Powering the 2018 Jeep Grand Cherokee Trackhawk is a supercharged 6.2-liter V-8 engine delivering 707 horsepower and 645 lb.-ft. of torque.
The breakthrough supercharged engine is designed and manufactured using only the strongest and most durable materials. Its cast iron block features water jackets between the cylinders for optimal cooling. A forged-steel crankshaft with induction-hardened bearing surfaces is so strong it can withstand firing pressures of nearly 1,600 psi (110 bar) – the equivalent of five family sedans standing on each piston, every two revolutions. The unique, specially tuned crankshaft damper has been burst tested to 13,000 rpm.
High-strength, forged-alloy pistons – developed using advanced telemetry measurement – are coupled to powder-forged connecting rods with high-load-capacity bushings and diamond-like, carbon-coated piston pins.
Premium grade, heat-treated aluminum-alloy cylinder heads are optimized for superior thermal conductivity. Sodium-cooled exhaust valves feature hollow-stem construction and special steel-alloy heads that stand up to temperatures as high as 1,652 degrees Fahrenheit (900 degrees Celsius).
The 2,380cc per revolution supercharger includes integral charge-air coolers and an integrated electronic bypass valve to regulate boost pressure to a maximum of 11.6 psi (80 kPa). The twin-screw rotors are specially coated with:
a proprietary formula of polyimide and other resins
nanometer-sized, wear-resistant particles
solid lubricants, such as PTFE (Teflon)
The coating enables tighter clearance between the rotors. This reduces internal air leakage, delivering improved compressor performance and higher efficiencies. The coating can withstand the temperatures generated by compression, and provides superior corrosion resistance.
The supercharger is sealed for life with premium synthetic oil, uses a drive ratio of 2.36:1 and has a maximum speed of 14,600 rpm. The supercharger drive system’s one-way clutch de-coupler improves refinement, while allowing for precisely the kind of powerful sound certain to captivate Jeep Grand Cherokee Trackhawk drivers.
Air sources for the supercharger include a cold-air scoop in the lower front fascia, which replaces the driver’s-side fog lamp and helps to feed the 92mm throttle body.
The large-nosed crankshaft drives a high-flow gerotor oil pump, which feeds a lubrication circuit that includes eight high-flow piston-cooling jets. A high-capacity oil/air heat exchanger, mounted in the front of the Trackhawk, mitigates oil temperatures when driving conditions are harshest, such as on the track.
A new low-temperature cooling system, consisting of a pump, reservoir, heat exchanger and lines, help keep the charge air cool during performance driving. This system is designed to keep intake air temperatures below 140 degrees Fahrenheit (60 degrees Celsius), under extreme ambient conditions, while enabling air flow of up to 30,000 liters per minute.
A new fuel delivery system, featuring two high-flow, multi-mode pumps, matches the high-performance demands of the engine.
Upgraded driveline components, durability and refinement result in benchmark off-road performance
The performance of the 2018 Jeep Grand Cherokee Trackhawk is bolstered by various upgraded driveline components engineered to handle the additional torque output from the supercharged engine.
The standard TorqueFlite eight-speed automatic transmission delivers improved shift response, quality and consistent performance and drivability. The transmission software takes into account variables such as engine torque gradients, kick-down events, longitudinal and lateral acceleration, grade changes, friction detection and downshift detection to determine the appropriate shift map.
Grand Cherokee Trackhawk is equipped with the Jeep Quadra-Trac on-demand four-wheel-drive system, which includes an electronic limited-slip rear differential and a single-speed active transfer case. The new, full-time active transfer case uses forged steel chain sprockets and a wider chain for added strength and durability.
A strengthened rear drive shaft connects to a new, stronger rear axle. The differential features a revised housing design, revised ring-and-pinion tooth geometry and new four-point axle mounting scheme for better load distribution, additional torque capacity and overall durability. Torque is delivered to the rear wheels via new ultra-high-strength 300M low-alloy vacuum melted steel half-shafts with upgraded eight-ball outboard constant velocity joints.
Standard Launch Control optimizes the Grand Cherokee Trackhawk’s performance by coordinating the engine, transmission, driveline and suspension for a textbook launch and consistent straight-line acceleration.
A new standard Torque Reserve system provides improved engine torque response and quicker vehicle acceleration in Launch Control by pre-positioning the supercharger bypass valve to generate boost and minimize manifold filling time, while cutting fueling to individual cylinders and managing spark timing. This generates a reserve of torque that can be instantaneously delivered upon acceleration from a standing stop.
The Selec-Track system on the Grand Cherokee Trackhawk uses performance-tuned software to pre-configure and distinguish the five dynamic modes, including: Auto, Sport, Track, Snow and Tow, enabling drivers to choose a vehicle setting that ideally meets their requirements and ambient conditions. The drive modes separately control the four-wheel-drive system, transmission, paddle shifters, suspension and the electric power steering.