Designed to deliver ultimate performance for the ultimate cars, the race-bred Michelin Pilot Super Sport on sale in January 2011, boasts technology honed in the unforgiving environment of the Le Mans 24 Hours race and is so far the only tyre specified for the Ferrari 599 GTO. In independent tests the Super Sport was 1.5 seconds a lap faster on a 2700m track than its predecessor, the Pilot Sport 2, while its stopping distance from 50mph to 6mph was reduced by 3m. Now that’s progress.
Heat and dust in Dubai
Michelin launched the Pilot Super Sport at the Dubai Autodrome. It’s a useful facility for tyre testing in the depths of winter, the main race track backed up by wet circles and braking strips. To its credit, Michelin wasn’t shying away from caning its new tyres in public and had assembled some violent machinery to deliver the punishment. A long list included a 458 Italia, Koenigsegg Agera, Gumpert Apollo, Lamborghini Gallardo, Porsche 997s, an R8 V10 and a Mercedes SL-based MKB P1000 producing 1015bhp.
What makes ultra high performance tyres special
Simply being able to deliver levels of lateral and longitudinal grip needed to exploit the capability of a supercar’s power and handling, while not wearing out in five minutes. The Super Sport is derived from tyres developed for Le Mans cars including this year’s Peugeot 908 HDi FAPs and the winning Audi R15 TDI. Because of the longer distances covered and speeds achieved in the race, along with the results of independent tests, Michelin claims its new tyre is ‘the world’s fastest production road tyre on the racetrack’.
Top technologies keep the Pilot on track
A ‘Bi-Compound’ changes composition across the width of the tyre: at the centre, a high-grip elastomer improves wet grip and braking performance; while at the shoulder, the same formulation of carbon black used in the Le Mans-tyre resists wear when cornering. The carcass is constructed using weight-saving ‘Twaron,’ a strong, high density lightweight fibre, wrapped in a band around the tyre to prevent the centre ballooning at speed and reducing the size of the contact patch.
The ‘Variable Contact Patch 2.0’ by Michelin was modelled using software developed by aviation technology company, Dassault systems. Although it changes shape as the tyre deforms in action, the area in contact with the road stays pretty much the same. The new Pilot is more robust too, its wear rate 10 percent better than the previous Pilot Sport 2
How is it done?
Surprisingly, tyre development has a lot to do with sheer judgement rather than number crunching. Like other tyre companies, Michelin works closely with the car makers to design tyres perfectly tuned to the suspension and suited to the purpose of the car whether it be a supercar or limo. Human factors play a large part in getting it right and the interaction between car and tyre engineering teams is crucial. ‘It’s difficult to reach the targets later if you miss something at the beginning,’ says Michelin design team leader, Olivier Bouhet. ‘You must design close to the finished target from the outset.’
Tyre width, profile and wheel size has an impact on performance and, says Bouhet, ‘the tyre gets its stiffness from the air inside it’. So agreeing the optimum wheel and tyre size with the manufacturer at the outset is crucial. Design teams consider the load relationship between the axles and the effect that has on tyre pressures. If the figures change later, that may mean increasing tyre pressures and compromising performance and comfort. Too many ‘sipes’ in the tread blocks (those tiny slits that should improve grip) can cause dry grip to suffer as the tread blocks deform, forcing a switch to a harder compound to compensate, which in turn can affect wet grip. It’s complicated.
Michelin has a crack team of test drivers comprising Ferrari and Porsche specialists. Consistency is important to designing successful tyres and valued drivers have been in the team for between 10 and 15 years.
Behind the wheel of a 997 Carrera S and in warm conditions the Michelins felt sharper and more responsive than a competitor, albeit of an earlier generation. They also performed better on a wet circle and marginally better in straight line braking tests. Subjective but telling laps alongside a Porsche specialist driving a 997 were revealing. Rather than nursing the tyres, he deliberately and consistently piled into tighter corners just a little too late on the brakes presenting the Super Sports with an almost hopeless task. Despite that, the 997 showed no more tendency to washout on corner entry after a punishing four or five laps than it did at the first.
The tyres have also been tested independently by TÜV SÜD and achieved faster dry lap times and superior wet braking to leading competitors. Not all the latest tyres, such as the new ContiSportContact 5P, were used for all of the tests though.
The tests in Dubai were fairly subjective but the Super Sport was nevertheless impressive. Its rolling resistance isn’t much improved over its predecessor, the PS 2, which is surprising as Ferrari is chasing lower rolling resistance to improve its CO2 average. But there’s no doubting the Michelin’s robustness. Steering response and feedback is outstanding and the levels of grip high. In truth most premium tyres at this level are incredibly good and the new Michelin proves once again how far high performance road tyre technology has progressed in the last few years.