[dgc333]

The only thing that is not accurate about the G-Tech is the trap speed that is reported with the 1/4 miles times (at least with the older version). That is because of the way the G-Tech reports it compared to the drag strip. You trap speed at the drag strip is an average of the last 60 feet. The G-Tech reports the speed at the end of the 1/4. The G-Tech will give you a higher speed. The horse power calculations are approximations. It requires you to provide an accurate weight of the car and driver at the time of the run and does not take into effect wind resistance. That is a very aerodynamic car and a barn door weight the same and run identical times. The barn door will require more power to match the aerodynamic car but the G-Tech will report they are the same.

The new ones have tach functions that will require some sort of connection to the engine.