You Need to Hook it Up! Part Two

We have all tried to go fast without decent tires at the track. Everyone has seen the “drag racer” with the EK Civic powered by a built B20 trying to get the power to the ground through a four-puck race clutch, Type R gears with no LSD and 17 inch Volk TE37 wheels. The pricey wheels are wrapped with a set of 215/40/17 Champro tires bought for $30 at Cooters Discount Alignment and Rubber and he or she can’t figure out why the car spins the tires through fourth gear no matter how much smoke they make in the burnout box. Hmm…

First of all, the tire is the most important thing there is when it comes to putting power to the ground. Who hasn’t seen a tire commercial going on and on like a broken record about the four little patches which separate you from the road? Anyone who knows anything about cars will tell you tires are critical to traction just like feet are critical to walking.

Both Pereda and Moulton recommend changing to a wheel and tire combination that gives you as much sidewall as possible. “The sidewall of the tire absorbs power when you launch the car aggressively,” says Pereda. “This goes for a dedicated drag tire or just a regular street tire.” The bigger sidewalls on a higher profile tire act as a cushion and soften the shock to the contact patch of the tire helping to prevent wheel spin. The larger the sidewall, the more cushion area there is to absorb shock allowing a harder launch or more power to be applied.

This is especially true when it comes to a dedicated drag tire like the BF Goodrich Drag Radial or the Mickey Thompson Sportsman because their sidewalls are designed to absorb the energy which causes wheel spin by being softer so they wrinkle at lower air pressures, making them stretch like a rubber band. “The smaller the wheel the more sidewall you can run and the more elastic the tire is going to be when launched,” says Moulton. “But you can only go so small with a wheel and so big with the sidewall before changing how tall the tire is and messing with the gearing or running into fitment or stability issues,” says Moulton. So how do we know what tire size and type to run?

Because the bias ply tire is so much more pliable high horsepower cars like to run them because they tend to expand and grow taller at high speeds, allowing the car to run more mph at the end of the track. They also tend to wrinkle much easier at lower pressures than radials do without deformation of the contact patch. The downside is because of how pliable they are they tend to walk more meaning the car will dance side to side while driving because the sidewalls are not stiff enough to prevent the car from moving around. This can be a bit unsettling at over 100 miles per hour in a FWD car considering these are the wheels you steer with. One person told me the best thing to do is just hang on and hold the wheel straight. Radials, because of their sturdier construction are much more street friendly which comes into play if you don’t have the bankroll to buy a wheel/tire combo solely for the track.

Running a radial like the BFGoodrich Drag Radial on the street would feel no different than having a typical radial tire on your car. When you get to the track the difference can be felt with almost slick-like traction out of the hole. Theory would tell you the radial construction of the BFGoodrich tire would put it at a disadvantage on the starting line against a bias ply tire, but it’s not completely true. Paul Efantis would pull the front tires off the ground regularly when he was driving his Toyota Supra in 2003.

“Progressiveness is one of the keys to the success of the BFGoodrich Drag Radial,” says Pereda. “A tire has to break loose progressively or you’re not going to be able to control it.” BFGoodrich developed a special compound for their FWD Drag Radial which made the tire extra controllable after breaking loose and realized it would work well on both front and rear-wheel-drive tires and improved the entire Drag Radial line. “Our tires are very gentle when they let go, easy to control,” says Pereda.

“The tire size is related to the goal of the racer,” says Moulton. “If you are bracket
racing, use the tallest, widest tire you can fit for consistency and if you are
heads-up racing, use the smallest tire that will get the job done.” So we need to look at how often the car is raced, and what kind of racing our little friend does. Remember this is just an example. You can apply it to whatever you drive, just change the variables to suit your needs.