You are here: Home » International » News » Technology
Business Standard

How Koenigsegg broke the land speed record with its Agera RS

Tires. Downforce. Weight. Horsepower. Aerodynamics. When you're going 277 miles per hour in a production car, everything matters

Hannah Elliott | Bloomberg 

Photo: Reuters
Photo: Reuters

This month a hit the highest ever for a production vehicle.

Driver Niklas Lilja averaged a top of 277.87 mph across two runs in the $2-million coupe on a 11-mile, closed-off stretch of Highway 160 near Pahrump, Nevada. 
 
That beat the previous record of 267.8 mph set by a Super Sports model seven years ago in Germany. It also beat the Hennessey Venom GT and McLaren F1 that had previously owned or approximated similar top speeds.  

What’s more, Lilja set records for highest in a single direction on a public road (284.55 mph); a zero-400-zero km/h run (33.29 seconds); the highest average for a mile with a flying start on a public road (276.36 mph); and the highest average for a flying kilometre on a public road (276.9 mph).

The two latter records had been unbeaten since 1938. Nazi engineers set them with a modified Mercedes W125 race car along a section of the German autobahn. It was overdue for a topple.

“We are in a golden age of high-performance cars right now,” said Eric Schmedding, the product manager for original equipment at Michelin. Schmedding woke at 5 am the day of the performance to monitor the single set of Michelin Pilot Sport Cup 2 tires the Agera wore for the duration.

“It took years to break the 200-mph mark, but now we are knocking on the door of 300 mph,” he said. “It’s a big game, with fierce competition, and it’s very fast moving.”

Indeed. While the auto and industries have garnered plenty of hype for self-driving and autonomous cars—appliances, really—the field of drivable, high-powered super cars has never been more exciting. 

The that set the record had a 1,360-horsepower, twin-turbocharged V8 engine and a power-to-weight ratio near that of the famous One:1 (so-named for its perfect 1:1 ratio). It also weighed just 1,395 kg (3,075 pounds), not including the factory-installed roll-cage used while completing the records. That sounds heavy, but it’s more than 1,000 pounds lighter than the 4,162-pound Bugatti that previously held the record and roughly 200-hp more powerful — two considerable factors.

But it was also adjusted for downforce, spokesman Steven Wade said on a phone call from the factory in Sweden. (Downforce is important for keeping a car stable as it accelerates and moves through space at high ) That proved the key factor to making the faster than the more powerful, more expensive, more insane One:1. Where the One:1 was aerodynamically calibrated specifically to handle the curves of a track — the shape of its front splitter, rear wing, and air vents all direct the flow of air in the way that eases changes in direction and calibrated the to optimise movement in a straight line.

“Agera doesn’t quite have the same quite dramatic aerodynamics [as the One:1], which it means it has less drag,” Wade said. “With less drag, you’re able to cut through the air quicker; with slightly less downforce, it’s better suited to a top speed, so this car was almost always a better candidate for a top record.”
 
The other main factors that allowed the to excel in Nevada are much more mundane: Tires and logistics.

After all, the has been available since 2015. The car that set the record is a true production vehicle, so in theory could have set the record back then. But it was only within the past six months that Michelin began working directly with to go for a moon shot.

“Tires are critical when you’re talking about a high-run like this—they are the potential weak link,” Wade said. “If anything should go wrong with a tire, you’ve got a potentially fatal situation, to be honest.”

For instance, that tiny valve stem where you put air into the tires on your 911 weighs 30 grams when you hold it in your hand. That’s about equal to a pair of Ray-Ban sunglasses. But when it’s rotating at 450 km/hour, it weighs closer to 170 kilograms, or 375 pounds, he said. That’s enough to affect the handling of the car or do serious damage as a flying object should anything go wrong.  

“It’s the centrifugal force,” Wade said. “So we had to rotate a wheel with that part in to make sure it would hold up. This hadn’t been done before, so we had to make sure. Luckily, it passed with flying colours.”

The deeper challenge was to mitigate heat, tire pressure, and wear at speeds faster than some airplanes travel at take-off. For the run, Michelin conducted the testing sessions at an aircraft testing facility in Michigan. Where some tires may have been able to sustain a high for a few seconds, these tires needed to be able to repeatedly withstand high speeds for minutes at a time.

“When you’re travelling at 250 mph, you’ve got to control for the growth of the tire,” Schmedding said. Heat and centrifugal force are the issue. “I kept checking everything run after run, and it all looked great. We felt comfortable. I just said, ‘Let’s keep going.’”

It’s no accident that the Porsche GT2 RS that just broke the Nurburgring record also used stock Michelin tires—the company outfits most of the automakers competing in this rarefied air, although it uses strictly different tires for each brand and don’t share data between brands, Schmedding said.

Each of the four Michelin Pilot Sport Cup 2 tires used for the record run consisted of a proprietary mix of rubber, thread compounds, steel bands, and filaments with Kevlar-style cords inside that allowed engineers to regulate the tension of each tire as it achieved top They were also made without the seams in the rubber that “normal” tires have, which can create heavy spots in the tire when run at high speeds.

NEED FOR SPEED
 
Driver Niklas Lilja averaged a top of 277.87 mph across two runs in the $2-million coupe on a 11-mile, closed-off stretch
The that set the record had a 1,360-horsepower and a twin-turbo charged V8 engine
It weighed just 1395 kg, not including the factory-installed roll-cage used while completing the records
It is more than 1,000 pounds lighter than the 4,162-pound Bugatti that previously held the record and roughly 200-hp more powerful
It beat the previous record of 267.8 mph set by a Super Sports model seven years ago in Germany

First Published: Mon, November 20 2017. 02:08 IST
RECOMMENDED FOR YOU