Tires at Darlington Always a Story

This weekend the famed Southern 500 tag returns to South Carolina’s Darlington Raceway. The track has nicknames like “The Lady in Black” and “The Track too Tough to Tame.” When the 500 was held annually over Labor Day weekend the race earned the moniker “The Granddaddy of Them All.” Throughout the evolution of name changes and date swapping, a constant that always stayed with the race teams at this track was a concern for tires.

The egg-shaped speedway’s surface has a reputation for eating tires. Prior to 2008, the asphalt surface had a mix of stone and sand in the compound that really ate away at the tire’s contact patch. This was a result of the racetrack’s geographical region.

Along with the natural southern red clay, the sand and weather in the area formed the Darlington surface that became so legendary. Rockingham Speedway in North Carolina and Five Flags Speedway in Pensacola, Florida are among tracks that have similar properties. Their locations just form a naturally abrasive surface.

In my opinion this makes for some quality racing. Drivers need to pay attention to tire conservation by running as hard as they can without burning the tires off too soon into a run. The chassis has to be closer to a neutral balance to prevent any extra tire wear that may occur. Pit crews will change four tires often. These extra factors add dimensions to what could already be a dramatic race.

Of course car owners paying the bills are not very excited about the effect all the tire changes have on the team budget.

Last year’s Mother’s Day weekend contest was held under different circumstances than described above. The 1.366-mile course was repaved before the NASCAR machines moved in and brought a new team viewpoint.

The new pavement was not “cheese grading” tires, as one crew member put it to me. Tires were actually lasting and showing wear consistent with other speedways.

One year ago I was employed by a Nationwide Series team and working at the 200-mile Friday night race. Fortunately for our story, my duties were one of a tire specialist.

A general rule of thumb for tires and paved track surfaces is this: old pavement and new tires go together; new pavement and old tires go together. A worn out asphalt track wears tires so much, that one needs new tires at every opportunity. New asphalt provides better grip for a tire that is a little harder.

New tires are hardened up by heat cycles. Race teams refer to this process as scuffing. A car will head out for a few laps in practice return to the garage, and four tires will be changed. The car again will turn a few laps and the work is repeated.

The heating of the tires by making laps and then removing them and setting the set off to the side to cool will make a more desirable compound for new asphalt. In 2009, we were doing something pretty rare, scuffing tires at Darlington Raceway.

Another crew member friend joked to me “we used to scuff tires by rolling the car through tech line.”

During the 147-lap Nationwide event the unusually lasting tires allowed us to incorporate some track position and fuel strategy in our race game plan. This differed from the common “put four on every chance” routine.

Nationwide teams do have to manage tires differently than the Sprint Cup cousins. Six sets are allowed for use during a race weekend. That includes practice and qualifying. It helps save the second tier teams money and a crew chief needs to keep this in mind when making chassis changes and pit stop calls. This brings another added element that increases race intrigue.

Now the 2009 event draws near. A year of weather has passed over the legendary speedway. It remains to be seen what kind of racing we will get out of the year-old surface. Will tremendous tire wear return? Or will they last and some pit road calls be put into play?

Tire tests have been conducted so we hope for great tire compounds and construction that balance safety and competition.

There are many aspects with just tires that come up at Darlington and we haven’t even discussed about any nuts or bolts on the race cars themselves. This could make for a very interesting Southern 500.