Doonan: LMDh Ruleset Key to Early Season GTP Parity

Photo: Jake Galstad/IMSA

IMSA President John Doonan has credited the LMDh ruleset for having produced parity in the first half of the WeatherTech SportsCar Championship GTP season that’s even surprised the sanctioning body.

All four LMDh manufacturers claimed victories in the first five rounds of the new GTP era, capped off by BMW’s win in last month’s Sahlen’s Six Hours of The Glen.

As a result, BMW M Team RLL became the fifth team to win in as many races, following victories by Meyer Shank Racing (Acura), Action Express Racing (Cadillac), Porsche Penske Motorsport and Chip Ganassi Racing (Cadillac).

MSR became the first repeat winner in last weekend’s Chevrolet Grand Prix at Canadian Tire Motorsport Park.

“You have hopes of that but I don’t think we ever envisioned, especially with some of the concerns about reliability and things like that early on,” Doonan told Sportscar365.

“We never imagined that we’d be at this place.

“I was thinking about it after Watkins, once BMW was officially announced as the winner, and how did we get to this point.

“I think it starts with the ruleset. The work that Simon [Hodgson], Matt [Kurdock], Bill Pearson and Thierry [Bouvet] all all these guys did to get us to this point with a pretty tight ruleset.”

It has contrasted the start of the DPi era in 2017, which saw a seven-race win streak by Cadillac, including five consecutive victories by Wayne Taylor Racing.

While forming the same fundamental foundation, the LMDh regulations have been built around a considerably tighter performance window, in association with the ACO.

“The ruleset is tight because that’s what DPi stood for. But it’s also what the manufacturers encouraged us to do to save them from themselves,” Doonan said.

“You’ve seen it also when it comes to GTP in the BoP. The changes have been ‘adjustments’ as opposed to major swings.

“The manufacturers appreciate that and that also is a testament to the rules because you started with a ruleset that maybe put you in a position for that right at the outset.

“It’s very encouraging and I’m happy for our sport.

“For all of those manufacturers to have made the investment that they’ve made to be here and also have experienced a victory in the first half of the season is incredible.”

Unlike previous seasons in DPi, which saw considerable changes between races, the GTP Balance of Performance has remained stable through the first half of the season, with only minor adjustments in minimum weight, power and energy.

While Doonan admitted work is still to be done in the GT classes, he said he’s been proud of what the IMSA technical team has been able to establish for the top class.

“I say this with a smile, I wish BoP was never a topic,” he said. “It’s a beautiful part of our sport of endurance sports car racing, the variety we have.

“Normally aspirated, turbo, front engine, rear engine, you name it… But it’s a challenging part of what we do.

“It’s a blessing on one hand and it’s a challenge on the other.

“I’m proud of it on GTP. We continue to work at it, especially in GT with new cars and understanding the performance characteristics of those cars and making sure that everybody is always in the hunt.

“That would be our goal. Every weekend it’s about making sure everybody has a fair shot.”

John Dagys

John Dagys is the founder and Editor-in-Chief of Sportscar365. Dagys spent eight years as a motorsports correspondent for FOXSports.com and SPEED Channel and has contributed to numerous other motorsports publications worldwide. Contact John