Being competitive in today's racing environment means that every aspect of a race car must be scrutinized for optimum performance. Serious competitors don't have the luxury of leaving even the smallest detail to chance. This is true for the Saturday night warrior or a Winston Cup team. Because of this, a number of new sciences have developed in the racing community, which serve as a testament to the specialized nature of race car building. Among the most advanced sciences is that of chassis building.
There can be little argument that chassis design has reached a pinnacle of importance never thought possible as few as five years ago. With a world of technology available, today's chassis builder has an extraordinary amount of information on which to base any new scheme. With such an abundance of resources it seems impossible that it can all come together to produce a superior race car platform.
Speaking with three chassis experts, we wanted to know how different builders approach chassis building. Our goal was to understand how a race car foundation moved from a theoretical concept to reality. Along the way, we also looked for information or new ideas or concepts that might provide some insight into the direction chassis building is headed.
Eddie Dickerson, Director of Chassis Engineering at Hendrick Motorsports
First, we took our questions to Eddie Dickerson, who is director of chassis engineering at Hendrick Motorsports. Dickerson and his staff have been at the cutting edge of chassis design for 11 years and are well known for their successes with the #5, #24, and #50 Winston Cup cars.
Beginning with the basics, we took a look into materials used in the building of the Hendrick chassis. From a materials standpoint, NASCAR mandates the basic components. The rules set the material types and minimum material sizes. As an example, framerails are required to be a minimum of 3x4-inch rectangular tubing with .120-inch thick wall. The main structures (cages) are constructed from 1 3/4-inch-diameter .090-inch-wall seamless tubing. Other materials are always being investigated, but NASCAR has tightened up the rules so not much room is available for big changes. As a matter of fact, Dickerson told us that many of the chassis rule changes came about because of the #24 car the Hendrick stable ran in Charlotte in 1997. That car, known as T-Rex, was legal, but because the design pushed the envelope a bit too much, the NASCAR rulemakers changed some things to try to standardize chassis making. Dickerson said, "Chassis design has some tight baseline standards today, but you have to be on your toes looking for areas to improve your system."
From a philosophy standpoint the Hendrick organization takes the approach of maximizing the performance of the chassis before making any big changes for performance gain.
NASCAR mandates chassis materials used in the Winston Cup Series. Many other series requir
"Except for the T-Rex, our basic chassis is similar to the ones run in years past," Dickerson said. "It has been a slow and evolving process over the years. The changes have been a little here and a little there. Our basic foundation is based on the same points as the Ronnie Hopkins and Mike Laughlin cars. Taking those points as the standard, we have developed our chassis based on incremental changes. Making big changes can be very tough, because for every alteration you want to make you are faced with other things that may make it impossible to try something new. The basic packaging of the race car does not leave a lot of room for radical changes. Our philosophy is to get 110 percent out of what we have before we go to some different ideas. Of course, that does not mean that if we see something that can give us a superior setup we won't pursue it. We didn't just fall of the turnip truck-our engineer and staff are constantly providing us with new things to look at."
There are a lot of ways to work and re-work a chassis to search for things. Today, Hendricks is looking more in the area of the snout.
"We have developed a short-track snout and an intermediate-type speedway snout that works pretty well for us," Dickerson said. "When it comes to changes, the front suspension seems to be where we can find more. The rear tends to be an area that provides less opportunity for improvement."
Driver comfort is still a part of the chassis mix. Each of the Hendrick drivers-Gordon, Labonte, and Dallenbach-have a certain feel they want with their cars. That means Dickerson and company must provide changes here and there to accommodate the style of the drivers.
"Fortunately for us, we have 15 people on site that are always thinking to come up with new things," Dickerson said. "Some of what we do is an educated guess, but you still have to get on the track to do the good-ole-boy testing. Even after you have built the best chassis, something as simple as tire compound or sidewall rigidity in track testing can give you very different driving characteristics than what was expected. It's always a challenge."