How To Care For Michelin Pilot Sport Cup Tires

Tire Heat Cycling
Michelin has noted an improvement in tire wear with heat cycled tires and that they may come up to operating temperature slightly quicker than non-heat cycled tires. Additionally, Michelin has also noted a marginal improvement in lap times (maybe .1-.2 sec in a 38-40 sec autocross environment) on some cars. The improvement is not always obvious.

Heat cycling can be performed mechanically at The Tire Rack before the tires are shipped or by driving on them after they have been installed. It is important to remember that the 24 to 48 hour "resting" period for the tire following heat cycling is an important element to the process’ success.

Tire Shaving
Pilot Sport Cup DOT-Legal Competition tires are molded with less tread depth than typical street performance tires. Michelin Pilot Sport (Max Performance category) street tires are molded with about 10/32" of original center tread depth, while Pilot Sport Cup Competition tires are molded with just 6/32" of original center tread depth.

Michelin testing shows that a Michelin Sport Cup shaved tire at approximately 3.5/32" offers slightly more grip at the start of the tire’s competition life. The time differential between shaved/heat cycled tires and full tread depth/heat cycled tires on a typical 38-40 sec autocross course can be as much as 0.6 seconds. And while these are statistically sound results, your results may vary.

Drivers must decide if they are willing to invest the cost of shaving and sacrificing approximately 2.5/32" of tread depth in exchange for a potential 0.6 second improvement. It all depends on how serious you are about your time spent at the track or in competition.

However all things considered, the absolute quickest time will likely be achieved by shaving and heat cycling Pilot Sport Cup tires.

Use of Metal Valve Stems and Metal Valve Caps
Michelin recommends the use of metal valve stems in wheels used for competition, but recognizes that many wheels require additional machining or preparation to accept metal stems. Inspect all valve stems for cracks, signs of aging or other damage whenever changing tires.

The valve in the stem is there for the purpose of inflating the tire, and not as a safety system. In hard use at high temperatures (particularly at high speeds that generate high centrifugal loads on the valve) the valve can weep small amounts of inflation pressure. Enough of these tiny momentary leaks can decrease the tire’s hot operating pressure to a level that can lead to tire damage. The best result from tire damage in a competition setting due to underinflation is that you cannot use the tire anymore. The worst result is obvious.

Regardless of the stem material, (metal or rubber) Michelin recommends a good metal cap that is equipped with a high-temperature gasket. With such a cap providing the primary seal, if the valve fails, the internal pressure of the tire is still contained. Why metal? Michelin engineers have seen plenty of plastic caps melt right off of a stem that has been exposed to serious brake heat.

Tire Installation
Pilot Sport Cup tires feature a non-directional, asymmetric tread design. To facilitate installation, the sidewall adjacent to the shoulder featuring the continuous "rib" design is marked "outer" and should be mounted facing towards the outside of the wheel.

Vehicle Wheel Alignment Recommendations

Camber should be negative:

Acceptable 1 degree negative

Preferred 1.5 to 3 degrees negative (for most basically-stock or moderately-modified cars, the "sweet spot" is going to be in this range)

Maximum 4 degrees negative

Proceed carefully with camber adjustments. Too much camber means giving up efficiency in braking and accelerating. Achieving the right balance between cornering grip and straight-line grip (braking/accelerating) is key. For those enthusiasts who simply want the opportunity to explore their vehicles’ limits with higher levels of grip, but who don’t want to make serious modifications to achieve high negative camber values, Pilot Sport Cup will still operate effectively with more conservative factory settings for camber.

Caster should be set at the vehicle’s most positive recommended setting.

In most cases, toe should be set at the middle of the vehicle’s factory spec for each axle. However, depending on the competition situation (tight road course, more open, flowing road course, autocross, etc.) it is possible to materially affect the initial turn-in of the car and its stability in high-speed transitions through manipulation of the toe settings. Care must be taken because Pilot Sport Cup tires generate significant levels of lateral force even at very small slip angles; thus, large toe-out or toe-in settings can have big effects. In general, a good starting place is near zero toe (parallel) or the minimum value of the factory spec for toe-in at the front axle. At the rear axle, moderate toe-in (usually the minimum factory spec for toe-in) is not a bad place to start.

Tire Pressure Recommendations
Pilot Sport Cup tires generally provide their best performance when running somewhat lower tire pressures than other brands of DOT-legal competition tires. The guidelines presented below are for relatively light vehicles; heavier vehicles will require additional inflation pressure.

General Guidelines for inflation pressure are as follows:

Road Use: Vehicle’s placard pressures.

Road Racing/Drivers Schools/Track Events: Typically 25-28 psi cold rising to a target of 32-36 psi hot.

Autocross/Solo II/Solo I: Typically target of 32-36 psi hot. Autocross applications will need to start at higher cold inflation pressures due to the decreased tire pressure gain experienced during autocross events (compared to road racing).

Damp/Wet Track/Course Conditions: For both autocross and track use in heavy wet conditions (lots of water down on the course), increasing tire pressures as much as 6-10 psi hot above what would normally be run in dry conditions may be necessary for best efficiency. For "damp" conditions (course is wet, but no standing water), pressures at or slightly higher than the high end of dry-track recommendations will likely be most efficient. Car setup and driving style in the wet is very important, so some experimentation may be in order.

Tire Break-In Procedures/Heat Cycling
When used on a racetrack, tires should be scrubbed-in at the beginning of every track session. This is done to build tire pressure as the tires heat up while removing the mold release coating found on new tires and debris previously picked up by a used tire.

Heat cycling can be performed mechanically at The Tire Rack before the tires are shipped or by driving on them after they have been installed. It is important to remember that the 24 to 48 hour "resting" period for the tire following heat cycling is an important element to the process' success.

Tire Temperatures
Tire temperatures will vary from track to track. The tread compound’s most effective temperatures are in the 160 - 220°F range. Use of a tire pyrometer will provide tread temperature information that will indicate the appropriate suspension settings and tire pressure adjustments needed to maximize performance.

Experiment with one axle at the time. Do NOT change too many variables at one time.
 

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