The belt is one of the most abused parts on your car. It is expected to sit there at an idle while the clutch is spinning at thousands of RPM. At the hit of the throttle, it has to grab hold of the primary and secondary clutch to make the car move. As the clutch shifts, the belt also has to slide up the primary and down the secondary clutch without slipping. This action has to be the same every time, for the car to be consistent.

To better understand Polar Belts, let's take a look at how they are made. It begins as a three or four feet wide sleeve on a mold or drum. The belts are then cut from this sleeve. One sleeve might yield 30-40 belts. A lubricant is used to keep the cutting tool from sticking to the rubber.

All new belts will have some residue from the lubricant on the sides that touch the clutch shieves. This residue will wear off, but it could take 8-10 runs to fully clean the sides of the belt. On higher horse powered cars, this will probably be seen as some black on the shieves, along with increased slippage. The ET will be reduced until the belt is "broken in." The black on the clutch should be removed using a rag dampened with Acetone. On a new belt, scrubbing the sides of the belt with hot soapy water and a bristle brush will help. Use laundry detergent for the soap, because it is strong and will help remove the lubricant. This only helps; it is not a total cure. It will still take several runs to break in the belt.

When a belt is new it is stiffer. As the belt is used it will become more flexible and transfer power more efficiently. This will take 6-10 runs and will continue to improve slightly for the next 10. It would be best to buy a few belts at a time. Clean the belts then run them on a test day or put them on a lower horse-powered car to break in the belt. If you do several at a time this should produce more consistent belts on race day.

Polar recently released a new 9" center-to-center belt with part number 33188AR. This new belt and the 33188A are made of the same material. The newer 33188AR belt is .01" wider than the 33188A belt. The 33188AR belt has also been trimmed slightly at the top to reduce the chance of peeling off the cover. This is done manually, so it is not consistent. If you measure the top width with a caliper, you will get a false reading. To get a true reference, you can use the secondary clutch and measure the amount of belt that sticks out of the shieves. This will help you compare belts. The amount that sticks out determines the width - the higher the standout, the wider the belt. See the picture at the bottom of the page.

We hope this information will help you better understand and utilize our belts, so we can keep you in the Winner's Circle.

Fig. 01 | The standout of the belt is the best indication of the width.

Fig. 02 | Scrub the belt well, to remove any residue.