The driver's side on all Car of Tomorrow vehicles now features double frame rails. The drive shaft is now encased in a steel tube to prevent it from piercing the floor pan and impaling the driver in a crash.

NASCAR tests the chassis/rollcage assembly for each team, recording the location of each joint, component and measurement.

Every joint and mating of the rollcage and other components must fall within tolerances outlined in the Car of Tomorrow construction plans developed at the NASCAR R&D Center.

While the Car of Tomorrow is highly standardized through specifications and certification testing, the fabricators on the various racing teams aren't really as locked in as one might think, Krueger says.

“We control the big pieces, but there's a lot of flexibility in terms of suspension geometry and how components are attached to the chassis. There is room for manufacturer identity. The pick-up points on the chassis are regulated only for asymmetry requirements,” Krueger said.

Love and his counterparts on other racing teams admit there isn't much “wiggle room,” but also acknowledge Car of Tomorrow specifications do allow for strategic modifications.

“It was a challenge at first, but we stopped objecting to the concept and started to think creatively inside the box. We decided we needed to find ways to get the most out of the Car of Tomorrow design requirements,” Love said.

Welding within the box

Welding is one of the great dividers when it comes to customizing the Sprint Cup Series Car of Tomorrow among racing teams and automotive manufacturers.

“Each car gets a personality through the slight variations of tubing thickness, the alloy, the welding method and even the welder who worked on it. One guy welds differently from the next one,” Krueger points out.

A stock car chassis requires thousands of welds. Some chassis are completely gas-metal arc (MIG) welded, while others feature a combination of gas-metal arc and tungsten gas-metal arc (TIG) welds. Some teams even tinker with the concept of using only the tungsten gas-metal arc process for their chassis, Krueger said.

While time consuming, tungsten gas-metal arc welding produces a cleaner weld and uses lighter-weight materials than gas-metal arc welding. Those factors have caused NASCAR fabricators to take an increased interest in tungsten gas-metal arc welding, even if the welding process takes longer.

“Weight always has been an issue, even pre-Car of Tomorrow,” Krueger said, adding that the total weight of cars on the track today is mandated by Car of Tomorrow guidelines.

“Teams always are trying to save weight at the top of the car. Anywhere you can take even an ounce off the chassis, you do it. If a TIG weld saves an ounce or two of weight, it might be worth the extra hours,” Krueger said.

At Joe Gibbs Racing — a shop that uses Lincoln Electric equipment exclusively — Love and his team try to incorporate as much tungsten gas-metal arc welding into chassis construction as possible.

“We want the best-penetrating, most-consistent weld we can make,” Love said.

“Obviously there is a time issue in motorsports, but we want everything to be perfect, too. TIG is my preference, but I also think the highest form of motorsports should perform with the highest form of welding,” he added.