Time for a Reality Check. The 6.5 diesel engine equipped with a Asthma Attack GMx turbo is not going to deliver better MPG over the same or higher HP/TQ gas engine.
So you have ARP head studs in your quest for more boost? 14 PSI is the redline for the GMx turbo's. After 14 PSI they generate more boost by heating the air vs. more volume. Then the turbo is way off the compressor map running over redline RPM risking going "BOOM!". Altitude and boost creep takes a turbomaster set at 12 PSI sea level to 14 PSI at 8000' altitude. The back pressure is extreme as well when you push the GMx by holding the wastegate shut. Back pressure, aka exhaust restriction, means hot exhaust heats up the engine and requires the power sucking cooling fan to scream while your MPG hits the floor around 7 MPG. More boost gets you more power, but, the awful single digit MPG stays the same. On some grades towing with the GM3, that I tossed as scrap metal, I wonder if I hit GPM, Gallons Per Mile. KY isn't the Rocky Mountains, but, the hollers ain't exactly flat neither.
At this point with the GMx Asthma Attack sucking fuel and robbing the engine of any power you may as well sell the diesel engine and drop in a cheaper 454. Gasoline is cheaper than diesel esp. at nearly the same MPG. Seriously with a budget the MPG dealing with the GMx turbo on a areodynamic brick is going to be so bad that you should re-consider the powertrain choice. 6.0 Gas is better than a 454... Sorry that you are removing a gas engine and may find out this effort is for nothing but a higher overall expense and less reliable powertrain.
Otherwise pay now to get a better turbo in there on the 6.5 or pay later at the pump at every gas station you can't pass. Turbo exhaust housing being too damn small is not solvable by a wheel alone.
So you have ARP head studs in your quest for more boost? 14 PSI is the redline for the GMx turbo's. After 14 PSI they generate more boost by heating the air vs. more volume. Then the turbo is way off the compressor map running over redline RPM risking going "BOOM!". Altitude and boost creep takes a turbomaster set at 12 PSI sea level to 14 PSI at 8000' altitude. The back pressure is extreme as well when you push the GMx by holding the wastegate shut. Back pressure, aka exhaust restriction, means hot exhaust heats up the engine and requires the power sucking cooling fan to scream while your MPG hits the floor around 7 MPG. More boost gets you more power, but, the awful single digit MPG stays the same. On some grades towing with the GM3, that I tossed as scrap metal, I wonder if I hit GPM, Gallons Per Mile. KY isn't the Rocky Mountains, but, the hollers ain't exactly flat neither.
At this point with the GMx Asthma Attack sucking fuel and robbing the engine of any power you may as well sell the diesel engine and drop in a cheaper 454. Gasoline is cheaper than diesel esp. at nearly the same MPG. Seriously with a budget the MPG dealing with the GMx turbo on a areodynamic brick is going to be so bad that you should re-consider the powertrain choice. 6.0 Gas is better than a 454... Sorry that you are removing a gas engine and may find out this effort is for nothing but a higher overall expense and less reliable powertrain.
Otherwise pay now to get a better turbo in there on the 6.5 or pay later at the pump at every gas station you can't pass. Turbo exhaust housing being too damn small is not solvable by a wheel alone.
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