I got a G-tech competition pro off ebay for $138 and have been messing around with it .
I think I am doing something wrong though Its says my max hp is around 170 .

I'm sure I should have much more than that, stock is 187 rwhp.
and I have all kinds of mods.
5.2
ss headers , High flow cat ,flowmaster 40
cold air intake, fastman tb, excel coil, 180* tstat , electric radiator fan, under-drive pulleys,

You would think it should read about 200 rwhp.

 

Those things are notoriously innacurate....especially when it comes to estimating quarter mile time. [:'(]

I know several people in the Grand Prix community that have tried them, and they've never been accurate.

I'm not even sure how it could begin to estimate rwhp [&:] The only way to do that is to put your truck on a dynometer.

 

I always wondered that too....how can you plug something into your cig. lighter and it somehow tells you rwhp? Its probably something REALLY stupid like you tell it what car you have and it knows how much it weights. Then when you floor it it like measures the g-force (which isn't much ) and ghetto calculates it. I wouldn't be supprosed if it worked like that...[sm=dontgetit.gif][sm=bs.gif]

 

Car Craft did a test on one of those last year. It was accurate within about .1 in the quarter mile and 2 or 3 MPH. Not bad for a cheap device.

And if you know quarter mile MPH, vehicle weight and gear ratio you CAN determine RWHP fairly accurately.

 

The Hypertech PowerPAC is said to do that same thing, but that is pluged into the OBDII diagnostic port and moniters it constant, and real time. Wondering if it is more acurate that the G-Tech.