Each month, Stock Car Racing asks a set of readers' questions to a different professional in the racing industry. If you have a question, send it to Stock Car Racing, 5555 Concord Pkwy. South, Suite 330, Concord, NC 28027, or via e-mail to stockcar@primediacmmg.com.
Q: What kind of manual transmissions do Winston Cup teams use and who makes them?Kelvin ThomasBaskerville, VA
A: The only transmission legal in the Craftsman Truck, Busch and Winston Cup series is a four-speed, forward-drive transmission. It also has to have a working reverse. Predominantly, everyone uses either Jerico transmissions or Rankin transmissions. There's also another one that is used, a T-101 transmission you get from Tex Racing. Those are the three transmissions I know are being used currently.
Q: What is the biggest difference between a Craftsman Truck engine and a Winston Cup engine?Todd BenfieldSalt Lake City, UT
A: In the current rules, the only difference is that the Truck engines are allowed to run roller cam systems, while the Winston Cup engines run what are called flat tappets in the valve lifters.
Q: How much wind tunnel testing, if any, do most Truck teams do?Jill BeasleyDetroit, MI
A: I would say it depends upon the operation. The 24 and 17 teams have been to the wind tunnel five times this year. Obviously, the more competitive the team, the more it's able to go to the wind tunnel. The manufacturers try to allow their teams to go at least once each season. But there are some specifics and general specifications and results we find out at the wind tunnel and give the OK to the manufacturer representative to pass on to teams that aren't well funded enough to be able to go themselves.
Q: What is a rev limiter and what does it do?William GallahanKing George, VA
A: The rev limiter is an electronic module that hooks into the MSD ignition box, which is similar to a coil or voltage regulator on a standard streetcar. The rev limiter prohibits the motor from turning, under acceleration, past a specific rpm, whatever you have the chip in the box set to allow it to turn to. The way it operates is it electronically shuts down cylinders in the engine. The power is decreased and therefore it can't turn any more rpms. This is used to keep, as the name implies, the engine from being revved at an rpm greater than what its intended use is. A rev limiter, however, does not work on downshifting. So if you're at a road course or a place like St. Louis, where you actually downshift during the race, it will not stop the engine from over-revving under those circumstances. The biggest benefit it gives is when a driver is leaving pit road and going through the gears. It doesn't let the driver, in the heat of competition, over-rev the engine going through the gears. It's almost never that an over-revving situation would take place during a race, simply because that's why you go to a racetrack and practice before a race. That way you'll know what gear ratios to run and be comfortable shifting.
Q: How many body parts on a Craftsman Truck are actually stock?Christine SaslowFort Worth, TX
A: The bed tops are stock, the roof is stock, the hood is stock, the front fender tops are stock and the A posts and B posts are stock. Other than that, everything else is hand fabricated.
Q: How many paint and body men do most Winston Cup teams employ? How many fabricators?Michael SingletonCarlsbad, CA
A: For most of them, I would say a solid number would be three paint and body men. Then they typically have six to eight fabricators.