This is from ATP's page (not from the EVO kit but from their turbo page):

GT3071R
Turbine
-Wheel: 60mm w/ 84 trim
-Housing: .63 ar, .82 ar, 1.06 ar

Compressor
-Wheel: 71mm w/ 56 trim
-Housing: .50 ar

GT30R
Turbine
-Wheel: 60mm w/ 84 trim
-Housing: .82 ar, 1.06 ar
-Maps

Compressor
-Wheel: 76.2mm w/ 56 trim
-Housing: .60 ar

The turbine wheel is identical but the compressor wheel is larger on the GT30R as well as the housing which is .60 a/r. This last part is what makes the GT30 spool slower but produce more power.

I already have a custom made stainless "almost" equal length manifold with stock turbo flange that will go on the car at the same time as the new turbo.

I also changed the turbine housing to .82 a/r on my 3071 to allow some more exhaust flow. This will slow spool a little but together with my other mods I think it will be ok anyway

 

My kit will have the following supporting mods:

Motec stand alone ECU
Tomei 260 procams 11,5mm lift IN/EX
Tomei cam gears
Full 3” exhaust with test pipe
780cc injectors
ATP lower intercooler pipe
Custom made high flow stainless exhaust manifold
255l fuel pump
4” compressor inlet with 4" custom suction pipe

I think this setup hopefully will show some more of the 3071’s potential. Sad thing is that I will not have my car tuned on a dyno until end of July or beginning of August

 

thanks EVOVIII SWE, its all starting to make some sense i think!

Chris!

 

No problems, I actually found that page to be quite informative:

http://www.atpturbo.com/Merchant2/me...egory_Code=GRT

 

evoVII SWE,

what are your gear settings?

 

I have not yet installed the cams and the cam gears, they will be installed at the same time as the turbo which I'm still waiting for so no settings at all for the moment

 

so, is this said the gt3037 will made more HP than gt3071,so what is about the A/R for 0.63 or 0.82,is that mean if i order a gt3071 with 0.82A/R will made more HP than a gt3037 with 0.63 A/R???
and one more question ,the GT3037 with 0.63A/R and GT3037 with 0.82A/R is this will be made a same HP or will be diffrence

 

look man. I know what you are asking. I am the one who has the kit. I wont lie to you. If the kit sucked I would of called ATP names on this site all day long like I did with AL. the kit is great. Fit and finish I have never seen such a thing. best customer service( they over night 40lb box) with out charging me.

about the kit. Today I got full boost at 4300 rpm 23 to 24 psi pulling so hard the scares the **** of people on the streets. stock turbo gives you full boost at 3500 rpm that 800 rpm different. now remember i have stock cat which is killing my turbo and I have stock engine no cams not even intake. bottom line I can see my turbo spooling 300 rmp sooner when I get my test pipe installed next week. that leaves 500 rpm on the table. its your choice here to get cams and cam-gears and high flow manifold. bottom line. can i make my turbo spool like stock?? NO can I make it 300 rpm like ATP said? YES. Don’t go with a bigger turbo because I am making 390whp now around 500 whp sh it starts braking down. I am going to stop at 450whp and start buying rims and sway bars. it's you call but if want to see my car give me a call or pm me.

 

I just could not spend $5700 on hks turbo kit that comes with no DP and cracking manifold
I just could not spend $4500~ on AMS kit too much$
I just could not spend $2400 on br turbo kit on unwater cooled turbo that i can buy for $600
I just could not spend $4700 on greddy turbo kit that need some serious work
I just could not spend $3800 on works kit which is the same but I have one ECU software that’s it, no race software.
do you see where i am coming from?

 

you guys should come over here and see what people have to pay! its stupid.

chris

 

Well, I’ll try to answer this the best way I can, I’m no pro on this but I’ve learned a lot lately. To start with the 3037 will always be able give more peak power due to its larger compressor wheel, this is if you would compare it on the same car. The larger compressor wheel will also make the 3037 spool slower compared to the 3071 if compared with the same turbine a/r.

The size of the turbine wheel is the same on both 3071 and 3037 and you can choose the housing a/r of either .63 . 82 and also 1.06 I think. The difference here would be when the turbo starts to spool, the larger a/r you have the later it will spool, on the other hand you might avoid surge and reduce exhaust back pressure and due to that be able to run higher boost and thus get more power in higher rpms. You could say that you have a specific rpm band or interval in which the turbo is efficient and you just move that interval up and down the rpm scale, so if you go for a larger a/r (this is just an example) and say that you loose 500rpm spool in the bottom you gain about the same on top and the turbo holds on for another 500rpms.

Once again, I’m no pro, I might be mistaking but this is the way I’ve understood things, don’t forget that the world of turbos is a world of compromises as many other things but very obvious here

If anybody thinks that I’m wrong please feel free to correct me since I’m only trying to learn and understand as much as possible about this subject

 

Painful to read this thread. Lots of misinformation in here.

GT35R is also called GT3540. Same turbo.
GT30R has many configurations of wheels. GT3071, GT3037, are both GT30R turbos renamed to clarify which compressor wheel is run.
all GT turbos have the exhaust housing options 63. 82. 1.06. bigger is not necassarily better. but bigger always means laggier.
consult AMS, shiv, or ATP when deciding what a/r exhaust to run. they have done extensive testing on what works well.

 

So would you care to point out all that misinformation please? I can’t see anywhere where your stated examples are described wrong in any way?

 

Yes would you mind to tell us where are the misinfo master

 

Right-0. Same turbine side as the GT30R. Smaller compressor which slightly better speed match. Makes it more more slightly efficient at lower engine speeds. Slightly less lag and slightly less tendancy to surge. Especially with the anti-surge "collar" in the compressor inlet. I suspect the GT3071 gives up around 30-40bhp over the 30R when it comes to making max power. Some may find this compromise reasonable given the advantages. Others, with more lofty power goals, may find it unreasonable and stick with the 30R.

FWIW, one of my good friends was instrumental in both this turbo's configuration as well as getting this turbo to market. I've been hearing about it for nearly a year and it's nice to see it finally hitting the streets.

My 2c,
shiv