Kumho controls race tire pressure with Quadrapuss

March 27, 2007

With its black tank, blue gauges and tangle of tentacle-like hoses, Kumho Tire U.S.A. Inc.'s "Quadrapuss" looks more like a sea creature than a piece of equipment used to fill race tires with nitrogen.

But the new Intercomp Tire Drying/Purging System enables Kumho tire technicians to fill race tires with nitrogen while precisely controlling the relative humidity inside of the tires. It was first used at Sebring International Raceway during a recent ALMS (American Le Mans Series) event.

"Humidity directly affects how much pressure race tires gain as they heat up," says Rudy Consolacion, Kumho's motorsports manager. "If there's more humidity in the tire, the air pressure will rise more as the tire heats up. And the more the air pressure rises, the more the tire heats up.

"It's a vicious, intertwined cycle. But the Intercomp system enables us to better control that cycle."

The system consists of four hoses (one for each tire), a couple of pressure gauges and air valves, and a tank with a moisture filter. To use the system, the tires are:

1. mounted and inflated with regular air;

2. connected to the Intercomp hoses; a vacuum system evacuates all of the air and humidity from the tires, literally collapsing them on the wheels;

3. inflated with nitrogen that has been run through the moisture filter.

"The benefit of using nitrogen is that it's a much more stable gas than regular air, so tire pressures don't increase as much as the tires heat up," says Consolacion. "Running the nitrogen through a moisture trap helps make it even more stable.

"In racing, we may see pressure gains of 15 to 18 psi in each tire when we use air, but with nitrogen that's been run through the moisture trap, we may see gains of only 10 to 12 psi. This helps the tires stay cooler because we don't get excessive growth in air pressure and the subsequent growth in temperatures."

Before using the Intercomp system, Kumho had about 30% humidity in its race tires. At Sebring, the Kumho teams' tires had about 1%.

"The biggest benefit with this system is that it's helping us accelerate our tire development process by eliminating known variables that can lead to misinterpreted data," he says.

As for the Quadrapuss nickname, Consolacion says one of the guys in the Kumho trailer came up with it, "and we figured if the name fits, wear it."

Kumho is competing in the LMP1 class with Intersport Racing for the 2007 ALMS season.