"AIR
PRESSURE" "AIR
PRESSURE"
THIS MONTH I'M GOING TO TALK TIRE AIR PRESSURE.
OVER SEVERAL EVENINGS OF RACING I'VE ASKED FELLOW RACERS WHAT KIND OF TIRE AIR PRESSURE THEY HAD RUN OVER THE COURSE OF THE EVENING. MANY WERE SIMILAR TO MY SET UPS AND SOME WERE WAY OFF, BOTH TO THE FASTER AND SLOWER SIDES.
I HAD A CHANCE THIS SUMMER TO TALK TO FRANK HAGER WHO IS NOT ONLY A VINTAGE STOCK CAR RACER BUT A REP FOR BF GOODRICH. WHEN TALKING AIR PRESSURE I WAS TOLD THAT BF HAD FOUND THAT 12 LBS WAS THE MINIMUM THAT A TIRE COULD BE RUN AT AND BE EFFICIENT. AS WE ALL KNOW THE PERFECT WORLD AND THE REAL WORLD VERY SELDOM CROSS PATHS.
WHEN DETERMINING PROPER AIR PRESSURES THERE ARE MANY FACTORS TO TAKE INTO CONSIDERATION. THINGS LIKE DO YOU RUN BEADLOCKS, TIRE WIDTH TO RIM WIDTH, TYPE OF TIRE, HOW HEAVY THE CAR IS, FLAT OR BANKED TRACK, TRACK LENGHTH, SURFACE, WHAT THE CARS IS DOING, WHAT YOU WANT THE CAR TO DO.
BEADLOCKS NOT ONLY ARE A HUGE SAFETY ITEM BUT THEY ALSO ALLOW YOU TO RUN LOWER THAN NORMAL PRESSURES WHEN NECESARY AS WELL AS RUNNING TIRES THAT ARE WIDER THAN THE RIM AT REALLY LOW AIR PRESSURES OFFERING A GREAT AMOUNT OF SIDE BITE IF YOU CAN GET USED TO THE "WOLLERING" EFFECT IT GIVES! BECAUSE OF THE GREAT AMOUNT OF SIDE WALL FLEX THE ENTRY TRANSITION OF THE CAR IS ALMOST DELAYED AND GIVES THE DRIVER A MOMENT TO CATCH UP. SOME DRIVERS FIND THAT MOMENT OF DELAY UNNERVING. IF YOU CAN GET USED TO IT YOU CAN REALLY FLY ON CERTAIN TRACKS, ESPECIALLY THE FLAT, 1/4 MILE KIND OF STUFF OR TRACKS WITH OFF CAMBER CORNERS.
I CAN'T TELL YOU WHAT YOU NEED BUT I CAN TELL YA WHAT I RUN. MOST TRACKS MOST NIGHTS I START THE HEATS WITH RR:10-12 LBS, LR:8-10 LBS, LF:10-12 LBS, RF:15-13LBS. NOW HERE IS THE KICKER...I KNOW A SUPERMOD CAR WHO IS LIGHTER, LOWER, AND MORE POWERFUL THAN ME THAT RUNS 20 LBS IN THE REAR AND AROUND 16-18 LBS IN THE FRONT.
CONFUSED YET? IF YOU'RE NOT YOU'RE FOOLING YOURSELF. HERE'S A SECRET I LEARNED A LONG TIME AGO. BASICALLY THIS IS HOW I'VE MATCHED TIRE PRESSURE WITH MY SET UPS FOR SOMETIME. IT'S AMAZING HOW MANY PEOPLE DON'T DO IT! WHAT YOU NEED TO DO IS SET YOUR PRESSURES AT WHAT YOU THINK YOU WANT. TAKE WHITE SHOE POLISH AND APPLY ABOUT A 5" INCH STRIPE OF IT FROM THE RIM TO THE FLAT OF THE TREAD ON THE OUTSIDE OF THE RIGHT SIDE TIRES AND THE INSIDE OF THE LEFT TIRES. WHEN YOU COME IN FROM A RUN YOU CAN SEE IF THE TIRE CONTACT PATCH WAS FLAT OR ROLLED OVER ON THE SIDEWALL. DOESN'T TAKE AN EINSTEIN TO FIGURE WHICH IS MORE PRODUCTIVE. GIVE IT A TRY AND TELL ME IT DIDN'T HELP!