General Motors continues to pursue its “Road to Lab to Math” strategy that pushes more development work into the analysis realm in order to reduce the time and cost necessary to produce new powertrains. “We still need to test the vehicle for refinement,” says Dan Hancock, v.p., GM Powertrain Global Engineering, “but much of the earlier development work can now be done in math.” Hancock believes GM Powertrain’s new Engineering Development Center in Pontiac, MI, will improve calibration efficiency by as much as 50% as it rolls out 68 new calibration procedures that will reduce the number of on-road tests necessary to adjust powertrain parameters. “We’ve been able to determine the fewest number of data points necessary to produce statistically significant calibration curves,” he says, “which has allowed us to reduce our initial calibration time by 10 weeks (16 weeks on a dynamometer and undergoing analytical study versus 8 weeks on the dyno and 18 weeks of in-vehicle testing), and save more than $200 million.”
As expected, GM is running all of its engine test facilities on a common operating system and to a global standard, and projects can be run on a 24-hour basis by forwarding data around the world, if necessary. The use of common design models and laser alignment of powertrain components to their in-vehicle orientation guarantees repeatability, while the use of statistical engineering tools can reduce the length of longer tests by 85%. In addition, GM commissioned quick-change pallets to make dyno room changeovers as quick as possible. These U-shaped devices slide around a 1 to 2 ton powertrain cart, lift and float it on a cushion of air, and carry it into the dyno room. Because each test unit is built up or modified outside of the dyno cell, a complete changeover can be accomplished by one technician in 20 minutes without any tools and without taking the cell out of service. In the past, this process could take up to 24 hours.
The 450,000 ft2 addition also includes 120 flexible test cells, more than 100 component test stands, non-fueled loaded spin dynos, fueled powertrain test cells, and engine and transmission dynamic tilt test stands. The latter are capable of tilting an engine and transmission, separately or together, up to 53° fore-aft or side-to-side to replicate what they would see in extreme on-road situations. According to Tom Stephens, executive v.p., GM Global Powertrain and Quality, “This facility gives us the capability to design, develop, and test every conceivable type of powertrain faster than ever via a system that can run 24/7.”—CAS