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| Like the Corvette, the heart of the CTS-V is the LS6 V8. The 5.7-liter V8 produces 400 hp and 395 lb-ft of torque, numbers that are more genuine than the carbon fiber-like nylon engine cover.
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The Cadillac CTS-V must compete against some very capable vehicles from Europe,
all of which sport technical exotica like overhead cam engines with four valves
per cylinder and variable valve timing. By comparison, the Cadillacs 16
overhead valves and pushrods sound trite at best. But when the valves are spread
out over eight cylinders displacing 5.7 liters, produce 400 hp @ 6,000 rpm and
395 lb-ft of torque at 4,800 rpm, and pull around 3,847 lb, the comparison takes
on a decided America vs. The World tone.
Design and engineering work on the CTS-V was carried out by GM Performance
Div. (GMPD) personnel working with John Heinricys High Performance Vehicle
Operations. Kip Wasenko, designer of the mainstream CTS during his days at Cadillac,
shaped the CTS-V from his new perch as GMPDs director of Design. But creating
a credible performance version of the CTS took more than just a shoehorn and
a body kit.
Under the Skin
The hydroformed front and rear cradles are larger than stock, and made of thicker
gauge steel. High-stress areas in the front suspension receive welded-in steel
gussets, the aluminum control arms are fitted with elastomeric bushings, and
a hollow steel cross-car brace supports the shock towers. Front spring rates
are up 27%, a 26.6-mm hollow anti-roll bar replaces the standard 23-mm hollow
bar, and the monotube front shocks are 10-mm larger (at 46 mm) and have unique
valving. Plus, a nine-land (valve element) steering gear replaces the standard
six-land unit. In back, the solid anti-roll bar increases 3 mm to 21 mm, spring
rates rise by 27%, and Sachs Nivomat dampers replace the standard units. The
brakes also have been upgraded, with Brembo calipers and discs at all four wheels
(355 mm x 32 mm, front and 365 mm x 28 mm, rear), and sit inside 18-in. wheels
shod with 245/45WR-18 Goodyear run-flat performance tires.
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| (V is the suffix for all future high-performance Cadillacs)
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The CTS-Vs LS6 V8 has a new induction system that draws air from three
front inlets, and exhales through a 2.5-in. stainless steel dual-exhaust system.
It also has a deeper oil pan, a lighter and more compact water pump, accessory
drives that are 37-mm closer to the block, and a redesigned exhaust manifold.
These are the only real changesother than the carbon fiber-effect (its
actually nylon) intake/valve cover shroudfrom the Corvettes version
of the LS6.
A dual-mass flywheel is used to eliminate gear rattle and pedal buzz,
especially at low speeds. To ease shifting and enhance reliability, the Tremec
T56 six-speed manual has double-cone synchronizers on third and fourth gears,
triple-cone units on second gear, and fifth and sixth gears (0.84:1 and 0.56:1
overdrive, respectively) are located on a countershaft separate from the first
four gears. Upgraded constant-velocity joints take power through a GKN-supplied
70-mm steel tube driveshaft to a revised rear differential with a thicker input
flange. The 3.73:1 limited-slip differentials aluminum housing incorporates
deep cooling fins on its lower surface, and a cast-in-place top grate for greater
cooling and rigidity.
Plastic Surgery
In order to differentiate the CTS-V from its more plebeian brothers, Cadillac
added unique front and rear fascias made of thin-wall TPO, with the front sporting
a thermoformed polyethylene aerodynamic tray and a stainless steel mesh lower
intake piece that matches the grille. Rocker panel covers are made of 3-mm thick
TPO, and extend 40 mm lower than the rockers on the standard car. Andfinally!the
large rear license plate holder is body color, not dark gray. Inside, the changes
are more subtle. Satin chrome trim rings surround each gauge, the center armrest
is 4-in. lower and shorter, all wood accents are banished, the seats have suede-like
inserts to hold the driver and passengers in place, and the driver information
center includes displays for peak and momentary lateral acceleration.
The lessons learned from the CTS-V will be used on its STS-V and SRX-V brothers
in the near future. All are based on GMs Sigma platform, which will make
their modification relatively simple. An XLR-V also is under consideration.
However, Cadillac general manager Mark LaNeve assures us one Cadillac wont
be receiving the hot rod treatment: There is no DTS-V.
Improving The Breed
When automakers talk of their performance offerings, the phrase a race
car for the road often finds its way into the marketing-speak, and not
always appropriately. The CTS-V race carthe CTS-V Ris heavily based
on the road car: 73% by weight, according to the program manager for the sedans
race program. The upright that holds the front suspension together,
says Dave Spitzer, starts out as a production piece, though we trim and
move things around a bit. The hubs come right off the production car and go
into the race car, as do the differential and halfshafts. The list is
long enough to suggest the marketing spin for this car more accurately might
be stated as: A road car for the race track.
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| The CTS-V R started as a production CTS that failed the paint quality test. But
CAD/CAM work, time in the wind tunnel, and more than 500 hp have a way of turning
an ugly duckling into a swan with an attitude.
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Work was well underway on the CTS-V when the racing program reached the planning
stages in September 2002. A test vehicle was ready by the following April, and
spent the year testing at many of the tracks on which it will compete in the
2004 Speed TV World Challenge series. In developing the race car,
says Spitzer, we used a lot of the facilities normally used by the production
teams to develop their vehicles. These included GMs wind tunnel
and seven-post shaker rig in Warren, MI, the Vehicle Handling Facility at the
Milford Proving Grounds, and a rig that swings the car like a pendulum so engineers
can analyze the height of its center of gravity and moments of inertia. We
just lined up in the queue like anybody else, says Spitzer. And the race
teamrun in conjunction with Pratt and Miller in Wixom, MIbrought
information back to the production engineers.
Early in the development process, the race cars Gen 4 V8 was hit by a
failure of the production intake valve. The team developed a fix with the valves
supplier, Eaton, and continued the test program with no further problems, never
expecting the same thing would happen to the production item outside the race
track. But it did. About three months later, says Spitzer, our
fellow from GM Powertrain, Tony Roma, was sitting in a meeting with the production
teams when one of them holds up a valve that had failed in the same manner.
Instead of a lengthy post-mortem and redesign, the production team members were
given a copy of the race teams fix. We saved them three months in
development time, says Spitzer proudly.
Despite all this sharing, one thing Spitzer is reluctant to share is the pain
that came with Cadillacs abortive three-year effort to win Le Mans. We
simply didnt know what we were getting ourselves into, and thats
hard to admit, he says. But I think its pretty clear we didnt
know how much Audi was bringing to the table. Or how much money (rumored
to be $165 million in the first year alone) the Germans were willing to spend.
All you can do in that situation is to start digging, says Spitzer.
We learned a ton, and our checklist is much longer and more robust than
before. Its a statement thats no doubt comforting to Spitzer,
but discomforting to those who must compete against him.CAS