OPINION: How IMSA’s DPi era made sports car racing better

Michael Levitt/Motorsport Images

OPINION: How IMSA’s DPi era made sports car racing better

Insights & Analysis

OPINION: How IMSA’s DPi era made sports car racing better


Find a picture of a first-generation Daytona Prototype, circa 2003-07, from what was then called the Grand Am Rolex Sports Car Series. Now put it alongside a picture of a current IMSA WeatherTech SportsCar Championship Daytona Prototype international (DPi) competitor — or even better, one of next year’s LMDh prototypes out testing for what promises to be a banner 2023 season for sports car racing around the world.

The briefest glimpse of those side-by-side images quickly illustrates just how far top-level sports car racing in America has advanced in the last 20 years. It’s an amazing transformation, one that has not only produced exciting, attractive, modern racing cars, but also a radical shift in philosophy about IMSA’s place in the world sports car hierarchy.

Jan Magnussen’s Pontiac Riley ahead of Memo Rojas’ Lexus Riley from 2007 exemplify the first-generation Daytona Prototypes. Denis Tanney / Motorsports Images

Those early DPs were jarring — crude, technically simplistic tube-frame chassis with pushrod V8 engines that sounded more NASCAR than sports car. With a comically large greenhouse (safety first, it was said), early DPs looked like a child’s scrawled rendition of a Porsche 956.

The Grand Am mindset was also jarring, especially because American sports car racing was in the midst of a “split” between Grand Am and the American Le Mans Series that had the potential to be every bit as damaging as the schism in IndyCar racing between CART/Champ Car and the Indy Racing League. It was easy to draw parallels between Grand Am and IRL, both of which tried to cut costs by mandating low-tech, budget-minded cars that were an insult to the sophisticated and graceful machines that preceded them.

But that mindset gradually changed over the years. Daytona Prototypes got marginally more attractive, with new generations rolled out in 2008 and ’12. Grand Am absorbed ALMS at the end of the 2013 season, coming together under the WeatherTech SportsCar Championship banner; and after three years with third-gen DPs serving as the top class, the DPi formula that debuted in 2017 not only restored a much higher level of technology to American sports car racing, it significantly enhanced IMSA’s credibility with the FIA and the World Endurance Championship.

It cannot be overstated how important DPi has been for IMSA’s growth and future momentum. By pairing homologated LMP2 chassis with engines and unique bodywork affiliated with OEM manufacturers, IMSA created a formula that produced safe, attractive, and (comparatively) cost-effective cars.

DPi offered great diversity, with four-, six-, and eight-cylinder competitors, and the on-track product was close and competitive, thanks to effective use of the Balance of Performance philosophy that is now common in sports cars and other major forms of motorsport — most notably NASCAR.

Certainly, plenty of folks bemoaned the “NASCAR-ification” of sports car racing when the Grand Am came onto the scene. After all, Jim France is credited as the series founder, and it operates under the NASCAR umbrella.

Turns out that wasn’t necessarily a bad thing. Following the American sports car merger, NASCAR’s ownership provided financial and organizational stability for the combined WeatherTech Championship, and the creation of the DPi formula appeased fans and manufacturers who pined for the more advanced factory-supported prototypes from the ALMS era.

DPi’s six-year run resulted in three championships apiece for Cadillac and Acura, along with race-winning programs from Nissan and Mazda. It also coincided with a concentrated effort between IMSA, the FIA, and the ACO to work together in a more harmonious fashion to unify and strengthen sports car racing on a worldwide basis.

The DPi era brought a variety of more graceful, factory-supported sports prototype machinery back to North America.  Michael Levitt / Motorsport Images

With that in mind, when IMSA began planning the next generation of its top-class prototype to replace DPi, it was done with the intention of finding a way for its manufacturers and teams to take those cars to the 24 Hours of Le Mans and other FIA World Endurance Championship races and compete for overall victory. Equally importantly, that crossover would work both ways, equalizing cars built to FIA “Hypercar” specification to compete with the new IMSA cars through a jointly developed common gearbox and hybrid system.

That’s what sports car fans will have to look forward to in the future: IMSA’s revived GTP category makes eligible its homegrown LMDh prototypes from Cadillac, Porsche, Acura, BMW, and (joining in 2024) Lamborghini, along with WEC Hypercars from Toyota, Peugeot, and Ferrari. The first major convergence will come at Le Mans, where the 100th anniversary of the first 24 Hours will be celebrated.

Getting back to where we started, place a picture of a 2023 IMSA LMDh next to the image of a WEC Hypercar, and they both look sleek, modern, and exciting, packed with current, relevant, state-of-the-art technology hidden under the skin. The visual comparison to a boxy 2003 Grand Am Daytona Prototype is mind boggling.

Cadillac’s V-LMDh is part of the next generation of IMSA that builds on the framework created by DPi cars. Photo courtesy of Cadillac Racing.

It’s another way of visually demonstrating just how far IMSA has come — not only in terms of how it embraces much more of a world view in terms of the relationship between technology and sports car racing, but also in the way that American sports car racing commands much more respect on an international level than it has at any time in the past.

The DPis will race one more time next weekend in the 25th annual Motul Petit Le Mans at Michelin Raceway Road Atlanta. They will no doubt put on a great show, but for IMSA — and for sports car racing fans around the world — the best is yet to come.

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