The release of IMSA’s Balance of Performance tables for the Rolex 24 At Daytona is imminent, and one area of interest to monitor involves the pace of its four WeatherTech SportsCar Championship classes.
With the addition of a new class in LMP2, the move to Michelin as its new tire supplier, and a general recalibration of its BoPs for DPi, GT Le Mans, and GT Daytona, IMSA used its recent Roar Before The 24 test to evaluate the separation in lap times and top speeds across the four categories.
One line of thinking, which emerged during the Roar, positioned GTD as the one class that could warrant a slight reduction in pace, but according to IMSA competition VP Simon Hodgson, it might not be necessary.
“From the initial data that I’ve been provided by our engineering staff, we’ve got a reasonable class separation between DPi and LP2,” he told RACER shortly after the Roar’s conclusion. “Obviously, there’s a much larger separation down to GTLM, and in between GTLM and GTD. Approximately two and a half percent separation. Top speed, that’s always another major thing to monitor. First of all, IMSA was charged really with doing BoP for the lap time and then it became, ‘Well, now we want really more balance with not only lap time, but top speed.’
“We have many parts of to manage with BoP in each class, as you know, and with GTD, the problem is if we were to pull back GTD further, there’s some manufacturers of cars that were already carrying an awful lot of mass. And it’s not always as easy just taking more power out. We want to ensure that these GTD cars also perform in the same way to what these folks drive elsewhere around the world.”
The other option to create more separation between IMSA’s GT classes would involve manipulating GTLM.
“You could say, ‘OK, well let’s push GTLM up. There’s lots of head room for more speed,’” Hodgson continued. “Well, that isn’t the universal agreement that we’ve made with all of the manufacturers. To do so at this point, again, would be entering another unknown area. Right from the get-go we talked and engaged with Michelin. They were pretty confident. They felt we weren’t going to get a big surprise here at this event. We don’t believe we did. But, fastest lap time there was 1m42.6s for GTLM compared to 1m45.9s for GTD. I think we’ve charted our course that we’re on.”
Hodgson and his competition staff held its familiar post-event conference calls with the manufacturers represented in each class. Those brands have weighed in on whether they believe their cars — or those of a rival — should be subject to BoP changes, and IMSA has filtered through its data from the Roar to determine where the adjustments will take place.
Final word on class performance separation and tweaks to the competitive capabilities of the cars in those classes will make for plenty of talking points once they are revealed.
“Normally we would do all that work, we’d have a discussion with the manufacturers toward the end of the process, and then we’d put the BoP out,” Hodgson explained. “This time, we’re following on through more of our work in the off-season where we’ve been engaging with them. And we’ll have that conversation much sooner so that if there’s any question about the inputs that IMSA should be using or we don’t really think that’s relevant. Let’s do that in the front end so that when we do come out with the BoP, everybody understands what we worked through to get to that point.”