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Michelin IMSA Insider: The Highs and Lows of Road America

Road America to present teams with “highs” and lows” this weekend…

Photo: Michelin

Road America, site of this week’s IMSA Road Race Showcase, is a measure of extremes between highs and lows.

The highs and lows touch elevation, fuel consumption and tire wear.

These highs and lows combine to make for extreme emotions at a track that’s a driver, team and fan favorite.

Highs and Lows for Back-to-Back Tracks

Lime Rock Park and Road America, as back-to-back venues on the IMSA calendar, offer significant juxtaposition.

Lime Rock has the shortest track length (1.474 miles) and lap time (sub-50 seconds for GTLM) of the year. Road America, naturally, is the longest in length (4.048 miles) and time (more than 2 minutes for GTLM).

Stint lengths by lap count at Lime Rock can exceed 60 laps. At Road America, they’re in the mid-20s.

Last race at Lime Rock, the GTLM winner ran a three-stop race to beat the two-stoppers. The IMSA Michelin Pilot Challenge GS winner, however, ran a one-stop race.

At Road America, the DPi and overall winner will need three stops to win. But, don’t be surprised if the GT class winners can make it in only two stops.

Photo: Michelin

Don’t Get Trapped at the Low Track Points

With some 176 feet of elevation change from the crest at Turn 1 to Turn 12 (Canada Corner), Road America’s consistent rising and falling is part of the track’s heritage and story.

Three of the lowest points at Road America’s fast, flowing and long permanent road course are Turn 5, Turn 12 and Turn 14, the final corner before pit in.
These low points can offer heartbreak if you emerge at the wrong side of these turns.

Turn 5 is renowned as one of the best passing spots at the track. The downhill run has an inviting inside line for drivers to make a charge, and then track out wide towards the exit. The same is true at Turn 12, Canada Corner, which is flatter on entry as cars exit the Carousel, power through the Kink and line up for the right-hander.

If a car leaves too much room on the inside, they often get bit and run over the massive rumble strips and into the gravel and grass before resuming up the hill into Turn 6, under the Chevrolet bridge and also before the slight run up the hill through Turn 13.

At the low point of Turn 14, exiting the corner, a team’s race could be over in an instant without enough fuel momentum to make it up the hill.

There are countless examples of teams and drivers running out of fuel and being stranded on the steep uphill run to the pits.

Photo: IMSA

But Do Cool Your Tires on the Long Straights

Three long straights at Road America provide high speeds, and a break for the Michelin tires to cool off – relatively speaking – at an aging surface and a fairly abrasive race track.

“Road America still works the tires pretty hard. But Road America has more straightaway length than some other circuits,” explains Ken Payne, technical director, motorsport, Michelin North America.

“Tires naturally reject a lot of energy, or heat. At a track like Watkins Glen, you don’t have as much straightaway distance to reject that heat. There, you would get more of an accumulation of energy going to and remaining in the tires.”

For GT Le Mans teams, which have three options of their Michelin proprietary tires to choose from, Road America’s long straights have helped increase tire performance in the past. Porsche’s performance in 2015 stands out, as Payne recalled.

“Going back a few years ago, when we had some new special tires, we were super quick out of the box and broke a bunch of records,” Payne recalls. “One of the things that allowed us to successfully use that tire at that track was the long straightaways. You could really get rid of the heat between the high load, high speed corners.”

Speeds are fairly high at Road America. The top trap speed for DPi cars here last year was 182.702 mph, the top speed in GTLM was 170.573 and the top speed in GTD was 164.762.

Top speeds on the straights are one thing. But the track is also known for its range of third-to-fourth gear, high speed corners.

The balancing act between the high speeds, high loads and long straights makes for quite a dance for the tires at this circuit.

Photo: Michelin

Save Enough Fuel so your Race Ends with a High, Not a Low

In the IMSA WeatherTech SportsCar Championship race here, fuel consumption is a story that determines the outcome in a big way.

Last year’s overall race winners CORE autosport, then in an LMP2-spec ORECA 07, made it 25 laps (more than 100 miles) and 56 minutes on their final stint to take the checkered flag, with seven of those laps under caution. Meanwhile the No. 55 Mazda RT24-P needed a final splash with just under four minutes to go.

The lead also changed hands in GT Le Mans. Connor De Phillippi sought to make it home in the BMW M8 GTE he shared with Alexander Sims, but ran out of fuel and limped up the hill. They dropped to sixth place.

The first and second place cars in GTLM from Ford Chip Ganassi Racing and Corvette Racing each made it one hour and three minutes, and 26 laps apiece, on their final stint of the race.

In the supporting Challenge race, GS class winner Trent Hindman was able to go even further, more than one hour and five minutes, to stretch his fuel load in the VOLT Racing Ford Mustang GT4 he shared with Alan Brynjolfsson.

Hindman, this year’s GTD class points leader with Meyer Shank Racing’s Acura program, is in a unique position from a strategy standpoint. He works with Mike Johnson with Park Place Motorsports in the IMSA Michelin Pilot Challenge, but competes against Johnson and Park Place in WeatherTech Championship racing.

Because of all these elements, the euphoric highs and crushing lows often coalesce in Road America’s victory lane.

The winners deal with drops of champagne on their firesuits. And oftentimes, the runners-up regret the drops of fuel that kept them away from the top step of the podium.

Photo: IMSA

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