Jeep ® JEEP HURRICANE Extreme Steering and Suspension MAE 442 Spring 2005 Richard Bennett Trent Boyd Kyle Goodrich John Walker Jeep ® A brief history The Jeep came into existence when the army needed to update its military vehicles just before entering World War II. It sent out a list of specifications for the new vehicle. These included: ● Load capacity of 600 pounds ● Wheelbase must be less than 75 inches ● Engine must run smoothly from 3 - 50 mph ● Rectangular shaped body ● Dual range four-wheel drive ● Windshield that folds down ● Minimum of three-passenger seating ● Blackout and driving lights ● Gross vehicle weight must be less than 1200 pounds Jeep ® A brief history The general purpose prototype featured: • A 2.2-liter four cylinder L-head style engine • 60 peak horsepower at 3,600 rpm for 100 hours straight • Four-wheel-drive transfer case with high and low gears. • An air cleaner was improved from earlier models • An oil filter that was placed high up for easy accessibility • A fold-up cloth roof • A six volt battery to power the headlamps, which were mounted on swinging levers in order for them to be pointed toward the engine for nighttime repairs • An engine that also powered the radar, radio, welding, and landing craft equipment • Front and rear axles that were simple if very hardy beams suspended by equally hardy leaf springs • Drum brakes at all four corners for reasonable stopping power Jeep ® A brief history The Jeep could : • Operate without strain from three to 60 miles per hour • Handle a forty degree slope • Turn in a thirty foot circle • Tilt left or right on a fifty degree angle without tipping over • Run under water with attachments for air intake and exhaust. Jeep ® The Future The Jeep Hurricane concept car Jeep ® The Future Jeep Hurricane Facts and Figures Engine: Two 5.7 liter, 8-cylinder HEMI engines Horsepower: 670 hp Torque: 740 ft-lb Transmission: 5-speed automatic Curb Weight: 3,850 lbs (1,746 kg) Length: 151.8 inches (385.6 cm) Width: 80 inches (203.2 cm) Wheelbase: 108.1 inches (274.6 cm) Wheels: 20x10 inches (51x25 cm) Tires: 305/70R20 (all four) 0-60 mph (97 kph): 4.9 seconds Jeep ® Suspension •The Hurricane has a four-wheel independent short/long-arm suspension system. •The system is dampened by coil-over shocks with remote reservoirs, which allows for longer travel in the shock. • It also sports 20-inch wheels to hold specifically designed off-roading tires that stand 37 inches tall. •Chrysler reports an angle of approach and an angle of departure of 64 degrees and 86.7 degrees respectively. •The suspension sports more than 14 inches of ground clearance and 20 inches of suspension travel. •The ground clearance is 5 inches greater and the suspension articulation is nearly triple that of Daimler-Chrysler’s most capable off- road Jeep production vehicle. Jeep ® Under The Hood •Two V8 HEMI engines. •Each 5.7L engine generates 335 horsepower and 370lb-ft of torque. •A grand total of 670 horsepower and 740 lb-ft of torque. •Daimler-Chrysler implemented its multi-displacement system onboard the Hurricane which allows for half of an engine’s cylinders to be deactivated when the vehicle does not require as much power, thus increasing fuel efficiency. Jeep ® Drive Train •The power that the Hurricane’s engines generate is delivered to its solid split axles through a central transfer case that incorporates a mechanically controlled four-wheel torque distribution system. •In this system, there is a driveshaft for each wheel instead of a single central driveshaft. •Most powerful vehicles, when put under tremendous acceleration, will have a tendency to twist their frames or to lift one of their tires off of the ground. This is partially due to the fact the rotation of the driveshaft creates a torque on the chassis in the direction of rotation, which puts additional down force onto one side of the vehicle, while lifting the other side. •Conversely, the Hurricane’s split-axle design applies down force to each wheel individually, giving it superior traction under acceleration. Jeep ® Drive Train Jeep ® Steering System •The Hurricane’s revolutionary steering system is an engineering marvel in and of itself. •The Hurricane has multiple steering modes which utilize four- wheel independent steering. •This equates to each wheel having the ability to turn independently of the others and enables three different steering modes. Jeep ® Performance •Because the Jeep Hurricane was designed with pure performance in mind, there are not many luxury features. •The body is a single piece of light-weight structural carbon fiber, which has remarkable rigidity for its strength. This means that the Hurricane can use the body as its chassis, instead of using a traditional frame. •All of the engine, transfer case, and suspension components are mounted directly to the body. •The skid plate of the Hurricane is an aluminum spine which also connects the body/chassis to the bottom of the vehicle. •There is also no roof, other than a few protective bars. •The Hurricane is only a concept prototype and will not be put into full production; however, Chrysler secured several patents during the Hurricane’s development. Now that these systems are fully functional and their engineers know how well these systems work, Chrysler could very well implement some of these technologies from the Jeep Hurricane into future production vehicles. Jeep ® The Hemi •Engines prior to the HEMI used what is called a “flathead” engine design. •The new HEMI uses a rounded, hemispherical shape in the combustion chamber, giving the unit a higher thermal efficiency and hence generating more power. Jeep ® The Hemi Advantages •The obvious advantage of a HEMI engine is the amount of power it produces as compared to other engines. •The HEMI is much stronger and much more efficient. •The HEMI design has less surface area inside the combustion chamber, thus reducing the amount of area for heat to be lost. •There is less heat loss and a higher pressure peak for power to be produced. •The thermal cycle is maximized and thus provides a higher efficiency or performance from the engine. Jeep ® The Hemi Disadvantages •The original HEMI engine could never produce a four valve per cylinder engine. •The valves would have to be configured in a way such that the engine would be near impossible to design and manufacture. •Drag and race cars are allowed only two valves per cylinder, making the HEMI ideal for this type of use. •Street cars do not need this extreme raw power, but rather a cylinder with more, smaller valves. This would allow the engine to breathe more efficiently and not overheat over long drives. •Another disadvantage that plagued the early HEMI designs was the emission problem due to the incomplete combustion of the fuel in the engine. Two spark plugs per cylinder helped increase the percentage of fuel combusted and hence improved the thermal cycle of the engine. Jeep ® The Hemi Disadvantages •Another reason why the HEMI engine is not used in all vehicles is the desire to even further minimize the combustion chamber surface area. •Therefore, the HEMI was designed with a “Pentroof” combustion chamber. The new HEMI design provides even less surface area for heat to be lost and four valves in the cylinder to improve conditions in the engine. Jeep ® The 2003 Hemi Model •Today’s newest HEMI engines build off the original designs of the first HEMI engine. •The new models still incorporate the hemispherical head and pride themselves on being the one of the most powerful and best performance engines in the world. •The 2003 Dodge HEMI carries on the tradition of HEMI engine and produces more power than any other listed engine and can also run at a higher rpm than other motors. Manufacturer Size (Liters) # of Cylinders Horsepower RPM Dodge 5.7 8 345 5400 Dodge 8.0 10 305 4000 GMC 6.0 8 300 4400 GMC 8.1 8 340 4200 Ford 5.4 8 260 4500 Ford 6.8 10 310 4250 Jeep ® Hurricane Steering •The new Jeep Hurricane as a completely revolutionized steering system. •The Jeep Hurricane uses the innovative “T-box” mechanism to utilize three different modes of steering using a four wheel independent steering system. •The “T-box” mechanism converts the opposite rotations from each Hemi engine and converts them to four independent rotations. •Four wheel independence is achieved with the “T-box” mechanism and a split-axel design. •With all four wheels independent from each other they can all be steered independently and rotated independent of each other. Jeep ® Hurricane Steering The three modes of steering that this can create are: • Standard Steering • Crab Steering • Zero Turning Radius Steering. Jeep ® Standard Steering Jeep ® Standard Steering •In standard steer mode the rear wheels turn in the opposite direction that the front wheels are turned. •This effect tightens the turning radius and allows for more accurate steering especially during a high speed turn. •The split axel design is also shown in the illustration. •The illustration also shows the opposing rotations from the Hemi engines and that the “T-box” mechanism rotates each individual drive shaft in different directions. •In standard steer the two drive shafts on each side of the vehicle rotate in different directions. Jeep ® Crab Steering Jeep ® Crab Steering •In crab-steer mode the rear wheels turn in the same direction that the front wheels are turned. •This effect allows the car to glide from side to side with out changing the steering of the car. •This same effect of the “T-box” mechanism is shown in the second illustration. Jeep ® Zero Turn Radius Steering Jeep ® Zero Turn Radius Steering •The third mode of steering is zero turning radius mode. •In this mode the “T-box” mechanism allows all four wheels to toe-in at about 55 degrees. •Also, the wheels on one side of the vehicle are spinning in the opposite direction from the wheels on the other side. •This creates a pivot point at the center of the Jeep and allows the vehicle to rotate in place. Jeep ® Zero Turn Radius Steering Jeep Hurricane in Zero Turn Radius Mode Jeep ® The Future •Just as the revolutionary design of the original jeep has influenced vehicles of the past, the new Hurricane will influence the vehicles of the future. •If adopted by the major auto manufacturers, the steering capabilities will drastically influence all other cars and allow consumers to do more with their vehicles than ever before. •Jeep is looking to use the new technology that has been developed for the Hurricane in both civilian and military vehicles. •Although the Hurricane is very advanced, its design only proves that there is much more for engineers to develop in the advancement of the automobile.