R6 Care Sheet

1st phase: The initial run
2nd phase: The length of the time the tire is allowed to "cure"

The first laps for the tire are critical for setting up the durability and competitive life. The 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. The 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 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.

For autocrossing, the A6 does not need the same break in procedure as the R6. The A6 needs a minimal scuff-in session before the first autocross run. This “session” can comprise of simply driving around the event site at minimal speeds on the A6 set of tires. By scrubbing off the newness of the tread (no or minimal shininess remaining) prior to your first competitive run, the A6 tires will be more consistent in handling, grip and responsiveness on the first run. If this is not completed, running on un-scuffed A6 tires on your first run may result in the tires not gripping properly, or feeling like they “skate” over the course surface. You are welcome to run 3 – 5 psi higher when scuffing in a new set of A6’s, but be sure to reset them to the correct operating pressures before your first autocross run. As you compile autocross runs on your new A6’s, they should become more consistent in run times.

"Cure" Time
After completing the initial run phase, the length of time the tire is allowed to set is possibly more important. The barest minimum for this process to be beneficial is 24 hours. (Not "the next day"). Any less than this is a waste of time. The best situation would allow a week before using the tire again.

Proper tire management is a difficult process. To accomplish this almost always requires a second set of wheels. The payoff is greatly increased competitive tire life.

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 for the R6 in Roadrace applications, and 140-150 degrees for the A6 in an Autocross application.

The Hoosier tires typically offer better performance with spring/shock rates higher than previous brands you may have run.

Traditionally, Hoosier tires have often required higher pressures than other brands. This has changed with the A6/R6.

+Higher pressures will improve the performance capability but will require a more sensitive feel to take advantage of the increase.

One characteristic of the tires is the tendency to "skate" 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.

For autocross applications, your starting pressure for the first run should be within 1-2 psi of the recommended hot pressures shown above. After the first run and each subsequent run, keep resetting the pressures back to your target hot pressures before taking the next run. This way your tires are at the proper pressure during the bulk of every run you take.

The above chart is a general recommendation which is intended for a standard configuration vehicle (i.e. front engine, rear wheel drive). Factors which can radically affect your pressure set up would include front wheel drive, independent rear suspension, rear engine, McPherson vs. control arm front suspension.

Front Wheel Drive
Vehicles configured with FWD are probably the most difficult application for a tire setup. The combination of steering, braking and accelerating on the front tires, combined with higher corner weights for the front positions produce a harsh environment for the tire. These vehicles will typically have a strut type of suspension which limits camber gain. All these factors result in conditions which require the tire do more work than a simple chart for pressures can accommodate.

In severe cases front tire pressures for FWD vehicles can run in the 48-52 psi (hot). In cases where the tire size is limited to a relatively small tire, the required pressure can run even higher. The front to rear pressure differential on FWD cars can have extreme ranges of inflation, depending on the driver preference, suspension tuning, and track configuration.

Independent rear suspension
With IRS and proper geometry up front, tire pressures can be reduced from the recommendations listed above. When there is adequate camber gain and good roll control, the Hoosier radial tire will perform very well at the reduced air pressure. This results in a bigger "sweet spot" and easier control at the limit.

When tuning at reduced pressures use the following formula to determine the minimum safe pressure: Divide the total vehicle weight, including fuel and driver, by 100 to arrive at the minimum safe pressure. Example: Your car weighs 2750 lbs. as raced. The minimum safe (cold) pressure is 27.5 psi.

Extreme care should be taken when tuning at reduced pressure. Tire damage can occur that is not visible to external inspection.

THINGS TO CONSIDER
These tires are molded to their designed tread depth. They do not require shaving to be prepared for competition use.

Due to extremely light construction, Hoosier tires have a much lower polar moment than other radial tires. This translates to a very low rotational mass, which is a good thing for performance applications. The down side to this feature is that the tires do not resist "spikes" in braking force as well as a heavier tire might. As a result, there is a tendency for drivers to "flatspot" a tire the first time really getting to the limit. Vehicles equipped with ABS will benefit from its use. If you do not use ABS it is recommended that you make an effort to minimize stabbing the brakes until you have some experience with the feel of the tire under hard braking.

The light construction also provides less protection from impact damage and punctures. Off course excursions or running over debris on the track will likely result in tire damage.

The tires are not directional. Once some wear has occurred it may be desirable to flip the tire on the wheel in order to even out the wear and maximize tire life.

Wheel Widths
Wheel width dramatically affects wear and performance of the Hoosier P-Metric radial tires.

There is about a one inch window of optimum width. The trick is to figure out that window. A good rule of thumb to use for determining proper width is to use the tread width of the tire. Measure the tread width. Plus or minus 1/2 inch from the tread dimension will indicate the proper rim sizing. It is possible to use narrower wheels, but at a sacrifice to shoulder wear and cornering power.

"Measured" rim vs. "Recommended" rim
In our printed product catalog and on our website tire specifications you will see two columns of information regarding rim dimensions. In most cases, the "measured rim" and the "recommended rim" will be the same. However in the case of DOT tires, the information may appear contradictory.

The reason for the differences lies in the Department of Transportation requirements for publishing tire dimensions on any tire that carries a DOT certification. Each tire size has a specific rim that must be used when taking measurements for tire comparison. This is intended to allow consumers a consistent way to compare tire sizes between brands.

With respect to the Hoosier P-Metric line, the recommended rim size will typically be wider than the DOT standardized wheel.

The fact that a tire will "fit" on a rim is not an indication that it will work effectively in that condition. Radial tires are extremely sensitive to wheel widths. The performance characteristics of the tire can change significantly within the recommended range of application. Mounting a tire on a rim that is outside of the recommendation is not a good idea.

Driving Style/Braking
Driving style has also shown to significantly effect tire wear. Drivers who achieve their speed by "tossing" the car run the risk of increased tire wear. Radial tires develop their highest cornering power at relatively low slip angles. Smooth, tidy driving yields faster lap times and better tire wear.

The braking feel of the Hoosier R6 tire is very vague at the threshold. This is particularly true for "sticker" tires. Drivers need to develop a sensitivity for the limits under braking. This takes time and practice. Failure to apply this will result in flatspotted tires.

Particular care needs to be taken when selecting brake pad compounds. It is possible to have a pad that is too aggressive. This will make it very difficult to develop good braking fell for threshold braking.

Rain Tires
The Hoosier D.O.T. Radial tires are extremely good in dry conditions, however they do not make very good wet weather tires. Having dedicated rain tires available will be necessary for your team to be properly prepared. Hoosier makes a D.O.T. approved bias-ply tire called a "Dirt Stocker" that has been proven to be far superior to any competitors tire as long as it is a steady "wet" condition. Check with your Hoosier representative for size availability.

Hoosier Racing Tire also offers a D.O.T. Radial Wet tire. This tire has a molded tread of symmetrical design. Check the product catalog for the available sizes. The compound for these tires is intended for wet weather use only.

Hoosier also offers a non-D.O.T. radial rain tire based directly on the P-Metric R6 tire. The tread depth is 8/32" and the pattern is the same tread design found on the R6. They have been allowed in BMW Club racing and many other sports car clubs as well. Mounting instructions can be found in the “Road Racing FAQ” section of the website. The list of available sizes can be found in the "road racing/tire specs” section of our website.

When using rain tires, always increase your starting air pressure 2-4 psi over your dry tire pressures.