Peer inside the world’s largest and most technically advanced powertrain engineering development facility to see the latest testing tools being used on various fuel smart and emissions-free technologies of the future.
“We’re testing the Chevrolet Volt here. We’re testing all the two-mode hybrids here. This entire center has been designed to have the capability of testing all kinds of products, including gasoline, clean diesel, and biofuel engines, transmissions, hybrids, low-voltage, and high-voltage technologies,” said Larry Nitz, Executive Director of General Motors’ Hybrid Engineering.
The 450,000-ft2 (41,800-m2) GM Powertrain Engineering Development Center, located adjacent to GM Powertrain’s Global Headquarters in Pontiac, MI, links to GM’s 11 other global powertrain facilities via a common laboratory operating system that enables around-the-clock development.
Automated test procedures illustrate one avenue of 24-h testing. Using a Test Automation System (TAS), various parameters—such as vehicle mass and tire size—can be configured to run in predefined steps. When a test is running in an automated format, in-person monitoring is unnecessary. “If there is anything that would indicate (an issue), notification triggers are sent to us,” said Dave Stark, GM Powertrain Product Engineer.
Michigan’s new powertrain engineering development center builds upon the automaker’s ongoing Road-to-Lab-to-Math (RLM) process, an initiative that is transitioning some of the traditional powertrain testing done in a vehicle to advanced lab and CAE analysis. “We’re using statistical methods to monitor the test while it’s running to reduce the test from eight weeks down to about seven days,” said Craig Lash, GM’s Engineering Process Leader for RLM.
Another factor significantly altering the testing landscape is the 168 U-shaped pallets supplied by AVL. “This new pallet system increases test cell throughput and flexibility, which increases test cell utilization,” said Paul Durrenberg, Manager of Fueled Operations at GM Powertrain. The preparation process involves mounting a test article to a cart and then inserting the cart into a U-shaped pallet. All initial test setup occurs outside the test cell. One technician can move a pallet—loaded with the test article—into a test cell in about 20 min. Without the "quick-change" pallet system, the typical time to switch-out a test cell is 24 h.
The center contains more than 100 powertrain component test stands and 120 dynamometer test cells, including engine-dynamometer test rooms with emissions measurement capability for NOx, CO, aldehydes, alcohol, CO2, hydrocarbons, and particulates. “We can do heavy-duty emissions certification cycles, and we can simulate in these cells the vehicles that our engines will be integrated into. We’re able to obtain a great amount of data now from this very capable and very reliable testing system,” said Charlie Freese, Executive Director, GM’s Diesel Engineering.
Transmission testing done in the non-fueled area means performing “tests on our powertrains in the laboratory that were previously conducted in a vehicle. The input dynamometers in the non-fueled test cell are high-end and can simulate the performance characteristics of an engine. These cells are capable of running road load, engine, and vehicle inertia simulation,” noted Leanne Raney, GM Powertrain’s Manager of Non-Fueled Operations. The non-fueled area can also handle testing tasks for hybrid powertrain development.
Electric drive system development gets a boost at the new center. “We have electric motor testing capability at other sites, but we’ve more than doubled our testing capacity through this center,” said Nitz. "When we did our first generation of hybrids, we tested a lot of the motors inside transmissions, but now we can test a motor as just a motor.” The center’s several motor test stands are used to fully characterize motors prior to transmission integration and controls development.
To aid in developing oil sumps and fluid management systems that perform at optimal levels in all driving conditions, a dynamic transmission tilt stand substitutes for a vehicle. “It’s a lot faster for us to do tests in a laboratory environment than it is to do testing on a test track where you have to find a vehicle with the right content—meaning a certain transmission and a certain engine—and then find test track time on a day when there’s no ice, no snow, or no rain. With this dynamic tilt test stand, there’s a decoupling from all of those research constraints and bad weather days,” said Rick Gushman, Staff Project Engineer in the Test Technology Group. The dynamic test tilt stand, developed by GM and Moog FCS, is capable of 53 degrees of tilt in all directions as well as simulating accelerations in two axes up to 1.3 g with the transitions from zero to maximum g loads occurring in 2 s or less.
The new $463 million center effectively paves the way for General Motors to save time and money immediately. “We’ve reduced the time necessary to create our initial calibrations, saving us on average 10 weeks of critical development time in our programs,” said Tom Stephens, Executive Vice President of GM Powertrain and Global Quality. By year’s end, the automaker will realize $200-plus million in cumulative savings when “you combine the savings in North America with all of the global Road-to-Lab-to-Math initiatives within GM Powertrain,” said Stephens. When combining the 1200 employees being transferred to the new center from four other Michigan facilities (Ypsilanti, Wixom, Romulus, and Warren), the GM Powertrain Global Headquarters campus will employ approximately 4300.