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[Andy@Ross-Tech.com]

Why would RPM have any effect on the 1/4 mile ET calculation? Their calculation is pretty simple:

Acceleration is measured by the sensor(s) in g's. 1 g = 9.81 m/s^2. They are sampling, say, every 0.1 s. By multiplying the acceleration times the the time slice, you get the speed. By multiplying the speed times the time slice, you get the distance travelled. Add up each of the distances you travelled until you get to 1/4 mile (about 403 meters). For both the ET and trap speed, the only two variables needed are time and acceleration. The vehicle weight, rpm, etc. are only needed for their dubious "horsepower" calculation. The problem with their horsepower calculation is, in their own words:

Quote:

The horsepower that G-Tech measures also includes vehicle aerodynamic drag. This means that if you tape over your headlights and grill, remove rear view mirrors and windshield wipers to reduce your drag, you will measure a Horsepower increase even though you didn't make any changes to the engine. After adding an aftermarket spoiler you will likely find a decrease in measured horsepower, since you increased the drag losses on your vehicle.

This, like their trap speed measurement, isn't comparable to any of the standardized methods of measuring horsepower. What they are failing to do, is measure the power absorbed by the road, air, tires, etc. By leaving this out, they are missing a large component of horsepower. Here's more information on a better and more accurate way to do it:

http://forums.audiworld.com/vag/msgs/457.phtml