HTA3076 VS GTX3076 help
Got my GTX3576r on order 
Feb 22, 2012, 01:34 PM
#47
Please explain why the GTX3071R can be written off on the EVO?
Just my opinion, but the GT30 turbine wheel is pretty much done by 600 WHP no matter what compressor wheel you put on it. The HTA76mm wheel has been reported as flowing 59 pounds/min, the GTX71mm wheel flows 58 pounds/min and the GTX76mm flows 64lb/min. The HTA76 and the GTX71 are marginally on the low end of flow for this turbine. The GTX76 has excess airflow available and in some conditions (high altitude and high temps), the 76mm will come out on top on power due to the reserve airflow capacity. But unless you are pushing it hard constantly, you aren’t going to notice this difference.
The GTX71mm wheel has a backplate diameter of 71m where the HTA76mm wheel is 5mm larger. The GTX and HTA wheels both have extended tips to them so the inertia difference there is negligible. The HTA has 7 full height and 7 half height blades where the GTX has 11 full height, which is a lighter design? No Idea there.
Both are designed for high pressure ratios and I believe favor high shaft speeds.
Just My opinion here. On the dyno, the charts would probably lay right over each other, but I would guess the GTX wheel has slightly lower inertia then the HTA wheel and it should have slightly better transient response.
David Buschur said the HTA3076R was the best street turbo he's driven. The GTX3071R looks to be just as capable but potentially offer even better response. So again, how can anybody write off this turbo?
Is it because you followed Jeff Perrin's thread where he wrote it off without ever testing it and slammed it left and right? He based his assessment off the GT3071R vs the GT3076R where the 71 showed “only” about 200 RPM better spool on the dyno but the 76 KILLED it on power. Look at reality here though, the GTX71 now has more flow capacity then the old GT3076R so it should easily BEAT the power of the old 76. If it can match the old GT3071R spool, then it will actually beat the GTX76 by about 400 RPM.
Also, if you listen to guys that actually raced with both, in racing that requires throttle modulation and turning, every team I’ve seen using the GT30 stuff has loved the GT3071R and specifically said the 71mm wheel provided considerable response gains over the 76mm version.
Dynosheets aren’t everything...
Oh... and isn't there a Garrett engineer posting in this thread sugggesting the GTX3071R???
Just my opinion, but the GT30 turbine wheel is pretty much done by 600 WHP no matter what compressor wheel you put on it. The HTA76mm wheel has been reported as flowing 59 pounds/min, the GTX71mm wheel flows 58 pounds/min and the GTX76mm flows 64lb/min. The HTA76 and the GTX71 are marginally on the low end of flow for this turbine. The GTX76 has excess airflow available and in some conditions (high altitude and high temps), the 76mm will come out on top on power due to the reserve airflow capacity. But unless you are pushing it hard constantly, you aren’t going to notice this difference.
The GTX71mm wheel has a backplate diameter of 71m where the HTA76mm wheel is 5mm larger. The GTX and HTA wheels both have extended tips to them so the inertia difference there is negligible. The HTA has 7 full height and 7 half height blades where the GTX has 11 full height, which is a lighter design? No Idea there.
Both are designed for high pressure ratios and I believe favor high shaft speeds.
Just My opinion here. On the dyno, the charts would probably lay right over each other, but I would guess the GTX wheel has slightly lower inertia then the HTA wheel and it should have slightly better transient response.
David Buschur said the HTA3076R was the best street turbo he's driven. The GTX3071R looks to be just as capable but potentially offer even better response. So again, how can anybody write off this turbo?
Is it because you followed Jeff Perrin's thread where he wrote it off without ever testing it and slammed it left and right? He based his assessment off the GT3071R vs the GT3076R where the 71 showed “only” about 200 RPM better spool on the dyno but the 76 KILLED it on power. Look at reality here though, the GTX71 now has more flow capacity then the old GT3076R so it should easily BEAT the power of the old 76. If it can match the old GT3071R spool, then it will actually beat the GTX76 by about 400 RPM.
Also, if you listen to guys that actually raced with both, in racing that requires throttle modulation and turning, every team I’ve seen using the GT30 stuff has loved the GT3071R and specifically said the 71mm wheel provided considerable response gains over the 76mm version.
Dynosheets aren’t everything...
Oh... and isn't there a Garrett engineer posting in this thread sugggesting the GTX3071R???
Feb 23, 2012, 03:14 AM
#48
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Basically, the GT3071R got a bad rap on here because its compressor could not flow much more than an Old School Green. So, probably he is still identifying this new GTX version with that brick.
The GTX 3071R is a different animal however. It has a proper compressor wheel that moves about 57 lb./min. This looks to be a great upgrade for a stock block 2.0L engine as the compressor flows essentially almost as well as an FP Red. Which begs the question as to how it would stack up directly against the BB Red.
The GTX 3071R is a different animal however. It has a proper compressor wheel that moves about 57 lb./min. This looks to be a great upgrade for a stock block 2.0L engine as the compressor flows essentially almost as well as an FP Red. Which begs the question as to how it would stack up directly against the BB Red.
Last edited by sparky; Feb 23, 2012 at 03:58 AM.
Feb 23, 2012, 09:18 AM
#49
Well, I can tell you where I put my money...and why I have some bias here...
GTX3071R
I do wish Garrett would update the GT30 turbine wheel though to something like the GT28 design. Maybe it's just me, but the NS111 wheel seems like it's got better aero, is lighter and it looks like it flows like crazy in comparision to the GT30. Despite having ~25% less outlet flow area and being 6mm smaller on the major diameter, it only flows about 10% less then the GT30 wheel.
GTX3071R
I do wish Garrett would update the GT30 turbine wheel though to something like the GT28 design. Maybe it's just me, but the NS111 wheel seems like it's got better aero, is lighter and it looks like it flows like crazy in comparision to the GT30. Despite having ~25% less outlet flow area and being 6mm smaller on the major diameter, it only flows about 10% less then the GT30 wheel.
Last edited by 03whitegsr; Feb 23, 2012 at 09:23 AM.
Feb 23, 2012, 11:13 AM
#50
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I haven't seen any good Evo results with the GTX3071R, but I certainly hope you have better luck with your turbo than I had with the old 3071.
l8r)
l8r)
Feb 23, 2012, 01:48 PM
#52
I think it has as much potential as any GT30 based turbo can have. I don't think the GT30 turbine wheel is any good if you are after big power on low octane fuel. The turbine wheel doesn't seem to flow that well and the turbo needs a decent amount of boost to make power.
If I wanted a high power street evo that could make power on crappy gas and had reasonable response, I'd get the GTX3576R. The GT35 turbine wheel helps considerably with power for a given boost level. Also, chart it out, the GT35 turbine wheel in the 0.63 housing still flows as well as the GT30 in the 0.82A/R housing. Benefit though is it is going to spool faster and have a higher efficiency. The surge line is concerning with the GTX3576R though...
As far as potential of the GTX3071R. There is a car on the stock block, head, manifold, TB, intercooler piping and some 272 cams, full interior, running 10s on the ATP GTX3071R. That turbine housing looks FAR from ideal...
If I wanted a high power street evo that could make power on crappy gas and had reasonable response, I'd get the GTX3576R. The GT35 turbine wheel helps considerably with power for a given boost level. Also, chart it out, the GT35 turbine wheel in the 0.63 housing still flows as well as the GT30 in the 0.82A/R housing. Benefit though is it is going to spool faster and have a higher efficiency. The surge line is concerning with the GTX3576R though...
As far as potential of the GTX3071R. There is a car on the stock block, head, manifold, TB, intercooler piping and some 272 cams, full interior, running 10s on the ATP GTX3071R. That turbine housing looks FAR from ideal...
Last edited by 03whitegsr; Feb 23, 2012 at 01:56 PM.
Feb 23, 2012, 04:47 PM
#55
If that line is based on the peak efficiency points, mean efficiency, low, high, whatever, it's probably safe to assume it is consistent. If the GT30 wheel in the 0.82 A/R housing says it can do 23 lb/min at 3:1 and the GT35 in the 0.63 A/R can do 23, it is fairly safe to say they are going to have similar backpressure when maxed out.
Empirically, very few GT30 cars make great power on low octane fuel. They do just fine on higher octane fuel where boost can be cranked up though. GT35s on the other hand are the poster child of pump gas power, tons of great examples are available. Your car is one of the few that has made good power on that turbine on pumpgas. Maybe there is something to that whole twinscroll thing...
Last edited by 03whitegsr; Feb 23, 2012 at 05:15 PM.
Sep 3, 2012, 10:57 AM
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Sep 3, 2012, 09:06 PM
#60
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W00t I never knew that, what an awesome development! On that bombshell, which turbo manufacturer will be the first to throw away all their compressor wheel variations in favor of just putting 133mm compressors onto every turbine wheel they have to cover different power and spool requirements?