happily. I do use 5th up some 80kph hills...

5th gear up a hill at 100kph isn't a problem either, though going up said hill you aren't going to get much acceleration at 1000kph if you decide you want to pick up some more speed.

The stock turbo is quite fun for blatting around town, I do remember it but I don't feel short changed by not having it - it just completely changes the nature of how the car drives etc. The stock turbo was a bit boring to drive, and everyone who has had a stock turbo R33 (From what I can tell) seem to find it huge fun in general.

The car is an animal for overtaking/pulling out etc, its much more rewarding overall to drive than a stock turbo - I have let a couple mates who have stock turbo RB25s drive my car and have had no complaints about the lag down low, it more than makes up for itself and in ways it really just makes the car feel less like a shopping car and more like a high performance thing.

Its worth noting the comment earlier by the guy with a stock twins RB26 - the car has less lag than a stock GTR. When you take into account the car is over 100kg lighter than a GTR, and no one complains about the driveability of those - you'll realise that it seriously is a really good street setup.

I guess what I was getting at- Do you find the turbo too big for a daily, and you have answered that with a no!

The stock turbo is too small for a daily driven car, always on boost etc, and it sounds like a 3076 never leaves you waiting for positive pressure.

[gotRICE?]

I was one of those Stock turbo'd R33 owners that has had the pleasure of multiple playtimes with Lithiums car, so will try give you my experiences.

1st time i drove it on the street, i was relatively nana for a while getting the feel of things, then once roads were clear etc had a good stab at it, and when your just out for a blat, it feels just as good (maybe a few 100rpm short) of the stock huffer at similar rpm.

On the open road and/or highways, my 1st impression was it felt a little "doughey" as Lith put it. As in, if you were in slightly heavier traffic, sitting at 80-100km/h in 5th, and wanted to take the gap in the right lane you spotted in your mirror. It felt to me like it wasnt going to get you there quick enough. So there were a few moments where i hesitated and didnt go for it.

There was discussion at this point, and Lith mentioned not having any problems doing the same thing so i had a little test in the slow lane. And to my surprise it does just 'go' when you lean on it. A tad more throttle than i would give mine, but it still works.

The problem i think i was having was that i was expecting response like the stock turbo would give at that point, and see lots off boost, quick.

Clearly with the bigger turbo it doesnt do it quite as rapid, but the car still does go for it. And being a bigger turbo, that 'kick' it gives, comes later because of where its starts to really ramp up. And as we know, the stock turbos kick has well gone by 3500rpm. So once i had felt what it would do it was not a problem to drive.

Driving around town its actually pretty nice too. Not constantly making boost where ever and when ever, BUT, if you want it, it is just hiding a cm or so further into the pedal.

The other tests, or more f**king around, was swapping cars at the last drag meet. Both on street tires. Both no practice in each others cars.

Lith got off to a blinding start, and me, still trying to figure out whether Liths "4000rpm and dump it or youl' bog" madness would work (clearly im still thinking stock turbos reaction), bogged only made 3500rpm... Oops.

Got back in it quick though. Made the boost through 1st, no skids. Missed 2nd (doh! not used to the puk), and ended up sailing past my own car as if it was standing still in 4th across the line. Was probly one of the closest and most exciting races of the day for me.

I think these situations are quite difficult to describe accurately over a forum TBH. Its def one of those things you need to try.

Am quite keen for another swapsydaisy after mine is tuned this month too Lith

[Lithium]

There was discussion at this point, and Lith mentioned not having any problems doing the same thing so i had a little test in the slow lane. And to my surprise it does just 'go' when you lean on it. A tad more throttle than i would give mine, but it still works.

The problem i think i was having was that i was expecting response like the stock turbo would give at that point, and see lots off boost, quick.

Clearly with the bigger turbo it doesnt do it quite as rapid, but the car still does go for it. And being a bigger turbo, that 'kick' it gives, comes later because of where its starts to really ramp up. And as we know, the stock turbos kick has well gone by 3500rpm. So once i had felt what it would do it was not a problem to drive.

Cheers for adding to that Mr Rice It reminded me of one of the sensations I have going from my car to a stock turbo car and back again. That "needing more throttle, but getting the 'go'..." sensation feels back to front when you go from my car to a stock turbo car.

When driving my car around, it feels to me like it does what you want - you give it half throttle, and it tries half hard. You give it full throttle and it gives you everything. If I jump into a "healthy" stock turbo setup, I am initially pretty impressed at low rev/low throttle behaviour - but then give it a bit more and it feels like it doesn't give me the extra bit of go I would expect for the extra bit of throttle.

To me, driving a stock turbo car (even below 4000rpm) it feels like going from 30% to 50% to 75% to 100% throttle doesn't give proportional increases in acceleration - like 30% feels like its going to be quite interesting then you go to 50% it tries harder, but not quite as much more as I'd have expected, so go for 75% and I almost feel like something is wrong with the car so go for 100% and its extra effort feels like a token more than committed effort.

[gotRICE?]

Then you need to wait for the VCT to do its thing for that little bit "extra" if thats what you call it

[juggernaut1]

For the sake of completeness to this thread (and for those who are a little more adventurous) I thought I would link an update from the ATP turbo website - which shows that Garrett has released off the shelf T3 .82 and 1.06 twin scroll V-band housings for the 3071/3076/GT35R range of turbo's. These housings compliment the existing .78 twin scroll v-band housing available for these turbo's.

Cost is US$395 for the .82 and 1.06 and US$295 for the .78.

http://www.atpturbo.com/

Cheers

Edited January 13, 2010 by juggernaut1

[Lithium]

Yeah had noticed that, thats very cool - if these options were around (and I know what I know now) when I first bought my GT30R I'd have quite a different setup now.

I drove the Skyline to work today and realised I cruise around everywhere in 50kph zones in 4th gear, and 4th gear accelerates me cleanly from 50-100kph - anything above 60kph and I build enough boost/torque to pull harder than the rest of traffic.... enough so I wouldn't want to lean on it if there was a cop around. It really definitely is quite useable, I'd love to know what a twin scroll .82a/r T3 setup would drive like!

[wolverine]

Would the flow of a divided 0.82 housing be equal to an undivided 0.82 ext gate housing? Does the divider cause some reduction in area or is that already factored into the AR calculation?

[JonnoHR31]

been wondering exactly the same thing. i know as a general rule you go a larger a/r with twin scroll but not sure if thats because of the greater efficeincy or a greater restriction

[GTScotT]

been wondering exactly the same thing. i know as a general rule you go a larger a/r with twin scroll but not sure if thats because of the greater efficeincy or a greater restriction

theoretically ud go larger as its more efficient and you could get extra power for the same spool.. yet thats theoretically lol.

theory vs actual results can often be negligible yet if the manifold was done right with a split pulse you could potentially get a great deal out of it.

[juggernaut1]

Yes the divider causes some reduction in the volume of the ex housing.

Not sure if I would mate a .82 divided to a 3076 56 trim compressor on an 2.5 litre RB.....but it would depend on engine specs though. I know Full-Race has used the 1.06 divided on a stroked Evo motor but the heads in those engines flow very well.

Moreover, the Garrett twin scroll bolt-on upgrade kit for the Evo X has a .94 divided housing with the 3076....however they have a unique footprint so may not be comparing apples to apples when comparing to a typical T3 housing.

[discopotato03]

Just to keep things in perspective "T3" turbine housings are designed to suit T3 cartridges and T3 turbines , there are other families of turbos using the T3 dimensioned mounting flange but thats often the only similarity .

What people call the twin entry T3 flange often only matches the stud/bolt hole centers and the total distance across the inlet ports is wider than a T3's single inlet port .

The reason why its good to go up in A/R size for the same capacity engine when changing from single to twin scroll turbine housungs is to take advantage of the lower pressure across the turbine housing on the manifold side . Because you now only have half the number of cylinders exhausting into each side half as often you want to reduce the resistance to exhaust flow out of the cylinders - increase volumetric efficiency .

Geoff Raicer found ages ago that it was possible to increase TS housing A/R , from the smallest size available , to somwhere about the middle of the range and get gains everywhere . I don't remember which engine , may have been a Honda and testing GT4088R's .

It would be nice to think that one day Garrett may make us a TS twin integral gate "T3" flanged GT30 turbine housing but we are a very small part of the aftermarket so difficult to get their R/D back .

Will also watching to see if they decide to make the GT30 and GT35BB turbos with the GTX compressor wheels . I'm not so much interested in the extra 10% airflow for the same sized wheel but a bit better compressor thermal efficiency can't be a bad thing .

Cheers A .

[phunky_monkey]

For the sake of completeness to this thread (and for those who are a little more adventurous) I thought I would link an update from the ATP turbo website - which shows that Garrett has released off the shelf T3 .82 and 1.06 twin scroll V-band housings for the 3071/3076/GT35R range of turbo's. These housings compliment the existing .78 twin scroll v-band housing available for these turbo's.

Cost is US$395 for the .82 and 1.06 and US$295 for the .78.

http://www.atpturbo.com/

Cheers

Pity these weren't released late last year Ian!

[juggernaut1]

Tell me about it....I've just had the .78 extrude honed....Lol.

[wolverine]

i would love to the see the before and after the extrude honing.

[juggernaut1]

i would love to the see the before and after the extrude honing.

Hmmm...we'll see as I was actually going to mate the extruded honed .78 straight onto a 52 trim 3076 rather than back onto the current 3071 setup. Souldn't be too hard though as I will have two .78 housings (1 standard and 1 extrude honed). However, Phunkey (Dane) has bought my std .78 and 3071 setup....so will have to run it by him first.

[wolverine]

That would be great if it is possible.

Would you have chosen the 0.82 housing for the GT3076 or the 1.06 housing if they had been available?

[juggernaut1]

As I have an SR I would have stayed with the .78 or .82 and matched the compressor accordingly for a good street/track package. If you did more drag then the 1.06 wouldn't be out of place on a 2 litre. RB's produce more low down torque as well so a T3 1.06 with 3076 56 trim would probably work well on an RB25 in most situations.

My purely speculative choice of turbo's/housings match would be as follows:

T3 .78 with 3071

T3 .82 with 3076 52 trim

T3 1.06 with 3076 56 trim

T4 1.06 with GT35

Edited January 19, 2010 by juggernaut1

[phunky_monkey]

Tell me about it....I've just had the .78 extrude honed....Lol.

For some reason I had a feeling this would happen, or the new range of GTX-R turbo's in the T3 flange would be released... oh well, not much you can do I suppose.

As for the testing of the 3071 with the extrude honed .78, I'd actually love to see the results too but I guess it depends on timing as I've sold my current turbo kit and my car will be off the road until the the 71 is ready to go. So I guess we'll see when we've got some more information on timing if that sounds ok?