Zero to 60 miles per hour in less than 5 seconds. 415 horsepower under the hood. 125 feet needed to brake from 60 mph to a dead stop. Sounds like the figures you may expect to see if the Camaro ever gets a replacement, but these numbers belong to the 2006 Jeep Grand Cherokee SRT8. Designed to dust the Porsche Cayenne Turbo and BMW X5 4.6is, this Hemi-powered Jeep will also have no problem showing taillights to its corporate cousin, the Mercedes ML55 AMG.
The Dodge Street Racing Technology (SRT) engineers start with a Hemi V8 and bore it out, raising the displacement from 5.7 to 6.1 liters. Engine breathing is improved with larger intake components and headers feeding a 2.75-inch exhaust system with 4-inch tips in back. Hollow intake valve stems, sodium filled exhaust valve stems, a performance camshaft, a reinforced engine block, high-strength connecting rods, a forged steel crankshaft and a modified oil pan help to complete the picture. This setup allows the compression ratio to be increased from 9.6:1 to 10.3:1, and redline has been bumped up from 5-grand to 6,000 rpm. That's good for 415 horsepower and 410 lb.-ft. of torque.
Power from the 6.1 liter Hemi is sent through a custom torque converter to a strengthened A580 5-speed automatic transmission. To save 60 pounds, SRT engineers combined a lightweight transfer case with the rear half of a heavy duty case that houses the electronic all-wheel-drive system components. Five to 10 per cent of torque is always sent to the front wheels, and more is available when traction is lost in the back. Power gets to the rear wheels through a driveshaft from the European Jeep Grand Cherokee Diesel model attached to Dana 44 rear differential packed with a larger ring gear inside a bigger housing.
The SRT8 will sit an inch lower to the ground than the Grand Cherokee and has numerous improvements to the chassis. Along with new front knuckles, the suspension is enhanced with unique sway bars, custom spring rates and suspension bushings.
Four-piston Brembo brake calipers clamp down on 14.2-inch vented discs in front and 13.8-inch vented rear disc brakes. 20-inch polished aluminum wheels can be found at all corners wearing run-flat Goodyear all-season tires with 255/45/20 rubber in the front and 285/40/20 in the back.
While there has been no mention of low-range gears being made available, Dodge says a hitch package will be available that will allow towing of up to 3,500 pounds.
The 2006 Jeep Grand Cherokee SRT8 will be available in Bright Silver, Brilliant Black and Inferno Red paint schemes, and with only one interior available. The Medium Slate setup includes seats with suede inserts designed to hold occupants during aggressive maneuvers and some carbon fiber and aluminum parts along with SRT8 labels.