Originally Posted by dmaxstore
We will be running the LMM's factory single turbo with a possible twin turbo set up in the future. Our X80's V drive should be able to handle 450 ft lbs, however a different ratio will be needed to optimize the lower RPM. With a stock block and heads the Duramax motor is capable of producing around 650hp or 1200+ ftlbs with proper tunning and turbo's. This motor will not be tuned for max HP just max efficiency.
I'd super charge it and ditch the turbo. You have no air circulation for the intercoolers, you can't have water going through the turbo, and you can't install the water inlets post turbo or your manifold temps will be hot enough to melt things. Super charging it will be the best option for you in this case and fairly easy to do. The heat will be to great with turbos. Now for the exhaust, just straight pipe it with standard water manifolds and zero filtration. If you leave the engine on a stock tune, the amount of black smoke and emissions is low already. Pushing a prop you won't have near the load on the motor that it would in a truck. Also the gas manifolds and exhaust won't hinder the restriction of the duramax (IMHO).