The rain-delayed, then shortened IMSA MICHELIN Pilot Challenge race at Road America packed more “can you believe it?!?” type content into 75 minutes than most full-length IMSA races.

What occurred over the 75 minutes made for one of the craziest and most exciting races of the season.

The final lap charge from Robin Liddell capped it all off in style.

“The races at Road America were fabulous, especially the MICHELIN Pilot Challenge race,” said Ken Payne, technical director, motorsport, Michelin North America.

“You look at the mix of strategies employed, some on wets, some on slicks at the start. Then when do you switch to slicks if you switch to slicks? Do you do it in one stop? Two stops? Three stops?

“And it came down to a one-lap flyer with an amazing pass of two cars on the outside, then two wheels on the grass on the front straight to get the win.”

Here’s how it got there. If you want to watch the full race replay with IMSA Radio commentary, it’s linked below.

PRE-RACE, WITH WEATHER DELAY AND OPPORTUNITY TO SWITCH

The race was scheduled to start at 4:05 p.m. CDT and local time. Of course, the key words there are “was scheduled.”

First light rain, then heavy rain, along with hail and lightning postponed the start until after 5 p.m.

Once a break occurred in the weather, IMSA determined the race would go ahead with a reduction from the standard-length two-hour distance to the adjusted 75-minute amount. This ensured teams would have to make at least one stop. IMSA also adjusted the minimum drive time to 25 minutes.

IMSA also allowed teams to switch from their qualifying tires, which were the MICHELIN® Pilot® Sport GT S9M (hard) commercial tires, onto the MICHELIN® Pilot® Sport GT Rain tires.

Not every team did, and a smattering of GS and TCR competitors opted to start on slicks.

What followed next was a somewhat surreal series of events as the race got underway.

A WET DICE UP FRONT, AND AN INTENSE CHARGE FROM THE SLICK RUNNERS

Two fascinating strategies played out once the race got underway, as Michelin North America motorsports marketing manager Sarah Robinson waved the green flag.

The rain had stopped, but the track was still wet. A first question was whether those on the wets could hang on long enough into their fuel stint to get in the window to make it on one stop and not lose too much time. A second was whether the slick runners could navigate the opening laps cleanly, then charge forward.

Both played out nearly as anticipated as the first stint moved on and the track began to dry.

Two drivers, Jesse Lazare in the No. 69 MIA McLaren 570S GT4 and Tyler McQuarrie in the No. 39 CarBahn by Peregrine Racing Audi R8 LMS GT4, stole the spotlight as the stint progressed. These are two of the top three cars in the GS championship, and proceeded to charge forward after falling back on the start.

McQuarrie started from pole, Lazare from fifth, and they fell to 11th and 12th by Lap 2. However by Lap 9, running anywhere from five to six seconds per lap quicker on the slicks, Lazare was up to third and McQuarrie up to fourth.

They were closing on the leading pair of Kenton Koch in the No. 2 eEuroparts.com ROWE Racing Audi and Akhil Rabindra in the No. 09 Automatic Racing Aston Martin AMR Vantage.

Running the wets to a later stage in the race than they may have anticipated, what followed was a great dice by both drivers.

Koch has raced in mixed conditions throughout his junior sports car career, notably winning a Battery Tender MX-5 Cup race overall when in a secondary class (at Mid-Ohio). Rabindra, an Aston Martin Racing Academy driver in Europe, was making his MICHELIN Pilot Challenge series debut and thrived in the conditions.

KOCH, MCQUARRIE ON THEIR POLAR OPPOSITE STRATEGIES

“I wasn’t aware of who he was, but he did a great job to race me clean and hard,” Koch said of the battle with Rabindra. “I had the brakes on him, but their car had the straight line speed once he cleared me.

“Once it dried out, I didn’t know what the weather looked like. But the team made the great call to hang on to the wets, push our (fuel) window as late as possible and put another set of wets on. It worked out perfectly! My in lap (Lap 17), the fuel light came on.

“It was such a blast, where it felt like driving on street tires, sliding around all the time, and I bet it was entertaining to watch. We’d done a ‘rain dance’ going into the race because I love driving in these conditions, and I’ve had a knack for enjoying it and sliding the car around.”

Koch also noted the track dried fairly quickly, but due to much cooler ambient and track temperatures, it didn’t dry as fast as in similar conditions at Watkins Glen. There are different asphalt patches at Turns 5, 6, 8 and 14, so that dried differently than the older asphalt at the historic track.

McQuarrie, meanwhile, recapped his stint behind the wheel where he had the opposite move: falling back to start, then ascending forward as the track dried.

“My stint was crazy,” McQuarrie said. “I was one of only two cars to roll on slicks and for the first few laps, it was hard to tell what the right choice was. I just kept thinking I had to protect the car, keep it on the black and whatever happens, happens. I got freight trained at the start, I’m not even sure where we fell back to.

“The rain stopped about 20-minutes into the race and the track started to dry up. I actually was the fastest car on track by that point. At the end starting on slicks was the right call. It was just crazy conditions and you never know what’s going to happen. The team did a great job adapting to everything and overall I think we had a really great weekend.”

A SCRAMBLE BACK TO WETS

Once teams made the call to pit, there was just enough of a window to make hay on another set of slicks. But before too long, it started raining again, and there was a scramble back to wets.

Continuing the theme of mixed strategies, some teams opted to return to their starting set of wets, or go to a new set of wets. The Michelin Radio Frequency ID (RFID) reader at pit out tracks each car’s dry weather set of tires, so it was busy monitoring which cars were going back to slicks.

Once the rain hit though, it was time to switch back to wets. Times fell by about 10 to 12 seconds from the slick times to the wet times.

Two full-course cautions then jumbled the field. An incident for the No. 80 Bimmerworld BMW M4 GT4 brought out the first yellow on Lap 20, and an off for the Rabindra/Kris Wilson No. 09 car caused the second of the cautions when it stopped on course on Lap 24.

A ONE-LAP DASH TO THE CHECKERED FLAG

The final lap came with the field now on wets. The GS lead changed hands twice. TCR’s lead changed hands after the checkered flag fell.

First, Kuno Wittmer in his No. 75 Compass Racing McLaren passed Corey Fergus in the No. 69 MIA McLaren at Turn 3. It appeared Fergus would hold on to at least second, with Eric Foss close but not able to get past behind him, in his No. 56 Murillo Racing Mercedes-AMG GT4.

They hadn’t accounted for Robin Liddell in the No. 71 Rebel Rock Racing Chevrolet Camaro GT4.R. With a cursory look at timing & scoring at that first caution, it’s doubtful anyone had.

On Lap 21 under yellow, Liddell was 21st overall. Once the reordering process moved the GS cars ahead of the TCR cars, that promoted Liddell up to 14th. Even so, it was hard to forecast him as a potential winner until the first restart where he passed 10 cars in one lap to ascend to fourth place.

That put him fourth behind Fergus, Wittmer and Foss for the one-lap dash. His move around the outside of Foss and Fergus at Canada Corner followed, with the pass of Wittmer up the hill coming only after Wittmer accidentally hit the pit lane speed limiter instead of the radio to call his team.

Miraculous as Liddell’s charge was, Wittmer’s Compass team comeback was potentially even more so. Some team members had stayed up 34 hours consecutively to change the engine. The car started from the back of the field, and nearly completed a last-to-first race.

Foss, too, hailed co-driver Jeff Mosing who’d driven a strong opening stint in the mixed conditions.

“The Michelin wet tires were really, really good,” Foss said. “Jeff drove for a long time in drying conditions. He had a stellar stint and went from 18th to fifth at one point. The fact that he brings me in here and lets me be a part of this team and this program is really a blessing for me.”

TCR saw Bryan Herta Autosport’s Mason Filippi and Harry Gottsacker inherit the victory after HART got sent to the rear for a drive time infraction. Having only missed the minimum by several seconds, HART was left to rue the missed opportunity. Herta’s pair though played it well with starting on slicks, and then switching to wets.

BY THE NUMBERS

Per IMSA’s timing & scoring data, these are some of the notes from this race:

• Eight cars started on slick tires, and they were largely able to stretch their first stints the longest as the track dried.
• A total of 11 cars made one pit stop, 20 cars made two pit stops, and two cars made three pit stops.
• The winning No. 71 Camaro was scored in 12 different positions overall in the 27-lap race (first, fourth, 14th, 15th, 17th, 18th, 19th, 20th, 21st, 22nd, 23rd, 24th).
• Fergus slipped to a hard-luck seventh after losing out up the hill following his battle with Foss on the final lap.
• Koch and Tyler Cooke ultimately finished a season-best sixth, after losing out to Trent Hindman on the final lap for fifth.
• In TCR, Jon Morley rose from seventh to fourth on the final lap in the Roadshagger Audi. That became third after the HART car’s penalty assessment.
• Michael Lewis rose from ninth to fifth on the last lap in his Herta Hyundai, in a move that may prove important for the TCR title later this year.
• Official Results