Computers v. Humans: Launch Control Tested - Feature

Smokeless Burnout Acid Test: We pit launch control against humans in a Corvette ZR1, a 911 Turbo S, and a GTI (for `Brent: ).

BY DON SHERMAN, PHOTOGRAPHY BY MARC URBANO, ILLUSTRATION BY BRYAN CHRISTIE DESIGN
June 2011
Pages: 1 2Photos





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</TD></TR></TBODY></TABLE>After the back-seat virginity-surrender ritual, the smoky burnout is our most precious teenage rite of passage. Who among us hasn’t waited patiently for the holy trinity—i.e., a fresh driver’s license, dad’s car keys, and a stretch of open road—to alight and grant our first taste of fire in the fenders?
Sadly, stick shifts, clutch pedals, and smoky burnouts are threatened by technology’s relentless march. We’ve endured such sacrifices before, but this time there is redemption. In exchange for some of our molten-rubber joy, we benefit from a worthwhile performance gain. Dozens of today’s cars offer launch-control (LC) systems that trade flaming Firestones for can’t-miss, computer-optimized, out-of-the-hole acceleration, managing engine output and clutch engagement to apply maximum torque to the pavement [see “Get Yer Launch Control Here”].
But can LC beat the best shoes in C/D’s test department? That’s what we’re here to find out, and we’ll do it by testing the automated versus handcrafted launches of three cars of differing layouts, transmission types, and driven wheels. First, though, a little backstory.
Electronic circuits began infiltrating cars half a century ago. A few ’64 Corvettes were equipped with transistor ignition systems. Anti-lock brakes arrived in the 1970s, paving the way for traction and stability control. Now that drive-by-wire throttles have become commonplace, it was inevitable that clutch operation would be added to the list of driving tasks taken over by algorithms stored in computer memory.
Launch control can at least claim regal roots. Two decades ago, Formula 1 designers began giving electronic controls broad authority over engine, transmission, braking, steering, and differential functions. Launch control was born in that era and quickly banned out of fear that smart computers would replace skilled drivers. Millions of lines of computer code needed to be monitored by the FIA for rules compliance, as some electronic controls were permitted while others, such as LC, were not. To avoid that hassle, all current Formula 1 cars share a spec powertrain computer that is not programmed with electronic LC. That said, it’s clear by watching the start of any Formula 1 race that engineers have contrived mechanical regulation of clutch engagement and fuel delivery to avoid smoky burnouts when the five red lights wink off  to start the event.
In 1989, when Ferrari debuted its F1 automated manual transmission on its F1/89 racer, Nigel Mansell found the technology handy for winning the Brazilian Grand Prix. From there, it was an easy walk to the first road-car application for an automated manual transmission (1997 Ferrari F355), followed by the introduction of LC in the U.S. market on the 2003 Ferrari 360 Challenge Stradale. Since then, more than a dozen carmakers have introduced nearly three dozen models offering smokeless burnouts.
Not surprisingly, the transition from the racetrack to the road has seen its share of drama. The Nissan GT-R arrived three years ago with ample power, tenacious traction, and a dual-clutch automatic serving as the go-between. Lacking an official LC mode, the GT-R left the building most expeditiously when its Vehicle Dynamic Control (VDC) system was disabled, resulting in a 4500-rpm clutch drop and a catapult hurl from rest. That thrill is addictive, and more than a few transmissions failed from too many hard launches packed into too few miles. When customers filed warranty claims, Nissan was understandably hesitant to cover the calamities because the GT-R’s owner’s manual clearly states that disabling VDC is intended only for extracting the car from mud or snow.
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</TD></TR></TBODY></TABLE>Nissan made amends by reprogramming the GT-R’s VDC to drop launch rpm to the 3000-to-3500-rpm range with VDC enabled. That 2010 model-year revision was offered to 2009-model owners but not before a class-action lawsuit ensued. For the face-lifted 2012 GT-R, Nissan added an R-Mode Start option to the VDC programming that enables a 4000-rpm launch. But four of them in sequence will disable that procedure until the car is driven in a sane fashion for at least 1.5 miles to cool off the hardworking clutch and transmission. As long as operators follow this less-abusive procedure to the letter, the GT-R’s warranty remains in force.
As the ever-changing protocols of the GT-R illustrate, there are no standard electronic or mechanical rules for how LC should work. Some cars have a dedicated button to initiate it; others use a secret handshake (a sequence of turning things on or off) to energize this performance mode. Much of the variety is born of layout: In automated single- and dual-clutch applications, for example, the controller limits launch rpm and regulates clutch engagement while the driver floors the accelerator before releasing the brakes (or the spring-loaded shift lever in a dual-clutch-equipped BMW M3) to initiate motion. In stick-shift applications, such as Corvettes, LC manages engine output to avoid overwhelming available traction. A front-driver like a Volkswagen is mainly concerned about limiting launch rpm because the front wheels deliver all the punch to the pavement. In powerful all-wheel-drive models, prudent engine-torque management safeguards the driveline.
In the end, though, every LC system strives to match torque to available traction on a millisecond-by-millisecond basis. At the very least, that means more consistent performance over a broad spectrum of road surfaces.Continued...

 

Launch Control, Anti lock brakes, stability control, rear camera, side avoidance warnings, etc.

Cars that park themselves...How long do you think it will be until we just get in a car & tell it 2 take us to where we want to go ~>~>2020 ?

 

Man takes all the fun out of driving. I love the way wifey grabs the dash and door handle when I take a curve at 50 rather than 25 and the rear end slides a little. I turn my traction controll off most of the time.