Cadillac is touting its twin-turbo V6 engine with a video that explains the company’s strategy in reducing turbo lag.
Available in the 2014 CTS Vsport and the XTS Vsport sedans, the 3.6-liter V6 is rated at a healthy 420 horsepower and 430 lb-ft peak torque. Engineers say the turbo lag issue was addressed with a combination of smaller turbochargers, top-mounted throttle body and short pathways for the incoming air charge. The patented design also eliminates much of the heat-exchanger tubing to improve airflow as well as packaging. Instead, Cadillac mounts the air-to-water intercooler closer to the system, reducing the air-flow volume by 60 percent, when compared to a conventional chassis-mounted heat exchanger. The intercooler is also designed with more efficiency, reducing air flow by only 1 psi at peak power.
“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,” saysRichard Bartlett, Cadillac assistant chief engineer for the 3.6L engine.
Using two smaller turbos is also an advantage over a single, larger turbo as the smaller turbochargers spool up quicker. However, a single, centrally mounted throttle body is more efficient than two side-mounted throttle bodies and helps with torque response. Cadillac says torque is sustained over a broader 1,900 to 5,600 rpm range.
“The Cadillac Twin-Turbo intercooler design builds on our experience with the 6.2L supercharged engine used on the current CTS-V Series,” adds Bartlett.