Reading a dyno graph is comprised of several key elements. Horsepower numbers can be deceiving if not evaluated properly. The following are the basic rules of reading a dyno graph.

Before you can even begin to evaluate a dyno graph, the type of power required must be established. In our case, we are looking for a very wide power curve with emphasis on the horsepower that will be achieved at corner exit. Straightaway performance is dependant upon good corner exit horsepower.

Generally, in micro sprint racing, the RPM at which the car exits the corner is approximately 3,000-4,000 RPM below the rev limit. Of course, this depends on the track layout. When looking at a dyno graph, this number is one of the most important in determining actual on-track performance.

Peak horspower and torque numbers can be very misleading. For example, an engine setup with a lot of cam overlap or short intake runner stacks can make incredible peak horsepower numbers, but these numbers generally only occur in the high RPM range, near the rev limit, and are essentially useless in oval track racing. High peak numbers are generally attained by sacrificing mid-range power. Mid range power is very important in circle track racing for corner exit and total performance.

In short, it's necessary to evaluate the entire horsepower curve rather than just peak numbers. Your dyno tuning facility should be able to aid you in this process. For any additional inquiries on interpreting dyno graphs, please contact Guhl Motors at 717-625-1411.