[Norm Peterson]

Originally Posted by The Razor

Thanks Norm.

I can assume from your equation, then, the larger tire radius, the lower performance in the 1/4.

Maybe. Tire radius also affects shift points and a couple of other things that I didn't put in the simplified equation above. Basically you'd need to run that calculation for small speed steps where torque and gearing vary accordingly. First gear is likely traction-limited for some or all engine speeds, so you need to keep that upper limit in mind.


ABQ - try this.

[Acceleration (g)] = [Torque (ft-lb)] x [Tranny Gearing (dimensionless)] x [Axle Gearing (dimensionless)] ÷ { [Tire Radius (ft)] x [Car Weight (lb)] }

One g acceleration is approximately 21.9 mph per second.


lundefinedl - it's better if you can model the torque curve rather than use an overall average, as you can then work out incremental accelerations for each mph (or finer, if you're a glutton for spreadsheet punishment). An average taken over a much larger range of speed or engine rpm will give you a general idea what's happening over that range of speeds but won't give you an acceleration curve that reflects the actual engine output.


Norm