Garlits Talks Tire Shake

With Prudhomme, Austin Coil, Mongoo$e and more

- Sam Logan

“IN MY HEYDAY, TO DELIVER THE PERFECT DRAG RACING RUN WE RACED A VERY FINE LINE,” ASSERTS DON GARLITS. “If you had the exact right size tire for the weight of the vehicle, and the clutch set exactly right for the horsepower of the vehicle, and a track surface compatible with the combination, you could make a perfect run. But if the tire was too big it would shake. If the tire was too small it would spin. If the clutch was set too tight, it could shake. If the clutch was set too loose, it would over-rev the engine. If engine power was excessive it would spin the tires. If engine power was insufficient it would shake the tires. If the vehicle was too light it would spin the tires. If it was too heavy it would shake the tires.”

What would happen if there was a little more wheel speed than ground speed?

“A tiny bit of tire spin used to be okay. In my day, we had access to 3,500 to 4,000 horsepower, but today, if you go out and spin the tires, you lose the race. Back then it was okay to see a little puff of blue at about 300 or 400 feet because you knew the clutch had locked up and that little bit of blue told you the tires had caught up with you, and you were now one to one. On this formula, the 392 engine worked the best. When we saw it pop a little blue out there at 400 or 500 feet that son-of-a-gun was on song!”

Where was the effect of tire shake most prominent?

“The shake took place just off the starting line. The car might have been trying to get up on the tire, but didn’t have enough power to do it because the tire was too big for the prevailing horsepower, and the clutch was a little too aggressive. Had the clutch been a little bit looser, or if a little more horsepower were available, or had we used a little smaller tire, it wouldn’t have shook. Today, with computer aided data, it seems closer to becoming an exact science.”