bbrown

I've been thinking about all the (cheap) ways to measure horsepower and found that the new GTECH Comp model measure continuous horsepower and torque. Does anyone have any experience with it?

This is all I've found and it doesn't seem favorable:

http://www.timskelton.com/lightning/powertrain/gtech.htm

S4Tune

Because all it does is take the weight of your car, then measures the G forces during acceleration and calculates how much force it would require to accellerate that weight like that. Now that again is relative, because it totally depends on your gearing. And THEN you have another variable with RPMs. HP is torque x RPMs, so without the gtech knowing how fast your engine is going, it has to guess again at the HP. Personally I would say this thing is less useful for measuring absolute values, and much better at relative values. Like, if you get X for max torque, then put a chip in your car and get Y for torque, you know you got Z% increase in power. Then it's easy to calculate your REAL power by matching X with published numbers, and multiplying it by Z. I hope my ghetto math makes some sense and helps a bit

bbrown

in fact this is exactly what I was thinking. they measure RPM by counting alternator spikes in your cigarette adaptor which is the best you can do when you don't have that proprietary interface to the ECU. I figured it was using accelerometers since the cigarette adapter is the only external connection.

I guess its fine if you're not seriously trying to measure horsepower, a cool toy nonetheless.