Race engineers create ‘world’s fastest SUV’

COULD this be most powerful and quickest SUV ever made? The GKN Driveline engineers who worked with the SRT engineering team think so. They’ve strengthened a Jeep Grand Cherokee’s driveline, upgrading the rear halfshafts and propshaft to deliver the torque required to propel the 5300-pound SUV from 0-60mph in just 3.5 seconds.

“The aerospace-grade 300M high-strength low-alloy steel used for the Trackhawk rear halfshafts isn’t found on other high-volume passenger vehicles and it’s 42% stronger than existing Grand Cherokee halfshafts,” said Uwe Paksa, GKN Driveline Vice President CVJ Engineering. “We based the design on components from GKN’s motorsport division, and further upgraded the halfshaft thickness and strength to harness the 645lb-ft of torque generated by the supercharged 6.2-litre V-8 engine.”

Jeep Grand Cherokee Trackhawk drivers can select from five drive modes that adjust the torque split between front and rear axles. In Track mode 70% of the available torque is sent to the rear wheels. This represents the highest torque capacity for any halfshaft produced by GKN for volume-production vehicles. To confirm the durability of the components, the GKN halfshafts were subjected to fatigue testing that replicated the stresses of more than 2000 drag launches.

Similar halfshaft designs are supplied to GKN Motorsport customers competing in the World Rally Car (WRC) series and the gruelling 15-day Dakar Rally.