Shifty Posted July 12, 2012 Report Share Posted July 12, 2012 Differences between the Cobras and Mustang GTs (and Mustangs) can be found everywhere - in the Engine, Powertrain and Chassis along with the obvious Body modifications. The 4.6 DOHC EngineThe 1996 Cobra was the first Mustang to use the 4.6-liter, double overhead cam, four-valve V8. The engine was heavily modified from the Lincoln version. The Cobra's aluminum block and heads were cast by Teksid, an Italian company that also casts components for Ferrari road and Formula One cars as well as other high-performance cars. Cast in Carmagnola, Italy, the Block uses cast-in ribbing for structural strength and to lessen vibrations. The cylinder bores have iron liners, and the engine's bottom end has been enhanced with a "deep skirt" meaning the bottom edge of the block extends well below the crankshaft's centerline, which also allows for a superior mating surface with the transmission. The crankshaft was forged by Gerlach-Werke in Homburg/Saar, Germany, and was then machined and balanced at Ford's Windsor, Ontario, Canada engine plant. The steel, heated to 2,300 degrees Fahrenheit (1,260 Celsius), is forged under 8,000 metric tons of pressure. There are counterweights placed opposite every throw of the crankshaft, which helps keep the engine's movement smooth. Mounted beneath the crankshaft is a unique windage tray that keeps excess oil away from the crankshaft and directs it to the Cobra's deep oil sump. The sump contains at least three quarts of oil even at sustained maximum revs. The Cobra's flywheel is made from nodular iron, an especially strong and durable metal. Also made of nodular iron are the main bearing caps. They attach to the block with six bolts to spread the tension and load over a greater area of the block. On each side of the cap, two bolts reach upward into the block in conventional fashion while one bolt runs horizontally into the side of the cap through the skirt of the block. The connecting rods feature larger, more robust ends than those found in any other Ford 4.6-liter passenger-car engine. The sinter-forged alloy rods are made from powdered metal that is compacted into the rough shape of the rod, then "hot-struck" in a forge. This results in a very strong finished product. After forging the connecting rod big ends were mechanically fracture-split to create the bearing cap. This makes the bearing cap and rod an exact fit, due to the irregular, interlocking surfaces along the fracture line, which makes the assembly especially strong. All main and rod bearings are made from aluminum, and are bored so the surface finish works in unison with that of the crankshaft journals. The shallow-skirt alloy pistons have a friction-reducing coating on their sliding surfaces to help reduce wear, and give a compression ration of 9.85:1. The engine was assembled at Ford's Romeo, Michigan, engine plant on a dedicated niche engine line staffed by 12 two-person teams. Each team is responsible for carrying an engine through the build process from beginning to end. When a team completes an engine, both assemblers affix their initials to the passenger cam cover. This engine was voted one of the 10 best by Ward's Auto World for 1996.The PowertrainThe Cobra engine begins the process of making horsepower behind the front grill, where a conical air cleaner sits ahead of an 80mm mass air sensor. The sensor measures the temperature and density of the air and feeds this information to the EEC-V - the electronic engine control computer. The air then moves on to the twin 57mm bore throttle body. The butterfly vales in the bores open simultaneously giving the engine excellent throttle body response and delivering large volumes of air to the cast alloy plenum that sits atop the Cobra engine. Eight equal-length cat thin-wall runners are placed inside the plenum. One runner feeds each cylinder - there is a Y split in the manifold just above the valves and this directs air to the primary and secondary valves - but only one of the two intake valves is fed at all times. The sequential port fuel injection system features one injector per cylinder. The injectors are placed directly behind the primary vales, and shoot fuel against the backs of the heated valve heads as they open. The fuel vaporizes instantly and is swept into the combustion chambers by the airflow. Placed above each secondary intake valve is a 34mm butterfly port throttle. Below 3,250 rpm, the port throttles are closed, thus blocking airflow to the secondary valves. With only one valve feeding each combustion chamber at low revs, airflow velocities are higher, and the mixture motion is faster, resulting in better cylinder filling and quicker, more complete burning of the fuel-air mixture. The curved lip around the inlet of the primary intake valve initiates and directs the mixture of the intake charge in the combustion chamber. This results in lower exhaust emissions and increased low-end torque. From 3,250 to 7000 rpm, the engine computer commands two things to happen: cables actuated by an electronic motor flip the port throttles, allowing a nearly unrestricted flow of air through all 16 intake vales at mid and high rpm (IMRC's); and the injectors provide more fuel to the cylinders. The port throttle design helps provide ample torque down low, while taking full advantages of the engine's high-end capabilities from the four-valve head design. The EEC-V computer monitors engine functions - airflow, crankshaft position, camshaft position - and can make minute adjustments millions of times a second to deliver the spark and air-fuel mixture at the optimum time to maximize power and fuel economy. Each cylinder bank has a dedicated coil, and ignition is achieved electronically, providing the kind of precision that a distributor and points cannot. The Cobra also has a sophisticated on-board engine diagnostics system. The Cobra's high-silicon, molybdenum iron exhaust manifolds feed exhaust gases into stainless steel dual exhaust designed with the fewest possible bends in order to maximize efficiency, and speed exhaust flow. A crossover pipe that balances the pressure pulses through the low-restriction mufflers links the exhaust pipes. The system is visually distinguished by twin 2.75-inch polished exhaust tips. The Cobra's oil cooling system embodies a new design concept developed by Ford. The water-to-oil cooler mounts directly to the left side of the block, with an oil filter mounted on it's end. Water returning from the radiator to the engine block first runs through the cooler, reducing oil temperatures significantly. The Cobra's transmission is the Borg-Warner T45. The gears are taller and wider than the T5 and incorporate revised gear tooth geometry, all of which provide a stronger gearset and reduce gear whine. First and second gears have large double-cone synchros to smooth engagement and increase durability. The reverse gear is removed from the movement of the geartrain when forward gears are engaged, further reducing noise and wear. The T5's extensive use of needle and roller bearings is continued in the T45, ensuring quiet and smooth operation. The clutch housing is integrated into the transmission assembly, providing a stiffer engine/transmission package and reducing powertrain noise and vibration. Power is delivered to the rear wheels through a limited-slip differential with a 3.27 axle ratio. The Cobra engine is free-revving from idle to its 6,800 rpm redline (fuel shutoff occurs at 7,000 rpm). It produces 305 horsepower at 5,800 rpm, and 300 lb./ft. of torque at 4,800 rpm; it generates more than 1 horsepower per cubic inch of displacement, and 66.30 horsepower per liter. The 1996 Cobra accelerates from a standstill to 50 mph in 4.7 seconds, and attains 60 mph in 5.9 seconds. It covers the quarter-mile in 13.99 seconds with a terminal speed of 101.6 mph. During testing it achieved a top speed of 152 mph. That's what magazines say. I ran mine at 13.5 @ 105 stock, and went over the 152 mph quoted by magazines.The ChassisIn creating the Cobra, Ford engineers started with the most rigid body structure of any Mustang built. To both enhance the strength and rigidity and accommodate the deep oil sump of the new engine, the No. 3 front crossmember was redesigned to increase the body's torsional rigidity and provide clearance for the engine. The front suspension is a modified MacPherson-type design, with a lower control arm, strut, and a unique 29mm stabilizer bar. The hydraulically assisted rack-and-pinion steering was also redesigned with helically cut steering gears to improve precision, feel and communication. The steering system runs in bearings rather than bushings to help increase reliability and reduce friction. The rear suspension follows Ford's Quadra-Link principles. An outbound lower trailing arm carries the spring near its midpoint and the axle near its end. A 27mm stabilizer bar links the two lower trailing arms, running behind and below the rear axle. Inboard upper trailing arms extend from the body structure to attachment points next to the differential housing. The shock absorbers stand vertically behind the axle assembly. Horizontally mounted hydraulic leading links help to locate the axle. The Cobra's unique 17.0 x 8.0 inch cast allow wheels are shod with 245/45-17 BFGoodrich Comp T/A ZR radials, which are derived directly from the Comp T/As fitted to the 1995 Mustang Cobra R race car. The Cobra's 13.0 inch vented front disk brakes feature twin-piston calipers sourced from PBR, an Australian manufacturer famous for its race-proven brake components. The iron rotors feature curved internal vanes that allow for effective and rapid dissipation of the heat that builds up under hard braking. The Cobra's brakes are monitored and controlled by a three-channel, four sensor Bosh ABS system that can modulate and adjust each of the four calipers every 10 milliseconds. This helps give the Cobra a 60 to 0 mph braking distance of 127 feet. The BodyThe Cobra is also visually distinguished from the Mustang and Mustang GT by numerous body enhancements. The round fog lamps in the front bumper, COBRA on the rear bumper, SVT badge on the trunk, Cobra badges on the front quarter panels and the unique raised hood with two forward facing vents are the most obvious. Inside the car, COBRA is spelled out on the Airbag cover on the steering wheel and the dash gages are white. Link to comment Share on other sites More sharing options...
330CubeGt Posted July 15, 2012 Report Share Posted July 15, 2012 Good bit of reading material here! Link to comment Share on other sites More sharing options...