Rolling road dyno test.

A rolling road dyno test is a way of testing the power output of a car. The car is driven onto rollers where it is strapped down. A large fan is placed in front of the car to cool the engine. The rollers are weighted down to simulate normal road conditions. The rolling road operator then uses a gear something like 3rd and starts off with low revs almost to the point of stalling, he then accelerates full until the engine reaches its red line.

The car made 276.5BHP on the rollers, but due to slipping on the rollers it caused a slight power loss at high revs. However using the complicated equipment they were able to calculate a true power output of 281 BHP AT 6500 RPM'S and 292 lbft of torque, not bad for 18 PSI of boost!. The slipping is shown on the graph, (bottom linear line) at high rpm you can see where the wheels slipped (line drops rapidly).