Quote:
Originally Posted by VADER SS L99
I don't see how that is possible and if it were we would be seeing alot more gains from our mods once we reach that magic point. My car stock is in the 320RWHP range and right now its at the 440RWHP range. At what point do my mods equate to 100%RWHP gains? I think the answer should be never. I don't know the exact drivetrain loss for my car but do believe its around 20% both modded and stock. Some cars just have a more efficient drivetrain so their losses are not as great. I am pretty sure almost any Mustang with a heavy 2 piece driveshaft that switches to a 1 piece carbon fiber driveshaft is going to see a increase in RWHP on the same car same dyno. I don't care if he is making 300RWHP or 1000RWHP. Gearing, wheel/tire weight, trans and rear axle type will also play a huge role on how efficient drivetrain losses will be. I don't know if the percentage in losses will go down or not as HP goes up ( maybe someone with a engineering degree can explain why or why not) but I know for sure that you can't get to x amount of horsepower and after that there is no more % lost.
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Lets take your car for a second. It started at 320 rwhp from a stock 400 bhp L99. If you do the math that is about a 20% loss. So to look at it another way, between the engine and the wheels, your drivetrain requires roughly 80 hp of work to spin the transmission, driveshaft, differential, axles, wheels etc. and this also includes losses due to friction.
So now you make 440 rwhp, and using 20% as a factor you might claim to make 550 bhp at the engine now with your mods. But that would mean your drivetrain (which is exactly the same as before) now suddenly requires 110 hp to do the same work it did before to spin the exact same drivetrain. That would imply your drivetrain actually became more inefficient even though the percentage of loss didn't change.
Similarly if you took a stock Mustang and put in a one-piece aluminum driveshaft over the two-piece, you would see some improvement in rwhp, but the engine is still untouched and is not suddenly stronger than before. But someone trying to back calculate engine hp based on a new rwhp number might think the engine is more powerful or underrated.