Well I reckon Garrett first is a business and has to operate like any viable one if it is to survive .

Machining compressor wheels from a billet of aluminium would make wheel development an lot faster/simpler cheaper than casting them . They can make minor alterations to the wheels form in as long as it takes to load different programmes and carve out the wheel .

You'd think that a rolled billet of aluminium would be a denser material with better properties that ally used in castings .

I also think that imperfections from the casting process would be more easily and reliably avoided in rolled material .

My take is that the superior material machined rather than cast allows them to produce wheels with less production and property compromises which is why they've gone this way .

As per the TR30R's , these are dedicated competition turbochargers with a few compressor and turbine options .
Common sense tells you that competition turbochargers are built up to a std rather than down to a market competitive price so its not surprising to me that for cost no object real race cars got the bets bits 10 yrs ago .

I'm still disappointed that Garrett hasn't offered the 60mm NS111 turbines from the TR30R series in their GT/GTX production turbochargers . RC did once tell me that the two 60mm NS111 turbines would flow less than the 60mm GT30 UHP turbines do but that doesn't alter the fact that 84 trim GT30 turbines aren't exactly the most responsive things at lowish exhaust flow rates . I put it down to their large 84 trim size and while it does make for reasonably high outputs from GT30 based turbochargers the smaller ones could be more responsive with smaller trim turbines .

One day everyone's going to wake up to the fact that its torque that is god not Hp or kilowatts and the road to monumental mid rage torque is not big trim turbines . For the record AFAIK 60mm NS111 turbines are available in 73 and 76 trims where the GT30 UHP is only in 84 trim .

I'd like to see the wheels from the 76T TR30R with the 76.2mm 56 T compressor option made available or even this turbine with the 71.1mm 58T GTX compressor wheel .

Lastly Garrett has also used the port shrouded 0.60 A/R T04E compressor housing on the GTX 3071R - same as what they normally use on what you people call the GT3076R and HKS GT3037S turbos .
Higher capacity wheel in a larger A/R and with PS to avoid compressor surge .
I'm sort of surprised they haven't used the port shrouded version of the 0.70 A/R compressor housing on their GTX3582R to avoid issues when people put small A/R turbine housings on them .
I hope everyone's realised that GT/GTX3582R's appear to have bored out GT30 turbine housings on them rather than the GT40 turbine housing the real or larger framed GT35 OE diesel turbos have .
From what I've seen the first GT35 small frame GT BB turbo was the HKS optioned "GT3240" turbo , turbine appears to be a GT35 UHP cropped back to GT32 dimensions . HKS only ever used bored out versions of their T25 flanged GT30 turbine housings on them .

Good things from Garrett but they can't afford to rest just yet because other aftermarket turbocharger manufacturers are coming up in the world as well .

I reckon they want to think very hard about twin scroll twin integral wastegate turbine housings because this done well is VERY effective - just ask Mitsubishi about OE Evo turbochargers .

Still interesting times , cheers A .

Merry X mass as well .

 

Garrett does have their bolt-on Evo X turbo.... and those turbine housings flow MUCH better than the stock MHI turbine housing.

 

$ <----

 

link to results?
GTX3076 should be able to flow enough for 550-570whp

 

It was always going to be easier with a clockwise rotation OE turbo for the 4B11T engine because thats what most Garrett GT BB turbos are . I believe the exception is the GTP38R which from memory is an aftermarket turbo for a Ford Diesel pickup .
Those turbine housings for the Evo 10 were not without their issues for a while but I believe the drama was fixed .
I don't expect to see reverse rotation GT3071R's/GT3076R's though making the comp wheels from rolled bar would be easy enough .

I guess Garrett would have tested compressor housing options for the GTX3076R and GTX3582R but I'm mildly surprised they didn't go up a family of housing in each case , surprised because of the extra compressor wheel capacity . A GTX3076R could easily wear a T04S 0.70 A/R comp housing and with a bit of mucking around Garrett could surely machine up adapter rings to get GT40 compressor housings on GTX3582R turbochargers .
What you have to remember is that it isn't just the volute that changes in size its the diameter of the comp housings diffuser section as well .
The T04E series housings were designed with 76mm T04E wheels in mind and the larger T04S ones were also native to 76mm diameter wheels .
From what I've seen GT40 compressor housings are std on turbos with 82 or 88mm diameter comp wheels which is GT40 territory .
Also note that HKS at times cast larger diameter diffuser sections into their custom compressor housings and a good example is the HKS T04Z compressor housing .

As for turbine lag it will be interesting to see back to back tests of each GT and GTX unit , interesting to see if they can have extra pumping capacity and how much the port shrouded housings and lower overall blade count (11 vs 12) affects the load balance on the turbines .

A .

 

where?

 

its on a subaru, but it should still give you an idea. spool and power seem to be where a standard 35r would be, but the little turbine wheel will kill power on race gas.

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

 

That's not a true Garrett wheel. It should be obvious because this guy had it back in August and the GTX3076 only just made it out like last week.

A few other things. A true Garrett GT(X)3076 size turbo, and the 3071s, use those small 12-point nuts. This has a 6-point nut on it. Look at the size of the hub, it looks massive compared to the real GTX wheel. Lastly, look at the machining of the compressor housing; all Garrett 3076 currently have that step machined in right before the compressor wheel (I dug around on some Austraila forums and it turns out its for HKS to bolt in their bellmouth thing). The picture of the turbo this guy has does not have the step in it, so it's some custom machining.

 

you should post over there to clear up the misinformation.

 

HAHA

thats like telling the Honda-Tech.com Guys they are wrong also

 

i posted his quote over there. one of the most reputable builders/tuners liked the info.

 

yes i read the ONE quote also from the many builders/tuners also.

Great detective work

 

supposedly a 3076gtx on a 2.0 long rod evo 8.

http://bbs.22b.com/cgi-bin/ultimateb...9;t=002010;p=2

 

I'd like to see a new mid frame option from Garrett. Something like a 65-67mm compressor matched to the GT28 turbine. I would think a compressor that size could be produced in the 45-50 lb/min range and the GT28 turbine in a larger A/R housing could keep up.

Basically a quicker spooling replacement for the GT3071R.

 

No mate, i know the car and it's a blouch gt30 xt-r