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2009 Cadillac CTS-V – continued from page 1
– Rotocast aluminum cylinder heads
– Cast aluminum intake manifold
– 2 valves per cylinder
– Hydraulic roller valve lifters
– Sequential fuel injection
6.2L V8 ENGINE (LSA)
Supercharger
The LSA V-8 is equipped with a sixth
generation Eaton supercharger that
features Twin Vortices Series (TVS)
supercharging technology.The super-
charger displaces 1.9 liters per revolution
and generates a maximum boost
pressure of 9.0 psi (0.52 bar).
The four
lobe rotor
design
enhances
quietness
while also
optimizing the
performance
and overall
efficiency of
the engine.
Compared
with earlier
three lobe
rotor designs,
the amount of
power needed
to operate the
supercharger
is reduced by
about 35%.
Intercooler
The LSA's
intercooling
system uses
a single alu-
minum tube
and fin heat
exchanger
mounted
above the
rotors in the
supercharger
case. Air
pumped by
the supercharger flows down to the
intake ports on the cylinder heads. The
intercooler cooled by its own coolant
circuit, with a reservoir mounted in front
of the radiator.
LSA Oil
System
The oil
pump has a
capacity of
33.8 gallons
per minute,
for efficiency
during extend-
ed high-rpm
operation. The six-quart oil pan is fitted
with a liquid-to-air oil cooler.
TRANSMISSIONS
Two 6-speed transmissions are offered,
both manual and automatic.
Manual Transmission
The new TR6060 manual transmission
(MG9) is based on the proven Tremec T56
six-speed used in the previous CTS-V, but
is upgraded to handle the LSA engine’s
increased torque output.
It features both double-cone and triple-
cone synchronizers. A short-travel shifter
mechanism is used. Bearings are used on
the shift rail in place of bushings. This
reduces friction, making the shifter feel
lighter and more direct.
Twin Disc Clutch
A Luk 240 mm twin disc clutch uses
a pair of smaller diameter clutch discs
that have less inertia than a single, larger
diameter disc. This delivers improved
clamping power and excellent shift effort.
A dual mass flywheel is used for smooth,
rattle free performance.
Automatic Transmission
The Hydra-Matic 6L90 six-speed is
the first automatic transmission offered
in the CTS-V.
The transmission is a heavy-duty
version of the 6L80 six-speed automatic.
A strengthened input gearset has two
additional pinion gears (total of six). And
a strengthened output gearset uses
wider gears than the 6L80.
A twin-plate torque converter clutch
accommodates the torque output of the
LSA engine. This is the first twin-plate
configuration used with GM’s 300-mm
torque converter. Like the dual-disc clutch
of the six-speed manual transmission, the
twin-plate converter clutch provides addi-
tional clamping power.
Tap-Up/Tap-Down Shift Controls
Standard steering-wheel-mounted
paddles are provided for tap-up/tap-down
shift control. There is also a console-
mounted gear shifter control.
DRIVELINE
The driveline is mounted on a large
steel subframe that provides isolation
from the rest of the chassis. The rear axle
and differential assembly of the CTS-V
are upgraded to handle the additional
torque. The GT4 axle ratio is 3.73:1 with
the manual and 3.23:1 with the automat-
ic. The driveshaft has a larger outside
diameter and thicker wall, the limited-slip
differential housing is made of cast iron
and has offset mounts.
TIP:
Two different size half shafts are
used to counteract axle hop. The left side
is 55 mm, and the right side is 35 mm.
A Rear Differential Cooler kit is
available through Service Parts
(
TechLink
October 2008).
TIRES AND
WHEELS
Michelin
PilotSport 2
tires (255/40R-
19 front and
285/35R-19
rear) on 19-inch
alloy wheels
were developed
specifically for
the CTS-V.
Supercharger with
intercooler removed
Four-lobe rotor design
Intercooler, viewed from
bottom side
Engine oil cooler
TR6060 manual transmission (MG9)
Hydra-Matic 6L90 transmission
Rear suspension subframe
continued on page 3
