The University of Arizona

UA's Baja Racing Team Will Campaign Two Off-Road Cars This Year

By Ed Stiles, September 25, 2007

UA's Baja SAE Team plans to build on last year's success by campaigning two vehicles in off-road competitions next spring.

The Society of Automotive Engineers (SAE) sponsors a series of Baja SAE races in the United States and Canada that pit small, 10-horsepower, off-road vehicles against one another in a series of events.

Last May, 102 college teams competed in an SAE Baja event in South Dakota and UA's team finished in 82nd place.

"I consider that a success because our team had never been to competition before," said Andrew Smock, a junior in mechanical engineering, who is captain of this year's team.

"We'd never built a vehicle before the South Dakota event, and we were all sophomores," he said. "But we solidly beat 20 teams that had established programs, and adequate funding."

The UA car, by contrast, was pieced together from parts of an old vehicle, and the team had a difficult time securing funding because they had no track record. Many prospective sponsors weren't sure the untried team could get to the competition.

"But we got there," Smock said. "We tried as hard as we could and came away with a wealth of knowledge that will really help us this year."

Team to Field Two Cars This Year

UA’s success last May has prompted several sponsors to get more involved this year, including Tomcar, a manufacturer of off-road vehicles in Phoenix.

Tomcar is donating $12,000 worth of parts to the team, including transmissions, wheels and other parts – enough material to allow UA's team to campaign two cars in at least one, and possibly two, of this year's Baja SAE series events.

UA's team will build a sturdy, heavier car with a wider wheelbase and larger tires designed specifically for rock crawling and hill climbing. The second car will be lighter, designed for fast acceleration and endurance racing. Once they reach competition, the team will split into two separate units to campaign the two cars. But during construction, team members will work on both cars.

Last May's event, which was sponsored by the South Dakota School of Mines in Rapid City, started with a tech inspection that involved checking about 100 different items on the vehicle to ensure that it met specs and would be safe.

After that, the cars were required to lock all four wheels on dry pavement to prove they had sufficient stopping power.

Then it was on to the main competitions in acceleration, maneuverability, rock crawling, hill climbing and endurance.

Full Roll Proves Durability of UA Car

The UA car proved its durability when it did a full forward roll off a jump, landed on its wheels and kept going during the endurance race.

Unfortunately, a little bit farther into that race, the car's left rear axle spindle snapped.

"We knew there was a small hairline fracture on the side of the axle, and we thought it would hold up as long as we were careful enough," Smock said.

It was a lesson learned. "Next year, we're not using any recycled parts," he said.

ATV Tires and Full Swing Arms

One innovation in this year’s cars will be the use of Tomcar’s durable wheels and tires in a dual swing arm setup for rear suspension. The system will be similar to having the rear ends of two motorcycles running side-by-side.

Each rear tire will be independently chain driven.

By eliminating the drive shaft between the wheels, the car will have several feet of clearance between the wheels and four-wheel-drive-like traction. If one rear wheel lifts off the ground the other one will continue to power the car, unlike an open differential setup in which all the power would go to the wheel that's off the ground. Smock noted that limited-slip differentials help cure the traction problem, but they're heavy.

The dual swing arm setup also should knock an additional 40 to 50 pounds off the car's weight.

Weight is even more critical on the SAE Baja cars than on full-sized off-road vehicles because the SAE cars are limited to stock, 10-horsepower Briggs & Stratton lawnmower engines.

During the summer, team members spent a lot of time modeling the new car in Autodesk Inventor software. "We are modeling all the components and mating them together in the computer and stress testing them," Smock said. "In other words, we're able to stress the car to failure before we ever build it."

UA Team Works to Build an Ongoing Effort

UA has fielded an SAE Baja vehicle off and on for the past 15 years, Smock said. Historically the UA car has resulted from a senior design project. But since the team members graduate after building the car, no continuity has been established from year to year. A car hasn’t been built every year, and each team has basically started from scratch.

"We're looking to create a team infrastructure that will last for many years to come," Smock said.

Many of last year's team members are returning this year. As the school year started, the team had eight returning sophomores and juniors. Smock said they hope to recruit a team of about 20 to 25 and to continue the team's diversity. In addition to engineering students, last year's team included those majoring in microbiology, business, and pharmacy.

The team also plans to take their cars to K-12 schools this year to interest students in pursuing careers in science and engineering.

Raytheon was a generous donor to last year's team, while T.A. Caid donated steel and aluminum to the effort. Motion Motor Sports and RS Engineering of Tucson also helped sponsor last year's team.

The 2008 SAE Baja competitions will be held in Tennessee, Illinois and Montreal, Canada. The UA team plans to compete in Illinois and possibly in Montreal.

Contacts

Andrew Smock

smock@email.arizona.edu

415-305-9385