About the exhaust: In theory, a turbocharger is more efficient because it is using the "wasted" energy in the exhaust stream for its power source. On the other hand, a turbocharger causes some amount of back pressure in the exhaust system and tends to provide less boost until the engine is running at higher RPMs.Michael Yount said:your statment "turbo.....doesnt rob the engine of any power" is incorrect. Of course a turbo takes energy from the engine to turn it. A supercharger takes it directly from the crankshaft via the belt-drive. The turbo acts as a significant restriction in the exhaust stream -- each time the pistons come up on the exhaust stroke they have to push harder than they normally would to overcome that restriction. As with the supercharger - the loss is worth it as you can net a power gain. But the turbo creates parasitic loss as well. Just to set the record straight.
That doesn't necessarily mean that the power loss increases during higher pressure due to the higher revs, right? Or does one exceed the other?Michael Yount said:With regard to system backpressures - they typically increase with increasing rpm and increasing exhaust flow.
Michael Yount said:85SS - there is no Santa Claus - your statement "turbo.....doesnt rob the engine of any power" is incorrect. Of course a turbo takes energy from the engine to turn it. A supercharger takes it directly from the crankshaft via the belt-drive. The turbo acts as a significant restriction in the exhaust stream -- each time the pistons come up on the exhaust stroke they have to push harder than they normally would to overcome that restriction. That's where the parasitic loss occurs. As with the supercharger - the loss is worth it as you can net a power gain. But the turbo creates parasitic loss as well. Just to set the record straight.
"Supercharger" is a generic term for any forced-induction compressor that is driven by a belt, gears, or a turbine. The turbine-driven version is known as a turbocharger, and it has the potential to be the most efficient power-adder for an internal-combustion engine on the planet. An internal-combustion engine is notoriously inefficient: Only about one-third of the energy released during combustion actually drives the crank. Of the remaining two-thirds, one-third goes into the cooling system, and one-third goes out the exhaust as heat. In fact, a 200hp engine dumps the equivalent of about 70 hp of raw heat straight out the tailpipe! However, a turbo's turbine-wheel is driven by the engine's own exhaust gases as they exit the motor, so some of the heat that normally goes to waste is now used to power a compressor that pumps more air into the engine.
Although a turbo's position in the exhaust stream does restrict exhaust flow potential to some extent, the pumping losses are much less than the parasitic drag induced by a conventional supercharger's belt or gears. In a typical gasoline-fueled engine, it's common to see 30 out of every 100 hp added by a beltdriven supercharger being wasted turning the drive pulleys and belts; this compares to about 5-10 hp per every 100 suffered as pumping losses by a typical well-designed turbo installation. Considered as a system, the turbo setup has less heat buildup than an old-style Roots blower, and its smaller size compared to a centrifugal supercharger permits higher compressor-wheel rotational speeds and more radical blade-tip curvature that collectively translate into greater pumping efficiency.
Dark Knight said:come on...
I'm going with 557 cubes, torque and HP all the time, then a 200 shot fogger for MORE power..