Tech Q&A: James Ince

February 5, 2001
6:01 PM EST (2301 GMT)

Q: What are the compression ratio specifications for Winston Cup cars and Busch Series cars? Is there a +/- tolerance given in the NASCAR rulebook? Shaun Schultz Oswego, IL

A: The compression ratio for the Winston Cup cars is a maximum of 12.5:1. It's actually 12:1, but you get a half-pound of tolerance by NASCAR. With the Busch car, the compression ratio is 9:1, with a maximum tolerance of 9.5:1.

Q: How exactly does air pressure effect the handling of a race car? Richard Waldorf, MD

A: Basically, the main issue with air pressure is that it is also spring rate. If we add air pressure to our Goodyear tires, we're adding spring weight. If we take away air pressure, we take away weight, so it directly effects the overall setup of the car. One pound of air pressure equals 25 pounds of spring rate.

Q: How many quarts of oil does a Winston Cup car take and use? Allyson Cole Budd Lake

A: We generally use 16 quarts of oil during a 500-mile race in Winston Cup. The car will usually consume two and a half to three quarts.

Q: Which tires wear the fastest on short tracks? How does increasing or decreasing the tire pressure in the left- or right-side tires help and what does it do in the long run? Colby Knight Las Vegas/Henderson, NV

A: The right-side tires are generally worse, since the G -forces are all put there. That's another place air pressure becomes so important. What we do with air pressure is to help with wear. Really though, the left front could wear worse because car rolls over so much in the corner, where the left front drags the car around.

Q: On every Winston Cup wheel there is a yellow arrow with the letters AER on it. What does this mean? John Clark Phoenix

A: That's actually the logo of the wheel manufacturer. The majority of Winston Cup teams use Aero Wheels.

Q: If drivers are involved in an accident and both cannot return to the track, what determines their ending position on the final results if their position before the crash was the same? Doug Yankee Blue Springs

A: If the two cars crash at same time, the officials usually look at the previous lap and score it accordingly as to where they were at that time.