SUBARU BOXERSLED

THE CHALLENGE

Subaru of America wanted to showcase the new WRX STI’s all-wheel drive capability with a never done before attempt to driven down the world famous St. Moritz-Celerina Olympia Bobsleigh Run. They called in Prodrive to help prepare the car for the extreme forces and buffeting the car would have to undertake to get down the run.

THE COURSE

The one mile course descends 426 feet down the mountain side through 19 turns, including the iconic Horse-Shoe turn, a steeply banked hairpin resembling a vertical wall. A four-man bobsled would reach 80mph on the course which competitors having to withstand forces of up to 5g during the Horse-Shoe. The forces endure are enough to distort almost any production car’s monocoque body. Prodrive applied bracing and reinforcing to cope with the extra forces and impacts.

SAFETY FIRST

Prodrive also fitted an FIA-spec roll cage, FIA-approved winged seat, harness, and a side protection net to ensure that the driver, Mark Higgins, wouldn’t be hurt if the car rolled. All the glass was replaced with race-ready Lexan plastic, which would stay in one piece in the event of an impact. Extra bumpers and scratch plates were fitted to minimise any damage as the car hit any side walls its way down the bob run. They were almost immediately torn off the car.

GRIPPING STUFF

Special anti-puncture tyres were fitted, despite only being about half of the width of a modern performance road tyre, each has 400 7mm tungsten carbide studs to give as much grip on the ice. To protect against deforming the tyres were over inflated to about 50psi.

DETAILS MATTER

Suspension was replaced with springs 50 per cent stiffer than normal and adjustable dampers were fitted and tuned. Prodrive fitted a tougher clutch and bigger AP Racing front brakes with brake pads suited to working in colder temperatures. The fuel tank was removed and replaced with a tiny 10 litre fuel cell.

WE CHALLENGE THE LIMITS

Having calculated the line and speeds needed, Mark successfully negotiated the WRX STTI to the bottom of the course in spectacular fashion.

To finally prove the the all-wheel drive capability, the Subaru WRX STI then made the return jounrey up the bob run to the start line.

TAKE A CLOSER LOOK