PRUETT: Roar reflections

Image by Levitt/LAT

PRUETT: Roar reflections

IMSA

PRUETT: Roar reflections

What did we learn at IMSA’s WeatherTech SportsCar Championship Roar Before The 24 test?

Speed is back. The paddock loves its new Michelin tires. Mazda mastered the art of chess-boxing, and there’s so much more to cover — let’s start with the first two items, which are linked.

The 2019 edition of the event will be remembered as the ‘We Love Our Michelins’ test.

Using a basic comparison of fastest Roar ‘qualifying’ lap times from 2018 on the spec Continental tires and what teams just produced on Michelin’s products, the extra grip available through the corners has brought plenty of smiles to the paddock.

Image by Levitt/LAT

Time navigating the infield was down, and at Daytona, where drivers spend the majority of each lap at full throttle on long and winding straights, the improved traction offered by the Michelins also meant their machines left the corners harder, which translated into shorter elapsed times on those straights.

In DPi, Mazda Team Joest’s Oliver Jarvis managed something few would have expected from an LMP2-based car by eclipsing the 26-year-old Daytona lap record set by All American Racers and its greatest-of-all-time GTP model, the Toyota-powered Mk III.

The Briton’s lap of 1m33.398s, nearly a half-second below P.J. Jones’ pole of 1m33.875s from the 24-hour race in 1993, was not a new official standard due to being generated at a test, but it demonstrated the year-to-year leap made by IMSA’s DPis. The best from last year’s Roar time trials was a 1m35.806s — or 2.408s slower — delivered by an Action Express Racing Cadillac DPi-V.R.

IMSA has given the DPi class a slight bump in BoP to create proper separation to the prototypes in its new LMP2 class, but overall, the big leap in speed is directly related to the big increase in tire performance.

Image by Dole/LAT

“The BoP freedom has definitely had an effect, especially at a track like Daytona where straight line speed and power has such a big influence, however, the majority of the lap time improvement definitely comes from the Michelin tires,” Jarvis told RACER. “They have been a big step in overall grip from the Continentals. I would say it’s at least two seconds, purely from the tires.”

A similar improvement was found in LMP2 where, despite IMSA taking power and optimal gearing away from the spec prototypes to create the aforementioned gap to DPis, the No. 52 PR1/Mathiasen ORECA 07-Gibson team went 1.344s faster than the top P2 lap of 2018.

GT Le Mans, the only class to use Michelins prior to 2019, also found pace with a different tire solution brought by the French manufacturer as Corvette Racing’s C7.R managed to gain 0.959s from the best Ford Chip Ganassi Racing’s GT recorded 12 months ago.

To fully appreciate the speed at which the GTLM cars are traveling at Daytona, Corvette’s Jan Magnussen crossed the start/finish line with a 1m42.651s lap to top all competitors in the class. Wind the clock back to 2015 with the actual pole for the Rolex 24 achieved by Michael Shank Racing’s Ligier JS P2-Honda LMP2 entry of 1m39.194s on Continentals, and the rate of progress is stunning.

Image by Galstad/LAT

In round numbers, that’s a 3.5-second separation from 2015’s fastest prototype to today’s top GT car. Leaving the Roar, the number is up to 9.25 seconds between Jarvis’ Mazda and Magnussen’s Corvette. Coming back to the central theme, the Michelins account for the huge change, along with the overall gains in performance and technology contained within IMSA’s DPi platform.

And in GT Daytona, the leap was 1.837s as 2018’s best of 1m47.374s by the GRT Grasser Racing Team Lamborghini Huracan GT3 was upgraded to a 1m45.537s from Meyer Shank Racing’s Acura NSX GT3.

“It’s wise to look at the only change we’ve had year-to-year,” Jeff Westphal said of the Michelins on the Ferrari 488 GT3 he drives for Scuderia Corsa. “All the GTD cars have been refined during the offseason, but I’d put 1.5 seconds of it down to the tires. When I give throttle input and we’re rolling through the center of the corners, the Michelins give more of what we ask.”

Averaged across the four classes, IMSA’s fastest cars from the Roar bettered 2018’s top laps by 1.637s. We can’t attribute all of it to a change in tire partners, but it’s also fair to say that without the move to Michelin, lap-record speeds wouldn’t be the big headline to follow when proper qualifying gets under way at the Rolex 24.

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