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Ok first link to a GTX thread over at Evolutionm.net .

http://forums.evolutionm.net/evo-engine-turbo-drivetrain/530822-compressor-wheel-design-garrett-gtx.html

And from NASIOC .

http://forums.nasioc.com/forums/showthread.php?t=2034214

There may be threads on one of the Supra Forums boards but haven't had time to look .

A .

Edited by discopotato03

gtx3076r with the skyline .73 AR exhaust housing (avoturbo.com) might be very interesting.....

currently using this housing with gt3076r bb core, lag in awd auto stagea until just over 2000rpm then it takes off! easy 250awkw with 450cc S15 injectors

better than stock automatic torque converter would change this again tho....

throw in 550cc injectors and the gtx3076r turbo and there's an easy 300awkw on pump gas with remap

unlikely you'll make 50rwkw more with a IW .73 housing, sure the comp side will flow more than that but you'll be limited by the exhaust housing.

like i said earlier in the thread i doubt anyone will see anywhere near the full difference on anything other than the 1.06 housings with a 3076. only talking about peak power tho

gtx3076r with the skyline .73 AR exhaust housing (avoturbo.com) might be very interesting.....

currently using this housing with gt3076r bb core, lag in awd auto stagea until just over 2000rpm then it takes off! easy 250awkw with 450cc S15 injectors

better than stock automatic torque converter would change this again tho....

throw in 550cc injectors and the gtx3076r turbo and there's an easy 300awkw on pump gas with remap

No offence intended, however I believe this would be a horrible setup.

I think the AVO housing is a fantastic idea for GT2871 52T to make a GTRS competitor, however I believe the housing too compact to take full advantage of a GT30 sized turbo (especially with 500+ HP of flow). Personally the most I would run through one would be a 3071 core with a T04B front cover, however I do think that also would be a great option.

Keep in mind that a GTX3076R has more flow than a 3540 on paper, it essentially is the replacement to the 35R. Ofcoarse the debate at hand (which is yet to really fire up) is will they really push the extra air while being as responsive as their predecessors. I will save my opnion for now as I am still pondering, however it was said in another thread that similar tech was applied to trust turbos some time ago with negligable results (not sure if it was simply a billet wheel or if the wheel was milled deeper and with different blade design as these are). It really is very hard to compare a GTX to an older GT knowing the only similarity to the older wheel is the OD.

Food for thought.

I agree that using these wheels in highflow applications will not yield the results that the compressor is capable of so you in effect have all the lag but none of the power associated with a large compressor.

The question that you ask is the question that is on every ones lips, and i think the answer will be that they will be laggier. I can't see how they can be more responsive (even with the billet wheel) and by the looks of that 522hp graph it looks like full boost was around ~4800rpm (judging by the torque curve). Now i would assume that it is running a large rear housing but that is in no way responsive in my book. I'm also wondering (with the X3071) how much of the gains are due to the different design and how much is due to the increased trim.

I was going to run a TS X3071 on my CA but if your not getting full boost until 4800 on a 2.5 litre then i can only imagine what it'll be like on a 1.8 litre.

Edited by D_Stirls

The question that you ask is the question that is on every ones lips, and i think the answer will be that they will be laggier. I can't see how they can be more responsive (even with the billet wheel)

Well yes and no :)

Remember the days of going from bush to ball bearing etc.

There was equal amount of debate back then as to whether it was "better" or not.

Also look from say a T04E, to a comparative (in terms of flow/500hp), say a GT3076 - they are light years apart in reality.

I think with newly designed, billet wheels, there are certainly going to be some gains.

Not as signifigant are previously seen ones, but the GT series turbos are showing their age now at around the 10-14yr marker or so now.

Stands to reason there would be new developments/tech that should improve things when going to the GTX series.

Yes the comp maps look excellent. However the results will be in back to back tests when someone swaps a GT with a GTX of the same stature.

I'm still on the fence, however the theory certainly suggests the results should be interesting none the less.

The problem with then is that it isn't a completely new turbo it's just a compressor wheel, the talk now is that the X3076 is now a miss matched turbo and you can see why as the turbine wheel is the same and now has to power a 115hp bigger compressor wheel, and it take shaft power to move air regardless of the lower inertia, and the shaft power come from the turbine. The X3076R is basically now similar to a GT3082R as the compressor flows the same as the 82mm GT wheel and the turbine is a 60mm GT30 item.

Personally I'd be interested in seeing what the X3071R would flow in a lower trim.

Well I'm only guessing but I think if anything the X type GT3071R could largely replace the 56 trim GT3076R though top end could tilt either way I think depending on how close to a perfect match the turbo was to the complete engine/car package .

I personally think that the the 76.2mm 56T GT wheel or the 71.1mm X wheel are probably as far as the 0.60 A/R T04E compressor housing should go . The 76.2mm X wheel is getting into 82mm 56t GT40 compressor territory and may need the T04S comp housing which is std on most GT3082R and GT3582R turbos .

Really those 82mm GT40 compressors should be in GT40 compressor housings IMO and particularly the 82mm X compressor wheel .

I think a standard GT3582R could see off a GTX3076R partially because the turbine is larger but it's crying out for its native GT40 compressor housing . See its really a case of GT3582R's having big frame wheels in a small GT25BB center section and smaller wheel family housings (both sides) than is ideal for its wheels . It really needs the big shaft big frame center section and GT40 type housings to give its best . The reason they don't is the cost and packaging constraints because this kind of this would externally start to look more like a GT4088R unit .

From what I've seen most of Garrett's GTBB turbos grew out of spin offs of the HKS GTBB spec Garrett units and often they made changes to be different enough to get around HKS's intellectual property when marketing their own range . I think many of the changes were for the worse and thats why I think many of the HKS spec units work better than ones in Garrett's lineup - better dialed in .

The GT3082R sold by Garrett is a good example of what didn't work , its basically the same unit as the HKS GT3040R but HKS went small comp trim knowing that it would have a little more airflow than a 56 trim GT3076R/GT3037S . God only knows why Garrett went up three compressor trim sizes ie 50-52-54-56 to make a really piss poor miss match .

You could be mistaken for thinking that some turbocharger manufacturers are only really motivated to spend money on development when the competition starts turning out superior technology .

I think if the house of G's wants a future in single scroll aftermarket turbochargers they're going to have to do something about turbines and their trims . The GT UHP ones need to go up in major diameter and down in trim size to gain shaft power and gain response or at least not lose any response in the process . I reckon its the way to make torque over a reasonably wide range and starting reasonably early . Silly really because they had it worked out with the larger wheel spec TR30R turbos , wheel wise these are similar diameter wise to a 56T GT3076R/GT3037S , and didn't offer it to the public . 9 bladed 60mm 73 or 76 trim NS111 turbines and 10 bladed (5+5) compressors in 76.2mm 56 trim . Lightweight high speed responsive things that won in WRC Rally and with Audi at Le Mans .

From memory the smaller compressor spec ones were something like 69mm OD and possibly both sizes had two trim sizes . I've got specs for them somewhere and will look them up later .

Someone must know why these wheels didn't turn up in some GTBB turbos .

A .

Something that will disappoint bradsm87 and other people who instantly assume things will be better...

http://www.turbobygarrett.com/turbobygarrett/news/race_updates/Garrett_Fully_Machined.html

Edited by SimonR32

Something that will disappoint bradsm87 and other people who instantly assume things will be better...

http://www.turbobygarrett.com/turbobygarrett/news/race_updates/Garrett_Fully_Machined.html

Those ones have been around for ages. They aren't GTX wheels so with no wheel redesign, of course I wouldn't expect it to be instantly better. The GTX wheels have been designed to be CNC machined and not limited by a castable shape. Those billet wheels are made for extra strength and urability rather than extra performance which is why they used the exact same design as the cast ones with same blade thickness (stronger but same performance)

Edited by bradsm87

The GTX flow maps are different.

I assume they have updated the wheel design as well.

Forged, fully-machined compressor wheel featuring next-generation GTX aerodynamics

http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT30/GTX3071R_803712_1.htm

The GTX wheels have been designed to be CNC machined and not limited by a castable shape.

I think you will find that there is pretty much no limit to a cast shape, but CNC machining has limitations... You are getting it all wrong!

The GT UHP ones need to go up in major diameter and down in trim size to gain shaft power and gain response or at least not lose any response in the process . I reckon its the way to make torque over a reasonably wide range and starting reasonably early .

Interesting opinion here, as the HKS 2835 vs the Garrett 3071 is merely some cropping action. Obviously they have trimmed the OD and kept trim the same, yet have achieved the same goal.

I find that by results, the 2835 clearly gets higher shaft speed with less gas, and does not seem to limit total flow capacity. Seemingly opposite to the above theory.. Yet in my mind smaller trim (regardless of OD) would result in better response in most cases. Perhaps it could go both ways, and capability of each would be highly dependent on application (I use the word application in a very broad sense).

who is stupid? Me or him? haha

I think we both know the answer... nice one Trozzle :)

Did someone mention earlier that MHI/Trust played with billet machined comp. wheels? Any more info on that?

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