Quote:
Originally Posted by Kevin M
Well, true- but that airflow isn't actually a force applied against the acceleration against the car.
The way dynos account for the missing air resistance is through simple physics. If you know the drag coefficient of the car reasonably closely (and dyno software comes with presets for nearly every commonly tuned car) it's just a matter of subtracting the function of air resistance vs. speed for that car from the power read by the rollers. Road tuning, on the other hand, has no way to account for varying winds, varying slopes in the road, and therefore have a higher margin of error than shop dynos.
|
All a dyno has to do is provide repeatable load on the motor as it pulls through the power band for tuning. Good airflow is just for proper cooling.
All that other mumbo-jumbo about cd and drag computation is to generate some horsepower number to brag about and has no real bearing on the tuning of the car.