[bytejunkie]

Originally Posted by Aragorn30d

It has to be proportional to the input.

i dont want to get into a massive debate about that unless you want to create a new thread, in which case, i love a good debate, everyone learns from it.

its not all proportional to the input.

couple of examples.

there is an amount of friction to is to be overcome from a standing start. no bearing is perfect. brakes are usually interference slightly. an amount of power (maybe tiny) is needed to get the car rolling.

then you've got a bunch of things that give a continuous resistance, a CV joint, donut in a drivetrain for instance.

the gearbox and diffs resistance will all change due to temperature, how viscous the liquid gets to be. proportional to the input maybe, but only at the same temperature and torque every time.

so i don't see it being a straight line from 0 to max, but at max speed of the car, or for purposes of a dyno pull, at 6000 revs in fourth, it ought to be similar from a run before a map to a run after a map.

@OP, I'll give them a call over the weekend, thanks.

[Aragorn30d]

i'm not really sure we even disagree...

I'm saying theres various parts some which are related to speed, some related to power, and some which are constant(ish).

Your saying essentially the same thing.

On a dyno pull, the speed and "constant" parts will be the same, assuming the bloke runs the car in the same gear and doesnt cheat by using a different gear for one set of results, and assuming the tyre pressures dont change, and the gearbox temperatures are the same for each run, and the cars strapped down EXACTLY the same, and various other factors. The power part will increase with power.

so it IS proportional, its just not linear, and the error bars are huge. You could easily see MORE losses simply by strapping the car down slightly differently, or running it up on a cold gearbox, than you get from adding 100hp.