HRC USA president David Salters, who is responsible for the ARX-06 program, told Motorsport.com at the season-opening IndyCar Series round at St. Petersburg last weekend that the reduction of 17kg since the Rolex 24 Hours at Daytona should give it a better fighting chance on raw pace at Sebring this weekend.
The Wayne Taylor Racing with Andretti Acura driven by Louis Deletraz, Jordan Taylor, Colton Herta and Jenson Button finished a distant third at Daytona. Its cars could only qualify fifth and sixth in the 10-car GTP field, Acura having swept to pole position and won there in 2023 with Meyer Shank Racing.
Last season, Acura was right in the title fight with Cadillac in the final round at Petit Le Mans – and only lost out following a late-race clash between its star driver Filipe Albuquerque and Caddy’s Pipo Derani, the latter going on to win the title with Alexander Sims.
Since then, the Acura was slapped with significant extra ballast on IMSA’s BoP calculations, which have changed in ethos for this season to be reactive to recent races and past events at each track.
“We have a very heavy car,” Salters told Motorsport.com at Daytona, who was at pains to point out he wasn’t complaining about the BoP. “I took [the weight penalty] as a compliment! We’ve done such a good job, so it’s a great compliment to our boys and girls.
“Heavy cars are not the kindest things on their tires. Physics is physics, and weight affects all aspects of the car: tires, braking, turning and accelerating.”
When asked why he thought Acura’s BoP for the Rolex 24 was so drastic in terms of the weight gained, Salters replied: “It’s plainly a question best asked to IMSA. It’s simulation-based.
“They are trying to get all the cars to be equal and I guess, in terms of knowing what the aero is and knowing they can balance that with power and weight, they do their simulation.”
But IMSA has now reacted to its real-world findings from Daytona, with the pace-setting Cadillac hit by a 30kg increase, which means it will be 22kgs heavier than when it won at Sebring last year at 1060kg.
In comparison, the Acura will run at 1055kg, but Caddy’s V-Series.R has also been given a 10kW power increase to compensate.
In another twist, the Daytona-winning Porsche 963 has been trimmed of 2kg to 1049kg, but been given a 11kW power reduction. As well as its weight reduction, which still makes it the second-heaviest car in the field 5kg behind the Cadillac, the Acura has had its power output stemmed by 8kW.
Intriguingly, Lamborghini’s new SC63 LMDh entry, which makes its IMSA SportsCar debut in the GTP class, will be the second-lightest entry at 1044kg – 14kg heavier than the BMW M Hybrid V8.
The Iron Lynx-run car will also be the third-most powerful car on the grid, behind the Cadillac and BMW.
IMSA GTP Balance of Performance (weight v power)
|
Acura ARX-06 |
1055kg |
512kW |
|
BMW M Hybrid V8 |
1030kg |
506kW |
|
Cadillac V-Series.R |
1060kg |
520kW |
|
Lamborghini SC63 |
1044kg |
513kW |
|
Porsche 963 |
1049kg |
508kW |
