GM: LMDh Hybrid Deployment Methods “Still in Motion”

Photo: Mike Levitt/IMSA

The way LMDh cars will deploy its electric power in IMSA WeatherTech SportsCar Championship races is still being defined according to GM sports car racing program manager Laura Wontrop Klauser, who indicated that specific regulations for the so-called “equity model” are in the process of being finalized.

All four debuting LMDh manufacturers that will compete in the GTP class next year will utilize the same 50kW (67 horsepower) Bosch electric motor combined with the Williams Advanced Engineering-supplied battery and Xtrac gearbox.

With an official update to the joint ACO-IMSA LMDh technical regulations not having been published publicly since June, manufacturers such as Cadillac have been going through the paces with its V-LMDh car evaluating different deployment strategies that could be used in the series next year.

Sportscar365 understands that a decision on whether cars will be required to run on full electric mode while in pit lane was yet to be decided as of last month, with other key points still awaiting final confirmation from the sanctioning bodies.

“We’re working on the simulation side and understanding and figuring out across the class what’s the plan,” Klauser told reporters during an IMSA-hosted Zoom session last week. “Some of that is still in motion. It’s probably the most exciting part – all of the opportunities.

“We can drive the car in electric mode. We can launch it, so you can see the true hybrid coming out.

“Where we evolve and how that works from the fuel economy standpoint versus other usefulness of having an electric motor on the car is what is going to make the class interesting.

“How each OE approaches that and how we change our strategy as we learn more.”

Klauser said the hybrid deployment rules are being defined inside the equity model that each manufacturer must adhere to.

“That defines a lot of parameters on how we can use it and basically where and when,” she explained.

“I think there is a little freedom in how we’re integrating everything and when we want to use the power coming off the hybrid versus engine power, or both or mix that.

“That’s where a lot of the learning is happening and working through things well past January because there is a lot to look at.

“There is some opportunity to have some identity from each OE’s perspective, but they’ve done a lot of work to make sure that they keep it parity as much as they can so that we don’t end up in a situation where one car is completely off in the weeds either positively or negatively and the rest are not.

“It’s evolving and we’re excited to find out all the things we can do.”

With LMDh cars in the midst of its homologation process, which included a recent test at Daytona International Speedway for further aero and performance validations, Klauser said she feels Cadillac is in a good place in meeting the requirements.

The manufacturer has completed more than 11,000 kms in testing so far, ahead of a planned 24-hour endurance test potentially later this month.

“From an aero perspective, I wouldn’t say it was too different for the hybrid,” she said. “We did a lot of work in wind tunnels getting ready.

“The window that they’ve given us for the aero map that we have to fit in is quite small compared to things we’ve done in the past. And I think important because that’s what is going to help get the cars close to each other despite the fact that each one looks so different from each other.

“That’s good in terms of getting them set up for good racing. Starting with the scale wind tunnel – and a lot of that came from creating the body shape – we would check our ideas and still putting the car where it needs to be.

“When we had our first real full-scale race car, we started doing work in the big wind tunnels. The hybrid is weight to the car, so we need to keep on eye on that as we look at performance. But with that map being so small, our No. 1 target is getting there and the rest falls into place.”

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