At the heart of the XLR-V is the 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. 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.
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.
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 roadster's 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.
Company press release, last updated on March 29, 2005
Ultimatecarpage.com
> Cars by brand
> United States
> Cadillac
XLR-V
At the heart of the XLR-V is the 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. 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. 
