H/P to weight question

[DeuceCoupe]

Originally Posted by pfordamx

i'm curious if this is wheel or flywheel hp too, and my other curiosity is if your mph show significantly less hp than e.t. at the same weight does that just mean you have a efficient car?

It looks like the Wallace link uses NET flywheel power. Then they make assumptions to translate that to rear wheel power which is what move the car. Note they say the formula is just approximate, eg they don't even ask what transmission you have.


If MPH is low it can mean a bunch of stuff
1. Running out of fuel on top (common in my old junk)
2. Running out of revs
3. Brick-like aero or headwind (a 5mph headwind will reduce trap speed about 1mph - varies by car of course)
4. Other


If you have open headers, not too many belt drives, a big air filter, and cold air coming in, NET horsepower will get really close to GROSS horsepower. Still some losses to get to the rear wheels, no way around that.