I'm still waiting to see a heads up side by side comparison of the ATT and HX40II clone on the same vehicle with all the variables except for the turbo constant (ie: same air filter set up, exhaust, injectors, tune, ambient conditions). A tow test with the same weight trailer up the same grade (the difference between a 75* day and an 80* day are negligible, but between a 65* and 90* day are) for IAT, EGT, boost, elapsed time and MPH from standing start to top. 0-60MPH times for uphill tow, 40-60MPH and 60-70MPH times on the level towing (simulated passing on highway). Unloaded MPG testing over same city/hwy road course of 90-150 miles (for accuracy) as well as a steady-state Interstate MPG test over 100 miles at 75MPH with all the measurable parameters recorded such as IAT, EGT, Boost at what RPM's over the courses.
In short, a scientifically and statistically valid, repeatable controlled experiment, something of which Diesel Power has yet to actually come close to doing, although they did come very close in the just out September issue in testing all of ATS's turbos on the same Dodge Cummins vehicle over a long-term testing period with the only variable being the turbo. They ran the stock HX35, then the S3000, S4000, S5000 and then the compound S5000 kit. Very interesting results, but very scientific method weak, as is most everything Diesel Power does, because they have JOURNALISTS testing products, NOT people with strong SCIENCE backgrounds who know how to set up a controlled experiment and what variables to control and parameters to measure.
Dennis, I understand exactly where you're coming from and the issues that you cite. We both also know and realize that the ATT was arrived at using much the same scientific methodology and testing as what goes into OEM or good aftermarket product development, yet the ATT was developed with much the same inspiration, research, fabrication and perspiration as those who are trying to do it themselves with the clone HX40II or other turbos like the VVT35 off the 6.7 Cummins. We are all looking for that better mouse trap to make the 6.5 a motor that can earn some respect and be competitive with the stock new generation Duramaxes/Cummins/Strokes.
Me personally, I am in the quest for the ideal set up of gearing/tune/injectors/turbo so that I can run at 1700-2000 RPM at 75-85 MPH on the Interstate and achieve a repeatable 23-26 MPG in my 4L80E '98 K2500 Suburban. The turbo is a key element in that equation, as the more air I can get into the engine (with minimal to no backpressure) so that I have complete burn and the coolest possible EGT while cruising will give me the best MPGs, all other things being equal. I'm not looking to be towing a 10K load up Deadman's Pass at 3600RPM, or spinning 350rwhp or making speed runs at 130MPH, but I want to stretch my cruising range and MPG's to the max. I'm also VERY seriously considering mounting a 32 gallon (actually 36 if you REALLY top it off) pickup fuel tank along the frame rail so I can get 78+ gallons of fuel capacity with the Burb's 42 (44) gallon tank so that I could be able to run Lincoln to LA without refueling in theory (I-70 through CO and UT kinda kiboshes that) or Lincoln-San Fransisco in reality, or Lincoln to pretty much anywhere on the Eastern Seaboard without refueling. My quest is for the ultimate Family Truckster Vacation and Screw Stopping Road Trip Vehicle. If I run on home brewed Biodiesel my cost for fuel would be about $0.04/mile, on waste ATF $0.00!!:thumbsup:
Even if I had to blend with pump diesel, my cost per mile would be damn cheap to say the least to make the run from Lincoln to Happy Valley and back for the Nebraska-Penn State football game (although in light of recent events, it probably won't be much of a game for the next decade) or to make the run to SoCal to visit my family and friends there, or perhaps to the ancestral grounds up in Portland, Maine to catch the fall colors, or maybe to the Florida Keys to see the sun set once again at Key West and then watch it slowly disappear as the sea rises due to Global Warming and the melting of the polar ice or maybe I just want to be a tight-ass bastard in my old age and only have to fill up once every couple of months for damn near free driving around town.
Sorry for the partial hijacking of the thread, but I thought the point of this thread and forum was the exchange of ideas on ways to make our 6.5's run better, be more efficient, last longer, be more powerful, etc.
