Cadillac’s new twin-turbo system looks to kick turbo lag to the curb
by Dan Ilika
New Vsport models feature twin-turbocharged V-6 engine producing 420-horsepower, 430 lb.-ft. of torque
DETROIT—Anyone who has ever driven a boosted car knows that not all forced induction systems are created equal.
While superchargers are known for giving a stern shot of instant power to the drive wheels, they also have a reputation for pounding the pumps as much as the pavement.
The traditional turbocharger puts power and efficiency in the same package, but the lethargic lag of the average system can make the waiting game enough to make you feel like you’re driving a grocery getter.
That’s all about to change, if Cadillac has its way.
Added to the already boisterous Vsport line of luxury sedans, the Detroit automaker is launching its first-ever twin-turbo system to the 2014 CTS and XTS Vsport models, delivering boosted performance with little delivery time.
Slapped onto its 3.6-litre V-6 engine, the intercooled twin-turbo system pushes power to the tune of 420-horsepower and 430 lb.-ft. of torque in the mid-size CTS Vsport, making it one of the most power-dense engine in the segment.
“The Cadillac Twin-Turbo intercooler design builds on our experience with the 6.2L supercharged engine used on the current CTS-V Series,” Cadillac assistant engineer for the 3.6L engine Richard Bartlett said in a statement. “That means more performance for drivers without sacrificing efficiency.”
To deliver that added performance, Cadillac combined a top-mounted throttle body and shorter air pathways with smaller turbochargers to improve airflow and offer quicker turbo spooling.
“By creating a very short path from the turbos to the throttle body, the compressors are able to draw air directly from the inlet box and send pressurized air through the intercooler immediately,” Bartlett said. “This gives the driver a more immediate feeling of power on demand.”
According to Cadillac, air flow routing volume is reduced by more than 60 per cent when compared with a conventional design that features a chassis-mounted heat exchanger.
The water-to-air cooler system achieves more than 80 per cent cooling efficiency with only about one psi flow restriction at peak power for fast torque production.
The single, centrally located throttle body atop the engine controls the air charge from the two turbochargers after the temperature is reduced in the intercooler.
This design fosters more immediate torque response and reduces complexity by eliminating the need for a pair of throttle bodies.
Using two smaller turbochargers rather than a single, larger turbo also helps ensure immediate performance because smaller turbochargers spool up quicker to generate horsepower-building air pressure that is fed into the engine.
Together, smaller turbochargers, the top-mounted throttle body and shorter air pathways help sustain peak torque over a broad range—1,900 to 5,600 rpm.
The sedans put power to the pavement through Cadillac’s first-ever eight-speed automatic transmission.
The 2014 Vsport models are set to hit Canadian showroom floors this fall.
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