Has anyone used one? The G-TECH/Pro uses an acclerometer, and the Blitz Power Meter looks like it works off the speed sensor. (I'm not sure about the latter.) How well do they work Is one better than the other? Are there other brands out there?

 

^^^

 

last up

 

I've used the g-tech and it is accurate for your Street 1/4 mile time. The track is different, being that you will run better 1/4 mile times at the track, mostly due to traction. G-tech also does 0-60 and braking time, and some more crap i can't think of right now. I don't think it has anything to do with a dyno though, at least the G-tech.

 

Any of these types of "dynos" short of a full data acquisition system will not be accurate.

The Gtech is pretty accurate for ET (0.2sec or so fast), it consistently reads 5-8 mph high. It is not accurate enough on HP or Tq for tuning purposes since its errors are cumulative over the distance of the run and you need to know the exact weight of the car during the run.