With a top-mounted throttle body, a straightforward airflow design, and smaller turbochargers, GM’s new LF3 engine — which will debut in the 2014 Cadillac CTS VSport and XTS V-Sport — promises peak torque between a very broad 1,900 to 5,600 rpm.
Overall, air flow routing volume is reduced by more than 60 percent when compared to a conventional design that features a chassis-mounted heat exchanger, while the water-to-air cooler system achieves more than 80 percent cooling efficiency with only about 1 psi (7 kPa) flow restriction at peak power for fast torque production. By doing so, the engine’s compressors are able to draw air directly from the inlet box and send pressurized air through the intercooler immediately.
For the upcoming CTS VSport, the 3.6L V6 LF3 pushes out an SAE-rated 420 horsepower (313kw) and 430 lb-ft of torque (583 Nm), with slightly less than that for the XTS Twin-Turbo, at 410 horsepower and 370 lb-ft of torque. Those numbers are good enough to best BMW’s larger 4.4L TwinPower V8 found in the 550i — the direct competitor to the 2014 CTS VSport .