All Hoosier Tires are designed only for competition purposes. Proper break-in will not affect initial performance but will increase the competitive life of the tire.
Hoosier Tires including DOT labeled Hoosier Racing Tires are designed for competition purposes only on specified racing surfaces and they can’t be used on public roadways.
Introduction to Hoosier Tires models
Hoosier Tire Sports Car DOT A7 Radials
Hoosier Tire Sports Car DOT A7 Radials are Racetrack & Autocross Only tires developed for drivers who compete in autocross, time trial and hillclimb events in dry conditions where responsiveness and high levels of grip at lower operating temperatures are desirable. A7 Radials are also used for road racing on lightweight cars or when competing in cool ambient temperatures where Hoosier Sports Car DOT R6 Radials cannot be brought up to favorable operating temperatures.
Hoosier Tire Sports Car DOT Radial R7
Hoosier Tire Sports Car DOT Radial R7 tires are Racetrack & Autocross Only tires developed for drivers who compete in road racing where responsiveness and high levels of grip in hot, dry conditions are desirable. Radial R7 tires are designed to reward drivers with fast, consistent lap times and extended wear due to their traction and handling.
Tire Break-in procedure
Proper break-in will not affect initial performance but will increase the competitive life of the Hoosier tires.
To scuff a set of tires, start by taking one or two moderately paced laps to gradually bring the tires up to operating temperature, and then run one hard lap followed by a cool down lap. The ideal situation would be to stop and remove the tires from the car and allow them to cool down to ambient temperature before running them again. When running an entire session on a new set of tires without stopping, one should still follow the scuffing procedure at the beginning of the session before turning laps at a fast pace. It’s also very important to run a slower lap at some point in the middle of the session to allow the tires to cool off before running hard laps again.
Initial Run Heat Cycle | A7 R7 Roadrace
The first laps for the tire are critical for setting up the durability and competitive life. First session should consist of no more than 10-15 minutes of running. The early part of the session should be run at an easy pace, with the speed gradually increased until the end of the session. Final lap should be run at the fastest possible speed. The intent is to achieve maximum tire temp on the last lap. At this point the car should be brought in and the tires allowed to cool at a normal rate.
During the initial run-in process, the inflation pressure should be 3-5 psi (0,2 – 0,4 Bar ) higher than you would normally use. The best progression would have the driver taking 4-7 laps to accomplish this break-in. Each lap should be approximately 7-10 seconds a lap faster than the previous lap. The goal is to have the tire temp as high as possible on the last lap without “shocking” the tire during the warm up laps. In essence, no wheelspin, late braking, or sliding. The last lap should be at, or very close, the maximum possible.
Tire Temperature Recommendations
For best performance the expected temperature range will vary from track to track. Generally, optimum traction will be generated when the pit lane temps show 180-200 degrees F ( 80°C – 95°C ) for the R7 in Roadrace applications, and 110-140 degrees F (45°C – 60°C ) for the A7 in an Autocross application.
To get accurate hot tire temperatures, you should use a tire prometer with needle probe.
With the Tire gauge HPM4 with a built in pyrometer you can measure and save the tire temperatures of the tread and also tire pressures.
It is possible to evaluate the dynamic setup of the vehicle through the evaluation of the temperatures in the different points of the tread.
Air Pressures recommendations for the Hoosier tires
One characteristic of new tires is the feeling of lower traction initially (when inflation pressures are correct). It is important to resist lowering the pressure to attempt to eliminate this feeling. Dropping the pressure too far may improve the “feel” of the tire however it will also lower the performance and increase the wear rate.
Never drop hot tire pressures back down to cold pressure set points. Tires will be severely under inflated as a result of dropping hot pressures to cold pressure set points which will lead to increased tread wear and possible tire separation. Hot pressures will gradually return to the cold starting pressure as the tires cool off.
Measuring the difference from the COLD and HOT tire pressures with the tire gauge HiPreMa 4
For every 10 degrees F ( 5°C ) increase in air temperature, the tire pressure will gain approximately .7 psi ( 0,05 Bar ). As Air Temperatures increase throughout the day, so will the Air Pressures in your tires.
Keep in mind that using compressed air (with moisture) and nitrogen (little to no moisture), will offer quite different air pressure increases. Using Nitrogen will offer more consistent air pressure readings, repeatable tire performance and improved overall results.
Measuring TIRE PRESSURE and TIRE TEMPERATURE with the multifunctions instrument —> more info
Tire care and safety Guidelines: https://www.hoosiertire.com/images/content/files/TCTR7_A7.pdf
Hoosier tires overview : https://www.hoosiertire.com/tires/