Olympics: Inside BMW's Ultimate Bobsled Machine
The state-of-the-art two-man sled, designed at BMW's Designworks facility outside Los Angeles, has already helped the U.S. men's and women's teams sweep the podium in World Cup competition.
When Michael Scully stepped inside his first bobsled in 2011, he had just stepped out of an anemic rental car after an epic drive across Vermont to meet the U.S. bobsled team for their night practice runs at Lake Placid, N.Y.
As a designer of high-performance cars for BMW---his H2R hydrogen-powered car set nine world speed records--and a former race-car driver himself, Scully figuratively shrugged as he climbed inside a four-man sled piloted by Steven Holcomb, a driver for the team.
"On paper it was something I thought I would be prepared for because I had done a lot of car racing and was a competitive snowboard racer," Scully, 42, creative director of BMW's DesignworksUSA, told The Hollywood Reporter during an interview at his office outside Los Angeles. "On paper it was something I thought I would be prepared for--but within the first corner that hubris went out the the window."
Scully was stunned by "the level of forces and violence--it's absolutely terrifying. It made me question my mortality. It gives you a true appreciation of what these guys go through. It's a brutal experience."
Just as Great Britain and Italy have tapped the motorsport brain trusts at McLaren and Ferrari, respectively, to tune their Olympic bobsleds, BMW was chosen by the U.S. Olympic Committee to build the U.S. team, which hadn't won a gold in the two-man event since 1936, a better, faster sled. (Holcomb and the four-man team won the gold at the 2014 Vancouver Olympics.)
Scully's apocalyptic first run would go a long way toward informing many of the decisions he would make during the sled's two years of development and 149 design simulations.
"The level of vibration was a huge takeaway as far as design opportunity goes," Scully said, "because I've raced a lot of cars myself, and I know as a driver if you can focus or eliminate unnecessary inputs then you can be more precise. To try to quiet that chaos--it would be great if we could do that."
With some of the U.S. team's bobsleds more than 20 years old, Scully took as close to a clean-sheet approach as possible without running afoul of regulations which specify everything from the maximum and minimum weights of the sled to the basic design of the steering mechanism.
"When you have a limited amount of elements, that means those elements have to be optimized really, really well," Scully said. "Your solutions have to be absolutely spot-on."
Working within those parameters, Scully thought he saw a way to make the sleds faster by making them smaller--to reduce aerodynamic drag--and reducing and redistributing weight by using the same lightweight, robust carbon-fiber that is replacing steel in BMW's cars, to maximize stability.
"A core criteria was the frontal area of the sled--the reduction of that was always a huge priority," Scully said. "At the same time, the smaller you make the sled, the more centralized the weight becomes--the smaller and more centralized the mass, the lower, and less resistant to changes in direction it becomes."
Scully made extensive use of computer simulations, which were fed to a computer-guided mill that carved out full-scale models (some peripheral elements like fins were fabricated with 3-D printers). But some of the traditional tools of vehicle design--such as wind-tunnel tests, which visualize drag and airflow for a car traveling in a straight line--were of limited use for bobsleds, which are almost constantly changing direction and become nearly inverted on turns.
"You learn things, for sure, but wind tunnel tests are straight ahead, and a bobsled's almost never going straight ahead," said Scully. "At the end of the day, in a reasonably responsible budget world, you had to get it onto the track."
Scully recruited the U.S. team and solicited their reactions to working prototypes, where the steering mechanism in particular was fine-tuned for Holcomb.
"With Steve we have this relationship where it's an iterative process to tailor it to his wants and needs," said Scully. "He drives very much by feel--he was basically going blind for a good part of his career--and he developed this sixth sense where he wasn't driving visually, which is hard to believe."
After treatment Holcomb regained his sight and now has 20-20 vision, "but he still drives by feel," Scully said.
In the end, BMW produced a fleet of six two-man sleds, which yielded two U.S. podium sweeps since they entered World Cup competition late last year.
"It's great when they win, it's awesome," said Scully, "but for me the coolest thing was when the women's team completely swept the podium at Park City--it wasn't 1-2-3, it was 1-2-2 because they tied to the hundred of a second with two combined runs. The men one week later did the same thing in Lake Placid but it was 1-2-3. For the U.S. bobsled team to do that was supercool. For me that kind of signified that we haven't just elevated the equipment for one or two people--the whole team improves."
Scully will join the team and BMW's supersleds at Sochi but admits that he never rode in one after his tramautic run in Lake Placid two years ago.
Still, he said, "It's a sport I wish had discovered 25 years earlier--I love things that are designed for competition, because there's a clarity and focus, a reason for their shapes."