Siping is a difficult, time-consuming...
Siping is a difficult, time-consuming job. One of the best tools to make the tire specialist's life a little easier is Speedway Motors' new Mega Siper. It uses up to 14 equally spaced razor blades to make several siping cuts at a time, and the depth is also adjustable. The design of the tool reduces the strain on your arms when siping tires for several hours straight.
Chunking is also a problem for the rear tires when the they are under acceleration and the car has a lot of forward bite. Because of this, you may need to grind the rear tires twice-once laterally to prevent the tread from chunking under side-loading, and again around the circumference of the tire to smooth the leading edge of the treads so that they won't chunk under acceleration.
Finally, if you reuse race tires, you may notice that the leading edge of the tread will wear more than the trailing edge. Reusing a tire in this condition will actually reduce the surface area of the contact patch, or the portion of the tire actually contacting the track surface. Wright says that with careful use of the grinder, you can smooth out undulations in a tire to return it to like-new status.
Wright warns that you have to avoid grinding grooves or low spots into the tire that can harm traction. Different tire specialists prefer different tools, but Wright uses a powered sander with a variable speed control and replaceable pads. He says softer tires require slower sander speeds to keep the tire (and pad) from gumming up. For more purposes, he uses sanding pads that have between No. 36 and No. 40 grit.
Finally, when preparing a set of tires for a night of racing, be prepared to spend some time. Wright says properly preparing a new tire (grooving, siping, and sanding) can require as much as two hours. That means eight hours, or a complete work day, for a set of four tires. "It can be a pain when it takes all day to get a set of tires ready," he says, "but you've got to be willing to do what it takes if you want to be fast." CT
Your tire choice is critical for traction on dirt, but the way you prepare them is just as important. Dennis "Rambo" Franklin drives the Barry Wright Race Cars house car and is the defending Southern All-Stars Dirt Late Model touring series champion. Tire specialist Lance Wright shared with us some of his tricks.
Wright grinds another tire. He always grinds in the same direction that a tire will see on the track. In other words, right-side tires are always ground from the outside sidewall to the inside, while left-side tires are ground from the inside sidewall to the outside. This softens the leading edges in the grooves so that they are less likely to chunk on the racetrack.