Cadillac invited Automobile Magazine to the GM Proving Grounds in Milford, Michigan, today to give us rides (not drives, although those will come soon) in its all-new, 2009 Cadillac {{{CTS}}}-V performance sedan. We might not have been allowed behind the wheel, but we came away with a new appreciation for what Cadillac engineers have achieved with this ultraperformance luxury sedan.
Let's get straight to the numbers, shall we? Cadillac's own testing has resulted in a 0-to-60-mph time of 3.9 seconds, and powertrain engineer Dave Mikels says that he is "confident that you guys [members of the media] will beat our time, since we ran our testing pretty conservatively." Cadillac has run the quarter-mile in 12.0 seconds at 118 mph. What's more, the CTS-V will not be speed-limited: the 2009 Cadillac CTS-V with automatic transmission will reach 175 mph, while the manual-transmission model will, according to Mikels, reach a breathtaking 191 mph.
The basic specifications of the CTS-V were announced last January, when the car made its debut at the Detroit auto show, but they bear repeating. Behind the big mesh grille and mesh air dam lays a supercharged, 6.2-liter, V-8 engine with an aluminum block and heads that produces 556 hp at 6100 rpm and 551 lb-ft of torque at 3800 rpm. The engine, known as the LSA within GM, is mated either to a Tremec six-speed manual transmission or to a Hydra-Matic six-speed automatic. Suspension is, of course, all-independent, and this is the first V-series Cadillac other than the XLR-V roadster to employ Magnetic Ride Control, which uses electromagnetically controlled dampers to maximize both ride comfort and handling stability. For CTS-V application, MR has a new magnetic fluid for more variation in damping performance at the extremes, allowing the dampers to be even cushier or even stiffer than they were before. Cadillac also specified new electronic controls for MR, so that each damper can react individually within 10 milliseconds. Nineteen-inch wheels shod with Michelin Pilot Sport rubber embrace fifteen-inch front brake rotors and 14.7-inch rotors at the rear.
The Cadillac folks are, understandably, giddy with excitement at the prospect of doing battle with the BMW M5 and the Mercedes-Benz E63 AMG. You would be, too, if your car had just set a lap record at the Nurburgring Nordschleife racetrack in Germany at 7:59:32. Cadillac believes it is the fastest recorded time for a production-spec sedan running on production tires. That's right: the car that set the German tarmac on fire was equipped exactly as CTS-V's will be at your Cadillac dealer when they start rolling off the production line in Lansing, Michigan, this October. The only modifications Cadillac made for the record run were the installation of a roll cage and racing seats and harnesses. "It looks like we may have achieved the milestone of [creating] the fastest production sedan in the world," crowed Cadillac's global chief engineer, Dave Lyon.
We got to ride along for one hot lap of the so-called "Lutz Ring" road course [named for GM vice chairman Bob Lutz] at the Milford facility today, with GM Performance Division head John Heinricy at the wheel, just as he was during the record run in Germany. The combination of this superbly tuned sedan, the same one that was at the Ring, and this world-class racing driver was exhilarating, to say the least. With the suspension and the automatic transmission both set to sport mode, Heinricy just left the gearbox in Drive, and we were always in the right gear (third, most of the time). The CTS-V was very stable, very composed, very fast, and very cool inside: in today's 87 degree temperature with high humidity, Heinricy gracefully left the A/C running, which did nothing to quell the car's amazing performance.
We got more passenger's-seat impressions, with powertrain engineer Mikels at the wheel of a manual-transmission model, around the proving ground's ride and handling loop and high-speed oval. Mikels performed several standing-start launches of the car to demonstrate that, unlike the first-generation CTS-V, the 2009 CTS-V does not suffer from rear-axle hop, the old car's greatest dynamic failing. "It's now virtually impossible to get wheel hop on a high-coefficient [of friction] surface," enthused Mikels, "and, trust me, I've tried." Mikels also assured us that "we got rid of the 'stirring oatmeal' feel of the old CTS-V's manual shifter, too."
Ed Piatek, program engineering manager for the CTS-V, elaborates on the steps he and his team took to eliminate the dreaded axle hop: "Cars with independent rear suspensions and a limited-slip differential are naturally prone to an oscillatory motion between the two half-shafts [which lead from the differential to each wheel hub]. They're like springs that you wind up, and because they have the same rate [of movement], as you unwind one, it transfers torque to the other, which sets up a ringing effect (resonance). By adding a larger, stiffer half-shaft to the left side, it stops the ringing, or the oscillatory windup, that leads to axle hop." How much larger is the left half-shaft? It is 2.2 inches in diameter, versus the one on the right, which is 1.4 inches in diameter. In the rear-suspension cutaway that
Cadillac showed us today, the difference was immediately obvious. "The left half-shaft," says Piatek, "is twice as stiff as the one on the right."
Cadillac engineers also established separate suspension algorithms for braking and accelerating modes to further prevent axle hop, or tramp. "At low speeds," explains Piatek, "we let the rear end take a set, but then we stiffen the rear dampers [using the Magnetic Ride Control] in rebound so the car stays down. We've also established an algorithm for the ABS that looks for differences in wheel speed. When we see that, we send a brake pulse to one of the rotors. It doesn't slow the car; rather, it merely slows one wheel, which prevents unwanted oscillatory motion."
Several tire-smoking, gear-banging launches of a manual-transmission CTS-V with Mikels behind the wheel indicated that all of these efforts have borne fruit. The CTS-V catapulted forward with grace, with very little in the way of lateral body motions, as we blurred the scenery on our way to an indicated 150 mph, a speed at which the car was barely breaking a sweat. And the 2009 CTS-V absorbed freeway-style expansion joints far more easily than you would expect from a hardcore performance sedan.
Mikels made two high-speed passes of the ride-and-handling loop, which is riddled with big dips, rough pavement, off-camber surfaces, chatter bumps, railroad tracks, and other real-world road conditions that wreak havoc on improperly tuned chassis. During our first run, he set the CTS-V suspension to sport mode, and the car soaked up every obstacle without a hiccup yet with a fair degree of suspension compliance. But even when Mikels set the suspension to comfort, the CTS-V handled all of what the engineers call "suspension events" easily.
Our rides in the 2009 CTS-V today came in the midst of what chief engineer Lyon calls "our final exam stage." Over the next week or so, Cadillac is driving a CTS-V for the equivalent of 24 hours at racing speeds, making sure the car is truly ready to take on the M5 and the E63. From what we saw, heard, and felt by the seat of our pants today, it looks like it surely will be.
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