GM Racing 2004 review

Beadlock Design Improved Both Safety And Performance in 2004 INDIANAPOLIS, Nov. 29, 2004 - The first full season of Pro Stock cars racing with the 16-inch beadlock wheel has just been completed, and after the 2004 pre-competition concerns over...

Beadlock Design Improved Both Safety And Performance in 2004

INDIANAPOLIS, Nov. 29, 2004 - The first full season of Pro Stock cars racing with the 16-inch beadlock wheel has just been completed, and after the 2004 pre-competition concerns over the new design, the numbers indicate that both the safety and performance of the vehicles improved. Beginning with the 2004 Winternationals all Pro Stock wheels were required to meet a minimum SFI Spec 15.1, measure 16 x 16 inches and be of beadlock design. After 23 contested events it appears that the proactive stance taken by NHRA to enhance a vital area of safety for the Pro Stock cars was successful.

"At GM Racing, we always encourage and promote initiatives that are proactive when it comes to safety in motorsports," said Tom Gideon, GM Racing Safety Manager. "You can never be perfect when trying to anticipate the likelihood of a specific event occurring, but you can take a good hard look at the variables you do have to work with and make solid predictions based on relevant probabilities. Instead of waiting for a problem to occur with the Pro Stock wheels, the NHRA and Goodyear took steps toward prevention and we applaud their efforts in implementing the beadlock design."

The need to switch over to the beadlock wheel became increasingly evident with the Pro Stock categories' continued acceleration above the 200-mph barrier. Working closely with GM Performance Parts Pontiac driver Warren Johnson, engineers at Goodyear came up with a tire and wheel design during a series of tests in 2003 and early 2004.

"It was quite obvious that we needed to do something," said Johnson. "We saw a number of drivers get upside down in the 18 months or so prior to the change and all of those incidents could have been averted with the beadlock tire. The beadlock tire by its very nature has a lot more lateral stability because the bead is locked to the wheel, coupled with the fact that by lessening the amount of sidewall in the tire, that contributes to its lateral stability as well."

Johnson adds that with the rigid assembly of the beadlock wheel and the way the tire is fastened to it, the design makes a Pro Stock car less prone to tire shake.

"The conventional method we used in year's past was just a bunch of sheet metal screws attaching the tire and the wheel together," explained Johnson. "Not only was it archaic, it was highly unsafe. There have been numerous pictures over the years that show a car making a burnout with the tire barely touching the rim - it's sucked right off the bead area. In a tubeless configuration all you need is to break that seal just a little bit and you have a tire that's flat."

As the Pro Stock cars began inching their way above the 205 mph barrier, engineers from The Goodyear Tire & Rubber Company began pushing the beadlock design with NHRA and various race teams.

"As you get higher centrifugal forces and vertical forces on the tire, the bead wants to pull away, and essentially generates more force to pull off the screws and away from the bead," explained Goodyear's Dave Auffenberg. "With the beadlock, you basically secure that bead between the rim and the beadlock ring so that it is essentially locked into place. It can't move during the course of the run, assuming of course that it is mounted properly. The bead doesn't move so all of your forces are going into the performance aspects of the tire. You also don't have to worry about the tire coming off the wheel and possibly losing air during the run."

Auffenberg notes that with the Pro Stock cars, Goodyear had a good baseline to begin with based on the design and work done over the years in the Top Fuel and Funny Car categories.

"That was kind of our starting point," explained Auffenberg. "Some of the basics in the original tire size for the Pro Stock category were based on tires used in some of the faster classes. The construction that we ended up with for the Pro Stock cars was developed from a lot of the work done on the cars with the 15-inch tire. The beadlock concept really has come into play quite a bit with our work with Top Fuel and Funny Car, and somewhat with the Alcohol and Pro Mod classes. Those classes are running faster than 200 mph, so the successful aspect of it really has come from a lot of work done with cars running quite a bit faster than a Pro Stock car."

Many Pro Stock competitors like the new beadlock design because it reduces tire spin, partly because of the extra footprint, and partly because of Goodyear's construction package. The stability of the beadlock design helps keep a Pro Stock Car from getting loose, even when it ventures out of the groove. It also prevents the cars from running on the so-called "ragged edge" providing drivers with an increased level of comfort and security.

"If you look at the whole season there's no question that the beadlock tire/wheel combination calmed these cars down," said Summit Racing Pontiac Grand Am driver Greg Anderson. "We didn't have any cars flip over this year and we didn't have the kind of incidents that we had at Columbus in '03 - nothing even close to that. The new tires made the cars more stable, we had more side-by-side racing, fewer aborted runs and it created a comfort factor in your mind when you got in the car. "The extra stability of the larger tire also meant more times down the racetrack, and more data we were able to gather. Therefore we were able to learn more. Everybody made more laps this year because we didn't have the number of aborted runs that we had before, and that's because of the more stable wheel-tire combination. We're able to go after it more aggressively because the beadlock combination will take more."

One of the concerns among Pro Stock competitors at the beginning of the season was that the switch to the heavier tire/wheel combination would drastically reduce performance in the category, creating a less interesting show for the paying spectator. But a comparison of this year's performance numbers to the times and speeds generated in 2003, actually show an improvement.

In 2004, the No. 1 and No. 16 qualifiers posted quicker times in 17 of the 23 events contested (74%) when compared to results taken from 2003. Low elapsed time of the meet was quicker at 18 events (78%) and top speed of the weekend escalated at 18 races. Furthermore, the national elapsed-time record was lowered to 6.661 seconds from 6.670 seconds, the top speed was raised to 207.75 mph from 207.18 mph and 12 drivers ran in the 6.60s for the first time compared to just one driver in 2003.

"We fought it a little bit in the beginning because we were concerned the cars would slow down, but just the opposite happened," explained Anderson. "Enough gains were made power-wise and performance-wise that we made up for it. Even with the heavier wheel, the cars are still faster than they were last year. It's an absolute plus, it was a good idea and it was the best thing to do. It's made these cars safer, more stable and they'll be more stable as the power level goes up. If we were still on last year's wheel, these cars would be getting more edgy and that's a safety compromise our families shouldn't have to live with."

Johnson, one of the major proponents of the 16-inch beadlock wheel, sees the design as a factor that will actually contribute to better e.t. and faster speeds in the long run.

"These cars are much more stable and you can drive them around the racetrack better," explained Johnson. "When you get out of the groove you don't have as much of a phenomenon of the car trying to pull itself further out of the groove. With the bigger footprint on the ground, the tendency to spin the tire down track is a lot less. We can get a lot more aggressive with the clutch setup and the gear ratios as far as 60-foot times are concerned. I think if you were to go back and compare the 60-foot times from a year ago, our 60-foot times this year were significantly better with the beadlock combination."

With the proven effectiveness of the beadlock design, criticism has subsided, but Goodyear continues to work with the Pro Stock teams in an effort to evaluate new concepts and ideas with the ultimate goal of producing an even better design.

"When it comes to performance we want to stay ahead of the curve and that was the purpose of going to the beadlock design for the Pro Stock cars," said Auffenberg. "Now that teams have had an opportunity to work with it, we've gotten a lot of favorable comments. We've given our feedback and have tried to keep everybody moving in the right direction. We've been very satisfied with what we've been able to do and the results of having the tire out there this year."

The six-time NHRA Pro Stock champion continues. "Everyone felt that the beadlock wheels would slow the cars down, that they would be unsafe, that they didn't have the weight to take out of the car, because the tire/wheel combination is certainly heavier. The bottom line is that we had better performances all year and we didn't have any incidents of cars getting into trouble on the racetrack. Overall, it was win-win situation."

-gm racing-

Be part of something big

Write a comment
Show comments
About this article
Series NHRA
Drivers Warren Johnson , Greg Anderson