Tech Bulletins

CURRENT COMPOUND SELECTION AND APPLICATION GUIDE

The compound number can be found in the serial number on each tire.

EXAMPLE: CY1J M5 FJ087 M5-Compound code.

Mickey Thompson tires are compounded by size and application. The following points are general application suggestions.

Mickey Thompson is not responsible for misapplications.

The catalog number suffix indicates a construction, size or compound enhancement for particular applications.

R - Radial construction

M - Motorcycle

C - FWD / Sport Compact

ST - Suggested for manual transmission (Medium compound – M5)

W - Extra tread width (please note actual tread and section width on spec sheet)

S - Stiff sidewall construction. Recommended for 4 link suspension cars, heavy cars (over 3000lb.), and “soft ride” Rear Engine Dragsters. Can aid in quicker reaction times due to less tire distortion.

MICKEY THOMPSON COMPOUND SELECTION CHART

Medium - Soft: M7 X5 M5 L5 R2 R1 X8 L8 X7 L7 L4 L2

L4 – Soft compound for Dragsters, lightweight vehicles and vehicles without rear suspension.

L7 – For motorcycles.

L8 – Good compound for general use.

L2 – For Jr. Dragsters.

L5 – Good for High Horsepower – Boosted Applications

M5 – Good compound for general use.

M7 – Good compound for general use.

X5 – Cooler running version of M5.

X7 – Cooler running version of L7.

X8 – Cooler running version of L8.

R1 – Special Compound for ET Drag Radial.

R2 – Special Compound for ET Street Radial.

BURNOUTS– FOR MOST APPLICATIONS

The length of your burnout will be dictated primarily by the ambient and track conditions. The hotter the temperatures, the shorter the burnout. When the temps get cool, a longer burnout will be necessary. Ideally you want the tire temp to be within 15 degrees of the track temperature on the launch. When the track temps exceed 120 degrees, it is always best to keep your tire temps on the lower side. Here are some additional tips for maximizing the performance of your M/T racing tires.

1. First pass of the day will be your longest. After that follow the guidelines of #2 and #3 stated below.
2. Automatic transmissions and Bias tires with Softer compounds: First pass or two, fairly hard burnout relative to ambient conditions. After that a light burnout should be sufficient.
3. Standard transmission and Radial tires: Typically shorter burnouts are better. A light burnout, enough to haze the tires, then stage immediately.
4. No dry hops. This does nothing to improve traction, and in some cases can have a negative effect.

ET Street™ R (Bias), ET Street® R, ET Streetl® S/S, Pro Drag Radial, Pro Bracket Radial and ET Drag® Air Pressure Guidelines

PROPER AIR PRESSURE

Proper air pressure is critical to the best performance of your ET Drag or ET Street racing tires. Mickey Thompson strongly suggests investing in a good tire pressure gauge and that you keep accurate and complete records of each pass. This will aid you in becoming a consistent performer. Recommending air pressure is not easy, since there are so many variables that affect it: i.e. weight distribution, transmission, chassis set-up, wheel size, etc. To help you, we have broken down the types of vehicles into the following categories with a recommended starting point for the correct air pressure. These pressures are for off-highway use only and based on optimum chassis and drivetrain setups. Keep in mind that these are purely starting points. Actual optimum air pressure may vary significantly. If you have been running another brand of slick on your racecar, we generally recommend you start with the same air pressure you were running and go up in ½ pound increments until you get the best performance. Most racers will usually end up with ½ to 2 pound more air pressure in a Mickey Thompson tire. Note: Many racers feel that “Less is Better” with regard to air pressure. This is not always the case. While there are exceptions to every rule, we have found higher pressure generally works best with Mickey Thompson Tires. Not only do the higher pressures lead to quicker times, but they also contribute to a safer, more stable ride at the finish line.

ET DRAG PRO DRAG RADIAL AND PRO BRACKET RADIAL

• When working with ET Drag Radials use 1 psi adjustments to see change.
• A radial will perform quicker the more air you can run.

ET DRAG MOTORCYCLE

• Quarter Mile: in 8 to 9 seconds, 15 – 19 psi
• Quarter Mile: High 9 seconds and slower, high twenties to mid thirties
• 3210 ET Front: 35-40 psi
• 3053M, 3158M (Pro Stock – Pro Mod): 4.0 – 6.0 psi, wheelie bar 2” – 2 1/8”
• 3064M: 4.0 – 6.0 psi, Wheelie bar 2” – 2 1/8”
• 3065M: 6.0 – 9.0 psi, Wheelie bar 1 ¾”
• 3073M: 7.0 – 8.0 psi, Wheelie bar 1 ¾”
• 3220: 7.5 – 10 psi, Wheelie bar 2” – 2 1/8”
• 3221, 3222: 6.5 – 8.0 psi, Wheelie bar 2” – 2 1/8”

These recommended pressures are guidelines only, actual pressures may vary. Wheelie bar settings are with the front end extended and can vary as well.

ET STREET™ R (Radial) AND ET STREET™ S/S

• On the racetrack DO NOT use starting pressures below 13 psi.
• Recommend pressures: 14-18 psi
• For suggested highway use inflation pressure in Mickey Thompson ET Street Radial tires, contact the Mickey Thompson Tires tech * department at (800) 222-9092 (Option 5).

Please have your OE specified tire size and OE cold inflation pressure (located on the vehicle’s tire placard), as well as the new tire size available for the tech staff.

ET DRAG JR.

• 3625: 4 – 8 psi
• 3645: 4 – 8 psi

The technical information provided in this document is to be used purely a guideline. Due to the many varied and different conditions to which racing tires, wheels and tubes are exposed, and because of the manner in which racing is conducted, Mickey Thompson Performance Tire makes absolutely no warranty, expressed or implied, as to the fitment for a general or particular purpose. Racing Tires are Sold As Is.

Mickey Thompson® D.O.T. And Non-D.O.T. Drag Racing Tires Extended Storage or Winter Storage

STORAGE PROCEDURES AND TIPS

1. Remove the tires from the car or jack the car up to remove the load.
2. Drop air pressure to 5 pounds.
3. Keep the tires away from direct light (sun or fluorescent). It is best to keep tires covered.
4. Keep tires away from electric motors I.E. furnace, air compressor, etc. These create OZONE, which will damage the tire.
5. Mickey Thompson suggests that you keep tires away from extreme high and low temperatures.
6. Do not use any chemicals on the tires. To clean them use a mild detergent and water. Rinse well. Do not clean the tread surface.
7. By following these simple precautions you will get the best service from your tires. If you experience inconsistent 60? & 330? times the next season, it’s probably time to replace the tires.

Mickey Thompson Natural Rubber Racing Tubes

Besides being required for air retention, Mickey Thompson racing tubes can enhance reaction time, increase stability and helps the tire maintain the proper shape to reduce sidewall shock and deflection.

Note: Always run the correct size natural rubber tube for the application. The wrong tube type and size will always fail.

When buying tube type tires it is important to understand the reasons behind making a tire tube type and when it is appropriate to run the tire with or without a tube. The decision to run with or without tubes should be based on safety and performance, not cost.

The following information will elp in the decision making process

1. Air retension Tube type tires are not guaranteed to hold air without a tube. If a tube type tire leaks, it is not defective. Tubeless tires use a liner molded into the carcass for air retention. This liner is usually omitted from racing tires, primarily for weight purposes.
2. Consistency A tube aids in maintaining consistent air pressure. Therefore if consistency is the primary goal, as in Bracket Racing, a tube is always recommended.
3. Strength The use of tubes makes the tires package more robust. This really comes into play with heavier vehicles running smaller tires. Because of this, they can extend the life of the tire saving money in the long run.
4. Weight & performance In some cases it is acceptable to run a racing tire without a tube. When a car competes in a heads up class, unsprung weight, like a tire and tube, is an important factor This is especially true when it comes to a limited power combinations such as naturally aspirated engines. One pound of “unsprung” weight is equal to 8 pounds of “sprung” weight. Based on that, every 12 pounds of unsprung weight removed may gain as much as .01 seconds in quarter mile ET.
5. Cost All M/T tubes are made of Natural Rubber and feature a clamp down valve stem. There are some inexpensive Butyl rubber tubes on the market, even with clamp down valve stems. Natural rubber is, by far, the better choice. It conforms to tire distortion better, dissipates heat, and it doesn’t get brittle like butyl rubber. Therefore M/T natural rubber tubes offer superior performance and will last far longer with the ability to be re-used.
6. Safety At a racetrack you must check air pressure regularly. This is important to maintain performance and to insure pressures are not too low. Low pressure can be dangerous. Never run tube type tires on the street without a tube. Leakage and the prolonged heat build up can lead to tire failure, serious injury or death. This is not a matter to take lightly. MOUNTING PROCEDURES FOR TUBE TYPE TIRES
7. Check the valve stem hole in the rim. The hole must be 5/8. Note: If necessary to drill the valve stem hole in the rim, make sure the rim is de-burred and free of material and sharp edges.
8. Before installing new tubes pre-inflate the tubes to the approximate diameter of the tire. This will aid in filling the entire cavity of the tire by giving the tube a “stretch”. Note: This will also aid in valve stem placement on wide rims where the valve stem is offset on the rim, but not on the tube.
9. Clean the bead and all interior surfaces of the rim.
10. Place wheel on tire changer following the equipment manufacturers instructions.
11. Mount bottom bead only on the wheel.
12. Insert tube in tire and partially inflate to make sure it is not “twisted”. It will help to lubricate the tube with baby powder. If you’re using a liquid lubricant on the bead, do not allow lubricant to run between the tire and the tube. DO NOT use anti freeze, silicones or petroleum based lubricants.
13. Align the tube valve with the valve stem hole in rim. Insert and center the stem in the hole.
14. Mount the top bead of the tire on the rim so that the bead in the valve area is the last part of the bead to go over the rim flange. Be careful not to pinch or move the tube. Re-center the valve stem, if necessary, by rotating both the tire and tube. After centering the valve stem install the valve stem clamp ring.
15. Inflate tire assembly slowly to seat tire beads. Do not exceed 35 p.s.i. to seat beads.
16. To prevent tube wrinkling, remove valve core to completely deflate the tube. Reinsert valve core and firmly seat it. It may be necessary to repeat this process to eliminate any wrinkles. Note: See second half of this bulletin for further details.
17. Reinflate assembly to proper pressure and check circumference of the tires to make sure they match before installing any rim screws into the tires. You may notice a “low spot” or “wrinkle in a tube type tire. This can be caused by one of the following: A. Wrong tube size (too large or too small). B. Faulty tube installation (wrinkles in tube). To confirm the problem, you can do one of two things:
18. Break the tire down and rotate it on the rim. You’ll note that the low spot, if it is still there, has not moved.
19. Break the tire down and remove the tube. Install a valve stem and inflate the tire. You’ll note there is no low spot. To correct the problem, first be sure the correct tube size is used. The proper tube is listed in the Mickey Thompson spec sheet. To eliminate wrinkles, the tube should be inflated and deflated during installation. If the wrinkle persists, you may need to lubricate the tube with baby powder and/or break the tire down and work the wrinkles out by hand. Note: If the wrinkles are not removed or the wrong tube size is used, premature tube failure will occur.