Source: General Motors
The 2006 Cadillac XLR-V – the newest addition to
the luxury nameplate’s growing family of high-performance V-Series
vehicles – establishes a new benchmark for the ultra-luxury class of
high-performance roadsters in power, performance and personal
amenities.
Like its mainstream XLR sibling, the 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:
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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;
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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;
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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;
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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.
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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 engine’s
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 world’s 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 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.
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.