[diesel_john]

Above 20 to 1 you are at the point of diminsihing returns. About all there is to gain is taking off your muffler and using the turbo as a muffler. Even with a modest boost of 6 or 7 psi. Your cylinder pressures will be up in the considerably reduced reliability range. What happens is without oil cooled pistons increase intake temperatures reduce the strength the pistons and the increase pressure pushes a hole in the center of the piston. Turbo'd engines have a feed back loop to the injector pump to provide more fuel as more air is delivered so the power gain is not free. A cold air intake at a high pressure area for the intake and the cooling air would be worth while. Also exit the exhaust and heated air to a low pressure area. Propane injection has the effect of advancing the timing and also raises peak pressure. There are undeniable safety concerns with propane on board. You can produce this same effect somewhat by advancing the timing, but with more NOx. Biodiesel burns enough cleaner that just 10% reduces noticeable smoke from my 1983 engine. The only problems that i have encountered with vegetable oils is low temperature waxing and it tends to soften rubber seals in the fuel system. Biodiesel and vegetable oils are two different fuels, biodeisel is engineered to use in diesels, vegetable oils could be anything from bees wax to olive oil.

The reason i asked about frequency is the torque peak of most high speed diesels is below the 60 Hz required for house current. The diesel does not lose efficiency as fast as a gas engine does at rpm's below the torque peak. So you could have the advantage of being able to reduce the engine rpm down below the torque peak or even lower if the cooling fan will provide enough air. This is huge. This like having an infinitely variable transmission, this is very good. You can reduce "rack" and still fully load. Anyway, because diesels have a comparatively long stroke, piston speeds at high rpm's tend to reduce the life expectancy.