chassis dyno

[art leong]

Originally Posted by Run to Rund

I have personally done over 1000 runs on a Dynojet ( up to 800 HP at the wheels) and learned about them from a man who did some of the development with Dynojet and has about a half million runs under his belt. Mike gave some good info. The single roller type, big diameter roller are best especially for slicks. the double roller type are very hard on any tire. Dynojets with the 48" diameter drum are available with different units (slugs) of intertia. Perhaps the most common simulates a 4500 lb. vehicle. I have found NO difference from tire diameter or rear gearing. HP is defined as the rate of doing work and is therefore measured directly by an inertia dyno. You change (multiply) torque with gears, etc. but not HP. Once being sure to keep engine temp, fuel temp, etc. under control, I have found the Dynojet reproducible within about 2 HP run after run.

I was on a Dynojet the Wednesday before Commerce, And it was set up for a 3500 pound car. They told me the number would be wrong but you could still see a help or hurt situation. I didn't understand what they meant I thought it was just reseting some of the hardware. But now I see why they didn't recalibrate the dyno.
I made 217 whp, on there with it set up for 3500 pounds and I was 2500 Any idea of what I was really making?