Stratasys Is Printing Next-Generation Racing Parts for NASCARStratasys Is Printing Next-Generation Racing Parts for NASCAR

3D printing has become such a crucial technology for NASCAR that Stratasys has inked a deal with the race series to provide the NASCAR R&D center with the latest state-of-the-art equipment on a rotating basis, ensuring that the engineers at the center will always be using the best devices available.
At the same time, multi-time champion Joe Gibbs Racing has stocked its shop with Stratasys machines that it uses for making test parts that the team uses in the wind tunnel and at the track.

The Stratasys deal supplies the NASCAR R&D center’s new 3D printing lab with new F370, 450mc, F900, and NEO800 printers so that the staff has access to a variety of technologies and materials for producing test parts. NASCAR also 3D prints a pair of standardized vents it supplies the teams that must be used exactly as they are provided from the R&D center, straight off their printers.

Opening the NASCAR R&D center's new 3D printing lab. STRATASYS

“Partnering with Stratasys allows NASCAR to push the boundaries of performance and accuracy like never before,” said John Probst, Executive Vice President, Chief Racing Development Officer at NASCAR. “Their 3D printing technology empowers us to quickly iterate and optimize components, ensuring that our staff has the best possible machines to stay ahead in this high-stakes environment.” 

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The R&D center had been using a Stratasys fused deposition modeling (FDM) machine and Stratasys is reinforcing that capacity with a second FDM printer. These produce the standardized NACA duct that NASCAR provides the teams for installation in the floor of the central driveshaft tunnel. They are made of ULTEM 9085 black material and introduce air into the tunnel to prevent heat from the rear-mounted transaxle from working its way forward and making the cabin floor too hot for the driver.

They are also adding a Stratasys NEO stereolithography (SL) machine to produce parts for aerodynamic testing and prototyping as well as for making high-precision tooling for production parts. Because of the high demand for parts from teams, NASCAR has outsourced printing the cockpit air intake vents to Stratasys Direct Manufacturing, where they’re made using an H350 SAF printer supplied with plant-based Nylon11 material.

“Our partnership with NASCAR allows Stratasys to showcase the unique advantages of 3D printing in motorsports,” said Rich Garrity, Chief Business Unit Officer at Stratasys. “From on-demand manufacturing of custom components to speeding up the design cycle, we’re helping NASCAR with faster production times and enhanced part performance.”

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A key advantage of the Stratasys machines, according to NASCAR design engineer Tim Murphy, is the mobile app that engineers can use to monitor the printing process. Printing large items can take many hours or even a couple of days and it is important to ensure that the printers haven’t run out of filament, or that if they’ve finished a job, that the part is removed so that it can start right away on the next part.

The smartphone app lets engineers monitor printers’ progress, so that rather than losing printer time by having it stop or wasting engineers’ time visiting the shop to check on progress during nights and weekends, they can just check each machine’s status using the Stratasys app, Murphy said. “Those are the little things that make a difference,” he said.

NASCAR outsources printing this windshield air duct to Stratasys Direct Manufacturing due to the high demand for parts from the race teams. STRATASYS

At Joe Gibbs Racing, they’ve been printing many parts for years, according to the team’s technical director, Matt Faulkner. The current NASCAR specification for its top-level Cup racing series mandates the use of mainly off-the-shelf parts purchased only from single specified suppliers to prevent costly development wars.

But teams are free to finesse some of the bodywork within certain parameters, and to do that, JGR prints many parts for wind tunnel testing, Faulkner reported. While it might seem like computational fluid dynamics modeling would provide the answers teams need to tweak their cars’ bodywork within the permitted parameters for maximum downforce and/or minimum drag, the models just aren’t good enough for that, he said.

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“We've done like a ton of work to get our model as perfect as possible and act as a guide to what to try in the wind tunnel,” said Faulkner. “What we found is that there's no replacement for actually trying all these versions in the wind tunnel.”

The teams try to sculpt body panels within the rules while also ensuring they retain some vague resemblance to the production model the race car purports to represent. But among the various parts that are open for customization, the hot air extraction vents in the hood proved to be the most productive.

Since the current Next Gen rules were first released in 2022, the cars take in air through the grille in the front and vent it through extraction ducts in the hood. JGR tested about 200 different variations of those vents, finding a shocking range of variability in the results. That’s because it quickly became apparent that the exiting air was steering airflow over the rest of the car.

Not only did testing these many variations reveal this surprise, but it also showed that with some hood louver designs, air exiting from under the hood was being routed to go into the open side window, making the driver hotter inside the car. “The interior of the car was actually cooler with the window shut than it was with the open because the air coming out of the right-side vent was blowing right inside the car,” Faulkner recalled.

The carbon fiber hood vent in a Joe Gibbs Racing hood, made in a design tested using 3D-printed parts that is optimized to steer air using the long slot at the bottom. DAN CARNEY

The only way to learn this was to test physical parts in the wind tunnel and the only way to rapidly produce the many iterations needed to learn about the airflow was to 3D print all of the louvers. The hood contains two louvered vents, one on the right side and one on the left side. Each of these is made from three 3D-printed sections from JGR’s Stratasys F370 printer that are glued together.

This was crucial, because “You could have a car that would be shaped the same except for the hood louvers and make big changes and move the needle just with the louvers itself,” he said.

Advances such as this are why NASCAR often sees a run of success by cars representing the same manufacturer, as all of these body parts are shared among the Chevrolet, Ford, and Toyota teams, he said.  When one brand finds an advantage, it takes a few races for the other brands’ teams to figure it out and catch up.

Left- and right-side mirror housings are also free to be customized and the team prints those models for testing. This led to the development of mirrors that are optimized for downforce and others that produce minimal drag, according to Faulkner.

The air plenum for the transaxle cooler is printed by Joe Gibbs Racing. DAN CARNEY

The ducting for cooling airflow to the Cup car’s rear-mounted transaxle is also open for innovation, so JGR experiments with variations using 3D-printed parts. At one point, NASCAR found that teams were hiding impermissible parts inside hoses in the cabin. They mandated clear material for those hoses to make visible anything that might have been hidden inside. JGR’s response was to print new hoses using clear material, solving the problem instantly. In total there are between 15 and 20 3D printed parts on the Cup car, he estimates.

NASCAR’s lower-level series have less restriction on the parts used, and the JGR Late Model racing teams employ brake ducts that they bolt directly onto the race cars as the parts come from the printers, he said.

Joe Gibbs Racing prints these brake duct vents, complete with their screens and installs them on the race cars. DAN CARNEY

Printing these parts lets the team keep testing and changing parts more quickly than would be possible otherwise. “Without our partnership with Stratasys and our ability to print things on five printers so fast, even over weekends into Sunday night, there's no way from, like a shipping and logistics standpoint, we can make that happen without the machines,” said Faulkner.