A side impact accident is the most dangerous, due to the distance between the occupants and point of impact. The roll cage found in the MINI John Cooper Works WRC features door beams curve outwards.
The MINI WRC team has designed a new and ground breaking roll cage, with a unique side-impact structure for its debut into world rallying.
A side impact accident is the most dangerous, due to the distance between the occupants and point of impact. The roll cage found in the MINI John Cooper Works WRC features door beams curve outwards, which allows them to withstand greater impact forces and begin deceleration of the car sooner and for a longer period of time, significantly reducing the G-forces experienced by the crew.
The MINI WRC Team's Technical Director, Dave Wilcock, explained: "The new generation of rally cars are more compact than before, however we wanted to ensure that the crew were safer than ever and also that the car felt as spacious as possible. This brought some unique challenges."
"The Eureka moment was the redesign of the side impact protection bars, routing them farther away from each crew member and subtly changing their shape," explained Wilcock. "In an impact, this brings the structure into play much sooner, allowing softer materials to be specified to safely decelerate the crew over a much longer period of time."
An important factor in the project was the strength of the MINI Countryman bodyshell: "For previous rally cars, we have effectively ignored the original road car bodyshell in calculating the design of the roll cage. However, the Countryman is such a strong and safe car that we very much used this to our advantage and integrated it into the roll cage design, reducing the material we needed to add and so saving weight," said Wilcock.
Prodrive engineers subjected more than 50 sample roll cage joints to physical tests to see how each would fail, which led to complete redesigns of a number of joints and the use of different welding techniques and the application of a new grade of steel for the cage tubing.
The resulting roll cage is so safe, the FIA is now looking to make the unique side impact configuration mandatory in future designs of motorsport roll cages.Published 5 July 2011