Michelin IMSA Insider: Opportunity Knocks at Lime Rock

This week’s Northeast Grand Prix at Lime Rock Park presents several rare opportunities for the Michelin Pilot Challenge and IMSA WeatherTech Championship teams.

The first of two GT only events, the 2 hour 40-minute WeatherTech Championship race on the 1.5-mile circuit guarantees a GT overall race winner.

It also presents the best opportunity for a GTD entry to claim a podium spot or, given the right circumstances, perhaps an overall race win.

The IMSA class structure is designed to provide a stratification ranging from the DPi class through the three prototype classes, GTLM and GTD class.

To help establish and maintain separation between the GT classes, IMSA permits the GTLM cars to use their highly confidential Michelin soft, medium, and hard compound slick tires developed for each respective chassis.

The GTLM teams may also mix and match their fitments.

At Lime Rock Park, that may mean a softer compound tire on the lightly loaded right front wheel position. But, with just three GTLM entries, the 14-car GTD field will be poised to take full advantage of any miscues.

Both classes run the same commercially available Michelin Pilot GT treaded tires. In the event of wet conditions, the GTD teams can take advantage of their ABS systems, which are not permitted in GTLM.

The 2019 Lime Rock race saw the winning CGR Ford GT rack up a stunning 182 laps or 268 miles in the 160 minutes of competition.

Not far behind, the Pfaff Motorsports Porsche led the GTD field having completed 178 laps. The GTLM lap times were in the high 50 to 51 second range while the GTDs were in the low-to-mid 52 second bracket.

Pilot Challenge GS v. TCR

There is a similar story of stratification and opportunity in the Michelin Pilot Challenge, where the circuit, the shortest of the IMSA season, provides real opportunities for a TCR entry to claim an unprecedented podium or overall race win.

When the IMSA teams last ventured to the Connecticut circuit in 2019, the Hyundai Veloster N TCR of Bryan Herta Autosport w/Curb-Agajanian stunned the paddock by setting the second fastest overall qualifying time with a time of 54.034 seconds.

The 300-350 horsepower, front wheel drive TCR cars make their lap times much differently than their bigger, 400-450 horsepower rear wheel drive GS brethren.

“We run very similar lap times, within 1 second. We make up this time under braking, cornering, and handling. Lime Rock is a good track for us because there is very little straightaway,” said Kyle Compton, engineer of the points leading No. 77 Hyundai Veloster N TCR. 

The race in 2019 saw only one caution period lasting around nine minutes.

That lack of yellow flags helps the TCR’s avoid being put behind the GS cars on restarts. It can also be important if they can stretch fuel mileage and finish the two-hour race on a single pit stop.