It's a bit past mid-season, your racing effort has been fairly successful and you need to have some decent finishes to round out the year. What you don't need are problems that come up and ruin a whole race for you. If you have been racing for any length of time, you will have experienced a problem that comes seemingly out of nowhere and bites you in the tail, usually at the worst possible moment. Most racing jinxes come from lack of maintenance or failure to recognize a potential problem.Use a large-dial air pressure...
Use a large-dial air pressure gauge and record all pressures, both cold and hot. DO NOT EVER use a clamp-on air hose end to fill a race tire, or any tire for that matter. Unattended tires that are being filled this way can and do overinflate to the point of exploding.
1. Tire Preparation
A team has prepared its car exactly the way it needs to, the setup is perfect, the engine has been gone over and tuned to the day's conditions, the crew is on top of all of the many maintenance items. The only thing different is that the usual tire specialist was not able to attend this race and the crew recruits a guy who "knows all about" tires.
He is allowed to select, air up, label, and position the tires for mounting on the car. No one watches over this guy and no one checks up on him to see if he indeed knows what to do.
Everything goes well with the selection and setting the air pressures, the only problem is that he places the tires backwards from the usual procedure and the crew then proceeds to mount up the tires. The left-side tires go on the right side of the car and the right-side tires go on the left side of the car. This results in air pressures and sizes that are reversed. The tires were labeled correctly but the writing is too small to see easily. So, no one catches the mistake until after the race. Needless to say, the car ran like crap.
Plainly label each tire with...
Plainly label each tire with information about which corner it was run on, the date, the set number, and so on. You can avoid mistakes that end up with the tires being put on the wrong corners of the car. Your team should designate one or two permanent crew members to prepare and care for the tires. This job is so important to the success of the team. If you use a new person for some reason, work with him to develop the good habits that are necessary.
Stagger changes can also be a problem. Again, all seems perfectly fine, the driver in practice likes the setup and you are in the top three with your lap times. You bolt on a new set of race tires and go out to compete. Somewhere along about lap 20-40 the car goes tight or loose. Needless to say, you don't finish very well that night.
After the race, you measure the stagger and find out the rear stagger either closed up or grew beyond what works at your track. At some racetracks, we can get away with this better than at others. I worked with a team that won a race and the rear stagger closed up to 3/8 inch from the normal 1 3/4 inch. The driver said he couldn't feel the difference.
At another track, if the stagger changes more than 1/4 inch, the car will not handle. That's tough to deal with. The solution, as much as is possible in this situation, is to get to know the particular tire you race with. Each brand and product number of tire has its own characteristics for growth related to your car and the track you are running on. The choice in new tire sizes must be made by knowing how much the tires on each side of the car will grow.Practice is the time to evaluate the tire growth situation. The tires on both sides will grow due to elevated temperatures and the increased pressures that go along with a hotter tire. The right sides will gain more temperature and pressure than the left sides and therefore the sizes on the right side should grow more. How much is dependent on many factors, some of which are: a) having the correct stagger to begin with, b) having a balanced setup, or not, c) using dry air or nitrogen, d) the structure of the tire as well as the particular production batch, e) and believe it or not, how hard you run the car.