The total number of cars NASCAR tested on the chassis dyno came to an even dozen according to the NASCAR dyno sheet. The numbers, which are highly suspect due to the wide variance, cover a range that spans 384 – 360 horsepower. Topping the charts was Jack Spragues #60 Pontiac, which carried a Hendrick motor. At the bottom of the list was Ray Evernhams #9, which measured 24 horses short of the best. Falling between the two were engines from the following cars: Tony Stewart, Dave Blaney, Dale Earnhardt Jr., Dale Jarrett, Sterling Marlin, Todd Bodine, Rusty Wallace, Kirk Shelmerdine (in Junie Donlaveys Ford) Jeff Green and Ricky Rudd. Calling the numbers into questioning by many was the Rudds Motorcraft Ford performance, which performed well beyond what the dyno sheets indicated woud occur. However, the chassis dyno is not really the ultimate tool for measuring a cars horsepower levels. So many external influences can affect the readings. Parasitic drag in the drivel line can vary by a great deal with temperature as well real wheel traction to the dyno drums with ambient air and relative humidity changes. While the chassis dyno does give NASCAR a hint of whats going on, in the most general of terms, true comparisons could only take place in a fixed dyno cell where all environmental and operating conditions can be tracked.( Ford Racing )(2-16-2003)
