Creating a heads-up racecar is truly an exercise in maximizing everything on a vehicle, from the front bumper to the parachute hanging off the back. To be competitive, all parts of the car have to be evaluated and improved to get the biggest advantage, and this includes the wheels. The Project Evil Mustang needed some new shoes so we turned to Billet Specialties for their race-bred Comp 7 wheels to gain the edge needed for X275 racing.
Our Project Evil Mustang has been going through some changes recently as it’s transformed into an X275 machine. Besides the new small-block Ford from KBX Performance, the car also picked up some new shoes in size 275 from our friends at Mickey Thompson and that rubber needed a new home. The Comp 7 wheels from Billet Specialties were a great choice since the company’s goal with these wheels is to provide customers with improved performance that comes in a stylish package.
Before Billet Specialties fired up the machines to start cranking out wheels, they took a look at what the market really wanted and needed. Scott Sandoval from Billet Specialties explains the mindset behind the design process of the Comp 7 wheels.
“Our customers are some of the nation’s top custom car builders — the trendsetters you could say — and paying attention to what styles from our custom two-piece line are popular played a big part in the design. Transferring that styling to our race wheel line only made sense.”
The Comp 7, as well as the other wheels in the Comp Series line from Billet Specialties, is designed for drag racing only. To enhance the Comp 7 wheel for drag racing, Billet Specialties took the weight of the wheel into account to ensure it would accelerate with a minimal amount of inertia. The wheels also went through rigorous testing to earn an SFI certification for the highest level of safety.
Because removing weight and adding strength is critical to a build like our Evil Mustang, what the parts are made of that we use is critical. Billet Specialties selected forged 6061 T6 aluminum for strength and a spun aluminum outer material for weight savings. This provides the wheel with a great run-out that’s important to building a wheel that has strength while keeping the weight down.
“Having superior lateral and radial runout is very important for a high-end racing wheel. Any vibration or variance in the rim can contribute to, or cause, tire shake and wheel hop. The best practice is to make the wheel right and offer the customer one less thing to adjust for,” Sandoval explains.
Drag racing provides a unique set of challenges for wheel manufactures; one of the bigger obstacles is how to keep a tire from slipping on the wheel. A car like Project Evil is going to try and push as much power to the track surface as possible, and to keep those Mickey Thompson tires on the wheel Billet Specialties added a knurled inner surface to prevent tire slip.
“The knurling assists the crush of the bead bundle in keeping the tire clamped properly to the wheel. Crush is the amount the rings will squeeze the bead bundle of the tire. Tire bead bundles can vary from tire to tire and manufacturer to manufacturer; our bead locks have a .500-inch gap when closed. The tire bead needs to be at .6-inches or thicker to seal and grip. A tire needs to have .100- to .125-inch crush to seal properly,” Sandoval says.
Project Evil is entering the home stretch of this latest batch of upgrades to get ready for some X275 racing. Get caught up on everything that’s been done to the Mustang right here and be on the lookout for more, including its debut in X275 trim very soon.