The durometer is used to measure...
The durometer is used to measure the hardness of rubber products. In the case of racing we use it to measure the hardness of tires. It’s pretty simple: The softer tires tend to develop more grip; and new tires are softer than old tires. But you need to balance wear and grip. The trick is to measure your tires and know when they’re too hard to give you good performance.
So what should the weekend warrior use to gather and analyze data? You may be spared the cost of any computer-based DA system because many local tracks and sanctioning bodies disallow the use of any computer data logging systems on your car on race days so you may be forced to go old-school. But that doesn’t preclude you from using all the tools at your disposal and still fit within the letter and intent of the rules.
As I spend a good bit of time at racetracks around the country I have the opportunity to speak to many racers, asking what parameters on the car they would like to measure. The answers were more common than different, which I found interesting. The majority of our racers were concerned with a minimal number of factors, rpm, speed through corners, braking performance, speed in mph, and acceleration rates. There was also a good sized group of racers who were interested in engine parameters. Every parameter that each racer wanted to measure was a real possibility.
When it came time to decide if they were willing to pay for the opportunity to measure all of the parameters they were interested in, their tune changed a bit. If cost was a driving factor, the variables they wanted to measure went down considerably. The list shortened to speed, rpm, lap times, g-forces, and possibly two pressures—one for brakes and oil pressure or possibly fuel pressure. When the questions were framed with a cost per parameter the number of parameters that were important was reduced significantly. Bottom line, many of the variety of measurable parameters are interesting but when cost was a factor the parameters that they wanted to measure were speed, acceleration rates, rpm, and lap times.
Checking and setting air pressure....
Checking and setting air pressure. What seems like a simple process is in fact frought with issues. The idea is to utilize a process that is performed the same by everybody on the team who may be called on to adjust and set tire pressure. You want to minimize variations in tire pressure caused by improper use of the tool used to measure air pressure.
So where do you start on your foray into building a better DA system for your racing program? The most obvious answer is a couple of stopwatches, some pens, and a spiral notebook are a great place to start. All of this can be purchased for less than $20 at the local Walmart.
Next, a tire temperature gauge is a tool that no race team should be without. We’ll not go into great detail about tire management; we’ve covered that in previous articles. The use of a tire temperature gauge is a tool that will help you monitor how hot your tires get and what the range of temperatures are across the tread surface. Today you can purchase an infrared thermometer for less than $25. I purchased mine for $23.99 at Harbor Freight, and it came with batteries; that’s just too cheap to not have one in your toolbox.
A durometer should be your next tool purchased as part of your DA system. A durometer is used to test the hardness of rubber. It’s a fairly simple equation, for your tires to work and grip the track they have to reach operating temperature. And the more heat cycles, the harder the rubber on your tires will get and the longer it will take them to get up to temperature. What happens is that the volatile light chemicals in the tire will out gas as the tire reaches temperature and the tire will get harder. The tires will not get as soft when they get hot so even when you get old tires up to temperature they won’t grip as well as a tire that has gone through a lesser number of heat cycles. A good durometer will cost in the range of $50 to $60. One can be purchased at almost any racing vendor or speed shop.
If you’re racing, you most certainly already have a tire-pressure gauge. It ranges in price from $50 to as much as $500 for the really fancy digital units. It’s your decision. Look at what your competition uses to get an idea of what your minimum requirement might be.
So, from an equipment perspective you could get by with spending less than $100 and get yourself all set up to have your own analog data acquisition system.