2006 Cadillac XLR-V

Like its mainstream XLR sibling, the Cadillac XLR-V combines distinctively bold styling with contemporary luxury, ingenious technologies, rear-wheel-drive performance, and near 50/50 weight distribution for enhanced balance and vehicle dynamics yet it does so on an entirely different level:

• Equipped with a supercharged Northstar engine and rear-mounted six-speed automatic transmission, the high-performance luxury roadster effectively delivers 0-to-60 performance in under 5 seconds;
• Exterior and interior appointments clearly identify the two-seater as a V-Series family member, including application of a signature wire-mesh grille, larger 19-inch wheels at all four corners, and ebony wood and aluminum accents throughout the interior;
• Chassis refinements enable surefootedness on the street or the track and include larger brakes, stabilizer bars, wheels and tires, a performance-calibrated Magnetic Ride Control (MR) system;
• An Adaptive Forward Lighting system, a first-time application on a Cadillac, which automatically adjusts headlamp direction up to 15-degrees for improved night driving vision.
• Like XLR, the XLR-V will be built at GM s state-of-the-art, award-winning Bowling Green assembly center.

Supercharged Northstar engine

At the heart of the XLR-V is the new, 4.4-liter version of the Northstar engine outfitted with a positive displacement intercooled supercharger. The dual overhead cam (DOHC) V-8 engine delivers the highest horsepower rating of any Cadillac engine to date.

Called the Northstar V-8 SC (supercharged), the engine produces 440 horsepower (328 kW) at 6400 rpm and 425 lb.-ft. (576 Nm) torque at 3600 rpm (power and torque figures estimated) and the engines power is underscored by its ability to deliver 90 percent of its peak torque between 2200 and 6000 rpm.

The Northstar V-8 SC generates 120 horsepower (90 kW) and 115 lb.-ft. (156 Nm) of torque more than its naturally aspirated counterpart, while its specific output of 100-horsepower-per-liter makes it one of the worlds highest specific output production V-8 engines.

However, the Northstar V-8 SC used in the XLR-V is more than just power and torque. The DOHC engine includes variable valve timing that enables outstanding top-end performance while maintaining the expected refinement and quality associated with a luxury marque.

The aggressive torque curve enabled by the choice of a supercharged engine gives the XLR-V acceleration capable of placing it firmly in the under-5-second-club for 0-to-60 time a signature capability of V-Series vehicles.

The refined shift feel is enabled by careful electronic calibration of both the engine and transmission. During shifts, power is instantaneously lowered, then ramped back up carefully to make gear changes virtually unnoticeable.

Air induction & exhaust

The air induction system on the XLR-V was redesigned to address packaging needs created by the larger engine and addition of the supercharger.

These modifications increased the flow of air to the engine by 30 percent, funneling it from the front air intake over the radiator and to the supercharger via two ducts, which converge into one prior to reaching the supercharger so only one mass air flow sensor is required.

The system was designed to be as free flowing as possible, bringing in the maximum amount of air to the supercharger. Each duct has been carefully tuned to minimize supercharger whine and resonance in order to achieve the most pleasing intake sound quality.

The exhaust system features a unique muffler design, which effectively combines the construction of a more conventional muffler with a high-performance flow-through design. In order to keep sound levels at a pleasant, throaty pitch during everyday driving on streets and expressways, the exhaust is routed through a series of internal chambers that muffle sound levels . During more aggressive driving, a vacuum-actuated Pierburg valve in the muffler opens to allow straight exhaust flow-through. There are some perforations in the pipe to allow some dissipation into the other muffler chambers, but the overall effect is to reduce backpressure and increase power.

Six-speed automatic transmission

The Northstar V-8 SC is mated to the all-new Hydra-Matic 6L80 six-speed automatic transmission the first use of General Motors new six-speed automatic in a rear-mounted configuration.

The 6L80, the only transmission offered on the XLR-V, is one of the most technologically advanced automatic transmissions in the industry, using clutch-to-clutch operation and an advanced integrated 32-bit transmission controller to deliver smooth and precise shifts. In addition, a wide 6.04:1 overall ratio spread enhances performance and fuel economy.

The 6L80 also incorporates a host of advanced driving enhancement features, including advanced Performance Algorithm Shifting (PAS), Performance Algorithm Liftfoot (PAL), and Driver Shift Control (DSC).

PAS lets the electronic transmission controller override the automatic gear selection during closed throttle high lateral acceleration maneuvers, rapidly downshifting with the release of the torque converter clutch for smooth powering up when the throttle is reopened. PAL minimizes transmission upshifts during closed throttle driving and cornering to maintain the correct gear and alleviate busyness. Driver Shift Control allows the driver to sequentially shift gears manually via the gearshift lever.

Performance-tuned chassis systems

Chassis modifications found on the XLR-V when compared to its mainstream sibling include larger brakes; recalibrated Magnetic Ride Control (MR); larger front stabilizer bar and the addition of a rear stabilizer bar; stiffer rear lower control arm bushings; larger wheels and tires; a power steering fluid cooler; and a higher-capacity fuel pump.

The most noticeable change is in the braking system to assure strong stopping power and smooth, confident brake operation, coinciding with the increased power and handling capabilities of the XLR-V.

To achieve this, chassis engineers turned to J55 brakes, essentially the same application used in the Z51 Corvette with larger cross-drilled rotors and high-performance brake lining. Front rotors are 13.4-inches (340.4 mm) in diameter; rear rotors are 13.0-inches (330.2 mm). The thickness of the rotor cheeks on both the front and rear has been increased for added thermal capacity. The brake system incorporates dual-piston front calipers, and single-piston rear calipers.

Magnetic Ride Control on the XLR-V has been recalibrated to account for the enhanced handling characteristics the roadsters surpercharged performance demands. The system seeks to keep the body on an even plane at all times, giving drivers a comfortable ride by dramatically reducing disturbances to the vehicle body.

The MR recalibration combined with a stiffer front stabilizer bar, the addition of a rear stabilizer bar, and stiffer rear control arm bushings subtly changes the driving characteristics of the XLR-V when compared to the standard XLR. Another V-Series staple is a four channel/four-selection mode chassis control system (StabiliTrak), enabling the driver to switch between four stability settings, including a "less-governed" performance mode for the performance enthusiast.

Wheels and tires have been increased in size for enhanced sure-footedness, to 235/45R-19 on the front and 255/40R -19 rear. The tires are Pirelli run flats.