The equations do take into account aerodynamic drag but not drivetrain or tire rolling resistance. I tried calculating just the aerodynamic drag part but I came up with a ridiculously low number, like 1 lbf, which doesn't make any sense at all. I'm using the frontal area and drag coefficient from a 3g Prelude so that should be pretty close. One of these days I would like to do a coast down test to get an idea of actual tire, drivetrain, and aero-drag losses, but I haven't found a long enough stretch of flat road yet where I won't hold up traffic.

As far as the 15% goes, I don't see how a (manual) FWD car is going to have any more loss than that. Even 15HP of loss would be a tremendous amount of heat to dissipate, which is of course where nearly all of the lost energy goes. For a RWD slushbox, yeah I could see 15% or more. For a FWD manual, no.

2200lbs may be a little light. I was basing that on the fact that I lost enough weight in the front to have to do the pinch fork mod just to get back down to stock ride height. I did try bumping up the weight a little but it didn't make more than maybe 3HP difference.

So about 1/4 mile times. Do you have a formula for calculating HP based on 1/4 mile times and weight? I could work out the physics but if you have a faster rule of thumb calc it would save me some work.

The graph is a little funky I think because the speed signal has some noise in it. I need to see if I can filter it to smooth things out.

Oh, and top speed shouldn't matter. At WOT the engine will put out max torque (for the RPMs at that instant) and will accelerate faster or slower based on the load present. The engine doesn't have any idea how fast the car is traveling. I want to try some 3rd gear pulls but have to watch for law enforcement representatives.

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