Teaching an Old Tranny New Tricksbreathes next-generation life into the manual transmission
DETROIT - So here's Robert D. Welding, president and general manager ofInc.'s Transmission Systems - an outfit that's earned part of its iron-clad reputation by making critical components for automatic transmissions - effusing about an all-new technology to greatly expand the reach of manual transmissions.
Don't steel yourself for another tale of a perfectly reputable supplier's ill-considered "expansion" into a business it knows nothing about. BorgWarner knows transmissions - and never mind that it probably knows automatics a little better than it knows manuals. Because Mr. Welding's talking about turning manuals into automatics.
You've heard about so-called "automated" manual transmissions, and there are a couple, from the likes ofAG and SpA's Ferrari and Alfa Romeo, already in production. But BorgWarner thinks it can do better. And so does at least one major European OE: it will use the new BorgWarner technology for a production vehicle next year.
An engineer at heart, Mr. Welding likes to call the new technology a "layshaft automatic," but knows that's not likely to connect outside the pocket-protector crowd. So while the company works on a catchy trade name, we'll use the BorgWarner term "dual clutch transmission," or DCT.
That dual-clutch moniker is important, because that's what BorgWarner believes makes its system better. As with competing automated manuals, the driver pawns off the job of shifting to a horde of electronic sensors and hydraulic actuators and a brainy black box. There's no clutch pedal to finesse, no gear lever to move - drop it in "drive" and the electrohydraulic minions do the rest.
But BorgWarner's dual-clutch design is crucial, as it largely tempers a vexing bugaboo that plagues most contemporary automated manuals: "shift shock," or what the engineers like to call "torque interrupt." The effect occurs when the transmission shifts gears, causing a lurch or a jitter as the engine power is reduced, the clutch disengages, the gear is shifted and the clutch is re-engaged. With today's single-clutch automated manuals, the result is like riding with someone just learning to shift gears.
BorgWarner's DCT automated manual changes all that, because the technology uses two clutches. On one outer shaft reside first, third and fifth gears, along with a dedicated clutch. Placed on an inner shaft are second, fourth and sixth gears (along with reverse); this shaft, too, has its own clutch (see diagram).
Take, for example, a downshift from third gear to second. By staggering the gears on individually clutched shafts, the transmission can "phase out" of third gear while the other shaft has started to "phase in" second gear. This greatly reduces the "torque interrupt" sensation.
"The shift is done exactly like a conventional automatic transmission," brags Mr. Welding. "It feels just like an automatic."
That first customer will apply the DCT technology to a brand-new transmission, says Mr. Welding. The "modular" design means that the customer can sell the new transmission as a conventional manual, or fit BorgWarner's DCT module to offer the option of fully automatic operation.
"The critical piece of engineering is the wet friction (clutch) technology," says Mr. Welding. He says that BorgWarner's recent advances in friction materials - "We saw this (automated manual market potential) coming a few years ago" - play a vital role, along with high-tech lubricants and the capability of advanced electronic controls. The idea of automated manuals, he reminds, isn't new. But the contemporary developments now make the "idea" customer-ready.
And to paraphrase Priceline.com-shilling William Shatner, BorgWarner thinks automated manuals are going to be big. Really big.
In Europe that is.
Check out the charts and you'll see that European preferences are shifting toward automatics. By 2008, BorgWarner reckons automated manuals will capture a full 25% of the total European transmission market.
Europe is the key for a couple of reasons. First, the technology is "particularly attractive for Europe," says Mr. Welding, because inherent in the DCT design is the ability to use large hunks of existing manual transmissions; no lavish or expensive retooling is required for a move to DCT designs. The current manual transmission installation rate in Europe is a hefty 81%, and Mr. Welding says the DCT technology allows OEs to "take advantage of the manual transmission investment that's already in place."
Automated manuals also reconcile two divergent European automotive trends: the drive for increased fuel economy - still most effectively handled by a manual transmission - and European drivers' emerging preference for automatics, as roads and cities become frustratingly congested.
In the U.S., admits Mr. Welding, there's not much advantage, because fuel economy isn't an issue and the industry's manufacturing investment rests almost exclusively in automatics.
Now for the fuel economy thing: The automated manual kicks serious efficiency butt. Check out the chart above and note that when compared to the baseline conventional 5-speed planetary gear automatic, the 6-speed DCT delivers as much as a 15% increase in relative fuel efficiency.
And that figure whips the current darling of advanced-transmission promoters, the continuously variable transmission (CVT), a technology to which automakers such asMotor Co. and Corp. have recently made serious future commitments.
Belt-type CVTs also are hamstrung by their inability to handle the torque of largish-displacement engines, rendering them inapplicable for larger vehicles - i.e. the sport/utility vehicles everybody's buying - unless they're fitted with undersized engines.
No problems there for DCT, says Mr. Welding. "The dual clutch (design) places no special limitations on the gearbox," he claims. "The DCT approach can be scaled-up to meet any foreseeable application, and there is no torque limitation like there is with the belt-CVT approach."
"It's going to be a good fight between CVT and automated manuals," says Rob Smithson, drivetrain development group leader-design and NVH at Southwest Research Institute (SwRI), a highly respected independent research, development and testing facility. "The automated manual does make good sense, especially where manufacturing investment already is heavily biased toward conventional manual transmissions."
But he believes BorgWarner may be presenting an optimistic assessment of the DCT fuel economy gain.
"It would be a challenge to achieve that (13% to 15% increase) figure," he asserts. "You could get that, I suppose. Fuel economy gains for any given transmission depend on careful optimization of the overall system."
Nontheless, BorgWarner stands fast to the belief that by 2008, hundreds of thousands of vehicles will sport automated manuals.
"We don't think CVT technology can capture major market share," says Mr. Welding. And he thinks the more rudimentary automated manuals currently on the market will be relegated to entry-level models - once the industry gets a taste of the dual-clutch transmission.
Ah, what about the final frontier, cost?
Mr. Welding confidently predicts that cost will rest somewhere between today's automatics and manuals. When pressed, he says a typical industry cost for an autobox is around $1,000, a manual about $500; he pegs a DCT-outfitted automated manual at $850 to $900, adding that "it should be lower-cost than a conventional automatic or a CVT."
Europe, get ready.
BorgWarner Inc. probably is most famous for its four- and all-wheel-drive expertise. Particularly strong in the light-truck market, BorgWarner systems helped pioneer a new era of sophisticated, fully automatic 4WD systems.
With 4WD and all-wheel drive (AWD) continuing as a strong purchase-driver for sport/utility vehicles (SUVs) and a new wave of "crossover" vehicles, BorgWarner is aiming to usher in a new generation of advanced AWD engineering.
Robert K. Richardson, vice president, sales & marketing at BorgWarner's TorqTransfer division, says developing next-generation 4WD/AWD systems is coupled with new-age transmission development (see main story) to form the company's two-pronged model for future business growth.
Future AWD advances will be based on the newly introduced InterActive Torque Management (ITM) AWD system, says Mr. Richardson. The ITM system sees its first production application this year, fitted on theMotor Co. Ltd. Acura MDX SUV. BorgWarner worked with Honda for four years on the system, and now the MDX already has glommed onto some high industry praise, including being named Motor Trend magazine's SUV of the year.
The sophisticated ITM system resides at the rear axle of the MDX, which was designed for primary front-drive operation. When necessary, the ITM unit electronically apportions torque in any amount necessary to the rear wheels - even individually, if required.
The beauty of the side-to-side torque management from the ITM system, says Mark A. Perlick, vice president of engineering, is that its electronic control enables a level of "interaction" not available in more rudimentary "reactionary" systems that employ viscous couplings, for example.
"Computer-controlled (AWD) systems can do things manual-control systems can't," says Mr. Perlick.
Largely, Mr. Perlick is alluding to the potential to use AWD systems to influence vehicle handling - a new, higher level of stability control. ITM can do that - today.
"Future AWD must work with other onboard electronic systems," asserts Mr. Perlick. He says that ITM's technology can deliver a "predictive," active type of stability control not possible with today's brake-based stability control systems.
Both Mr. Richardson and Mr. Perlick believe that BorgWarner's ITM is the wave of the future - that as vehicles become more sophisticated, any type of 4WD system must work in concert with the entire vehicle.
"Passive 4-wheel drive will go away," says Mr. Richardson, "because of its inability to interact."