Guys I was citing a specific example for one individual's need and also said in my 1st reply I mispoke, I'm not saying for everybody's need ATT is the best, put whatever dang turbo on there you want, best turbo discussions are same thing as best reflash discussions pointless; use whatever floats your boat.
Read the original replacement turbo thread, & from day one I have said this turbo matched with the 6.5 is a very suitable turbo and IMO the best one for overall normal driving, and heavy towing, some turbos will out accelerate it to a point, above 1500rpm the ATT is very stout. But it does so without boosting any more than the 6.5 was designed to operate at and a healthy 6.5 will be vastly improved overall with it over the GM-8.
With my GM-8 on my truck I required 11-12 psi on a given day to run +100mph, with my ATT I can run same with 8-10 psi on given day, my GM-8 required me to run an IC to tow big, my ATT at this point has not required it, I have removed my IC, and will be running WMI to control IAT, with a fully enclosed 6X12 trailer loaded to 2000# (lot of "sail area" on the trailer) I have not suffered without the IC nor defueled from high IAT. I'll have the WMI for when I tow really big later on 18K#, just in case I need to lower IAT, but from what I've seen thus far I doubnt I'll really need it or if I do I'll use it much.
My Suburban has neither IC or WMI, has defueld only once running 111 mph for test on 95F day, I could not do that with my GM-8.
Both the burb and the truck mpg has gone up, power has been retained, and by seat of pant dyno has more power overall. Others report similar finding with their ATTs.
I don't hit redline on the burb with 3:42s on a cool day because it runs out of fuel not boost, FTB has not been installed and OEM lift pump on it still, it just will not go any faster 3100 max rpm IIRC.
On the truck I don't have a safe place to try to redline it in OD 114mph is as fast as I've pushed it 3100 rpm too much traffic, and after last years axle shaft falling apart, I'm afraid of a tire blowing or something else going bad and me killing myself or someone else on the interstate.
Compressor wheel maps don't mean squat here I don't have a map of the ATT, nearest one to the ATT is a map for a Mitsubishi TDO-7 22A, which the ATT was morphed from, ATT does not have same compressor wheel as the TD0-7, and I'm not sure the turbo wheels are exact matches either.
I think it would hold it's own on same hill climb as RJ's and does not require that CR be lowered, (which at this point is conjecture) as it's not likely that one will run that hill anytime soon.
The simplicity factor is best over anything other than a GM turbo, mpg is better, power over stock is better, cost to install is lowest, unless one a other turbo in hand, I don't know fab cost of others, but that is with a used turbo and fabbing work, vs a $745 ready to install kit which IIRC is what Walking J is selling them for.
Hopefully one will be dynoed soon, couple of folks saying they will be dynoing theirs in the near future.
FWIW much as some folk have repudiated & surmised that I have a financial interest in the ATT, I've got nothing to do with the ATT other than helping Slim with the R&D and working out bugs in the kit so "my 6.5 brothers" get a good product for their 6.5s.
So I have no zippedy do dah care if you buy a ATT, or Holset, or RJ or Bubba's house of turbos on yours, ATT works, & works well bout all I'm gonna say bout it. To define the best would require study same truck diffetent turbos on dyno, or towing vs timed to climb or track time slip, and that mite lead some credence to the discussion, at this point it's supposition.
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