Text: Tito F. Hermoso / Photos: GM Press | posted February 25, 2013 13:33
GM Powertrains for the future, 2001
Twelve years ago, General Motors as we know it was a vastly bigger and different empire. With 9/11 just a month past, I wasn't surprised that the Nagoya-Detroit NWA 747 was 80% empty. During those days, flights to and from the US were constantly under surveillance by an airborne pair of JDF F-16s. And to think the Detroit winter hasn't set in yet. But air travel lock down or not, I was in Detroit to pay homage to world's biggest automobile company, General Motors.
Everyone calls Detroit Motor City. In all honesty, the real Motor City, the City of GM, Ford and Chrysler, is the entire state of Michigan including huge swathes of Illinois, Ohio, Indiana and south Ontario. Bigger than many countries, this region, is the home of the US auto industry, the sector that was to lead the US economy out of the shock of 9/11.
Getting from one corner of this huge agglomeration of interstates is all boring truck traffic and wall to wall speed traps. How can that be exciting? Well the Motor Industry has its guilty pleasures . And they have huge swathes of real estate to to indulge their R & D. GM's vast Milford Proving Grounds testing facility, covered from prying eyes by acres and acres of forest and private roads is such a place.
The last time such an event involving the engineers of GM's Powertrain was staged 3 years ago. This time they have more futuristic development 'toys' to share. And we would be able to drive these futuristic technologies, among the 25 or so dream cars from GM's rapidly integrating engineering empire from Suzuki, Isuzu, Subaru, FIAT, SAAB, Opel, Cadillac, Chevrolet, GMC, GM do Brasil, Saturn, Pontiac, Hummer etc.
Mind you, our route was not on some boring runway like skid pan. Or round and round again on some oval circuit. These are genuine roads, with forests, twisting corners and steep gradients. Some look like the New Jersey Turnpike, others like winding roads through the Catskills, complete with the right flora and maybe even fauna. The highways were smooth Autobahn and others decidedly good copy of crooked washboard surfaces from the Third World. There was a timed section to mimic thick Asian city traffic too. To make it all interesting, I was supposed to drive 25 prototype cars on this 12 mile test route, at any speed I like, all within a windy daylight.
You can call this a crash course in all kinds of vehicle propulsion of the future, for the coming ten years. There was plethora of acronyms to note take and remember. My favorite was the DOD technology or Displacement on Demand fuel saving technology. In essence, DOD cuts off half your V-6 to 3 or a V-8 to 4 working cylinders whenever you don't need all that extra grunt, which, in day to day driving is rather more often than not. What was amazing here is that even with a keen ear (or seat of the pants) the changeover from firing all cylinders to half was virtually imperceptible. Next was the VTi Continuously variable transmission automatic gearbox which gives you step less gears with out that disconcerting 'slipping clutch' revving that you get from the original Dutch DAF CVT cars. This was a huge improvement in response over the Fiat Uno-Lancia Y/10 and Subaru Justys CVTs of old as GM has successfully made this feel like a very snappy automatic transmission. There was an impressive 6 speed hydramatic for high torque engines that did away with the wasteful slipping torque converter by introducing a clutch to clutch shifting mechanism for more positive power delivery. On the opposite end of the scale, GM introduced the Easytronic, an automatic clutch manual transmission for European mini compacts.
There were high tech multivalve, with or without turbo, multi overhead cam engines in in-line 4, 5, 6 format or V-6 and V-8. A classic configuration V-12, akin to the 1932 Cadillac V-12, but of more high tech stuff than even the up to the minute North star V-8 tops the image/heritage stakes. GM's continued development of the Overhead Valve or push rod V-6 and V-8 engines continues despite the pillorying it got from some of the assembled scribes. The engineers, led by Tom Stephens and Dr. Fritz Indra of Opel's overhead cam-in head design team fame, were able to prove that any pushrod V engine can 1. rev as high as and develop as much power as any multi valve overhead cam design, 2. be inherently lower than overhead cam ones which is why Corvettes will always have an ohv option and that 3. have less frictional losses (less wasted energy) than a multi-overhead cam since there is only 1 cam nestling in the valley of the V and thus less parts. Hard to accept as most car-makers have abandoned the OHV-pushrod but the great and the good of GM made a most convincing case. To prove their point further, the strongest light duty truck diesel in the world, the Duramax 6.6 liter common rail 4 valve head, variable vane turbo co-developed with Isuzu has pushrods.
There were countless other electro regeneration hybrid technologies, variable valve lift, gasoline direct injection and a very normal to drive CNG (compressed natural gas) powered car but the most overwhelming theme was GM's painstaking determination to push the engineering envelope of power train efficiency. There was a secret car to tease us and it wasn't for the driving. Eight years later, it was revealed that that car is today's Chevy Volt all electric car.