The Virginia Tech Hybrid Electric Vehicle Team (HEVT) repeated a second-place performance at the EcoCAR 3 Advanced Vehicle Technology Competition (AVTC) held May 16-26 at the General Motors Desert Proving Grounds in Yuma, Arizona, and San Diego, California. It was the second year of the four-year competition cycle.
The AVTC is North America’s premier collegiate automotive engineering competition. It features 16 universities using a stock 2016 Chevrolet Camaro to integrate hybrid-electric designs in an effort to reduce the environmental impact of the vehicle while retaining the muscle and performance of the iconic car brand.
Of all the entries, only Virginia Tech committed to an eight-cylinder engine, using as its appropriate tagline in this election year, “Make EcoCAR V-8 Again.”
“Of the 16 teams, 14 of them took out the standard V-6 in the Camaro and used a four-cylinder engine,” said Doug Nelson, professor of mechanical engineering and faculty advisor of the team for the past 22 years. “One team used a two-cylinder configuration; but we wanted to keep the heritage of the Camaro and opted for a V-8 from a Chevrolet Silverado.”
It was a bold choice, but with the help of Blacksburg’s InMotion, a global supplier of electric motors, motor controllers, and equipment for the industrial vehicle industry, and a major sponsor of the team, the students were able to configure an electric motor and a hybrid propulsion system. Coupled with Flex Fuel technology that uses E85 (85 percent ethanol/15 percent gasoline), the team captured fuel and emissions efficiencies in two ways.
“The centerpiece of our design is the post-transmission motor,” Nelson said. “The students did the detailed mechanical design and InMotion did the electromagnetics design and built it, so it’s a completely custom motor designed to fit the space constraints of the vehicle.”
Nelson estimates the vehicle has a range of about 25-30 miles when run solely on battery power. Using the Active Fuel Management system found in the Silverado engine means effectively turning off four cylinders when demand is low. The team’s mission then was to maintain performance with the electric system to maximize the four-cylinder efficiency of the engine.
“Under limited loads, you can run the car on four cylinders, which is part of our hybrid strategy,” he said. “If you ask too much of the engine, it will move into eight-cylinder mode; but the electric motor and battery assistance minimizes that use. At the end of the day, we won’t have the best fuel economy … but we’ll have a V-8!”
The four-year competition evaluates teams on a wide range of details, including technical, safety, design, communications, marketing, leadership, and project management. While about 60 students will help on the team over the course of the academic year, 14 made the trip to Yuma and San Diego. First-year students and sophomores typically serve as volunteers and the bulk of the team is juniors and seniors with a few graduate students.
While most of the team is made up of mechanical engineers, there are also engineers from other disciplines, most notably electrical and computer engineering, and some from outside engineering, such as communications and public relations.
“The competition is about a lot more than just the work on the mechanical aspects,” Nelson said. “It’s not just the car – it’s about engineering and student development; doing and documenting all the engineering reports, the presentations, the communications and marketing. It has to do with preparation and giving a good presentation – but you can’t do that without good engineering data, so there are things to work on and refine outside the Ware Lab as well.”
The team will take the $9,000 prize for their second place finish to start getting ready for the third year of the competition schedule – what Nelson calls the refinement year. In that year, the team will fix issues or items that didn’t get resolved in year two. When the team heads to Detroit and Washington, D.C., next year, vehicle performance will figure more heavily in the scoring.
“We’ve got some work to do on the driveshaft and motor mounting, and one of the big things will be testing to see if we’re meeting our technical specifications,” Nelson said.
Nelson is confident that the program has been beneficial to the university and the students who participate.
“About half of our graduating seniors went to General Motors this year and quite a few returning students have internships with various automotive companies this summer, including GM,” Nelson explained. “There are a small number of what are called ‘key institutions’ for GM and Virginia Tech is one of those. It’s a partnership I’m proud to be a part of. Our students get hands-on lab experience as well as opportunities to engage with GM mentors assigned to each university participating in the AVTC. Keith Van Houten, manager of the Automated Driving Performance Simulation Lab with GM, is our team mentor, as well as GM’s lead recruiter for Virginia Tech, and an alum of the mechanical engineering program.
“This program succeeds because of the caliber of student who comes to Blacksburg, and the dedication and support of the college, the department, and all our sponsors, who are so helpful with their time and resources each and every year. It’s a privilege to be part of this team.”