Originally Posted by black9D5
So I was reading the big debate of turbo vs sc on some forums today when a guy made a valid point in my opinion. He was saying that centris require 30-40 hp to run at top speed, roots require upwards of 60 hp to run at top speed. Then add anything that the crank has to turn( water pump, alternator, etc). So let's say you measure 500 hp at the flywheel. Then Add the hp the sc takes to run and accessories and then stated that the rods might be handling as much as 600hp. Depending on the parasitic losses. Then take drivetrain losses and subtract another 15%. So this means 425 rwhp turns into 600 hp on the rods. However a turbo at the same power level, an electric water pump and aluminum flywheel you could be seeing 575 flywheel hp and 490 rwhp. Basically the guy is saying that higher, safer hp numbers can be achieved with a turbo rather than a sc because the turbo doesn't steal any hp to make it run so the number on your dyno will be closer to what the internals are seeing. Changed my decision between a sc or a tc! Thought the guy had pretty good logic.
I'm not sure I can agree with the whole concept. It seems like when you try to calculate the stress on the rods by backing into the number, it's the same as adding bolt-on mods on top of each other to get a bigger increase. You can put an electric water pump and aluminum flywheel on a SC setup and have gains, the argument seems to go towards justifying turbo over SC. Turbo is not free HP, the increased backpressure on the exhuast has an effect as well.
I think the real argument is with efficiency, it seems hard to calculate how much HP is used to run a SC or a turbo, because they both overcome whatever addtional load created and have a positive effect on HP and Torque. When WOT turbos seem to be more efficient, creating more HP with less PSI, but you have to factor in lag and the acceleration differences. Turbos will always have some lag, although greatly improved in the last 30 years.
SC tends to be easier to install, Turbos tend to be a little cheaper. It's just like any other mod, what are you trying to accomplish and how much money have you got?