Shift blocking is a feature of automobile manual transmissions added to improve fuel economy ratings in the Corporate Average Fuel Economy (CAFE) system by preventing a driver from switching from first gear to second or third as would be done normally. A solenoid prevents the shifter from engaging these gears, forcing the driver to shift from first to fourth gear. The solenoid is computer controlled, and will deactivate if the throttle is opened wide enough, or the car reaches speeds above those typical in city driving.
The skip shift feature was originally introduced in the Chevrolet Corvette in the late 1980s, [1] with the name CAGS (Computer-Aided Gear Selection), and is present on many sporting cars produced in the US from the 1990s onwards on every car fitted with the Tremec T-56 and TR-6060, including the Dodge Viper, [2] Pontiac Firebird, [3] 2004-2006 Pontiac GTO, Pontiac G8 GXP, V8/SS Chevrolet Camaro and Cadillac CTS-V. [4]
The effect of the system on normal driving has been described as "dreaded", [3] "awful" [5] and "annoying". [2] In 1994 Popular Science noted that "if something like an oncoming truck makes you change your mind, the car's response is doggedly slow." [6]
Owners manuals for the Corvettes in which it was first implemented contained photographs of the system components "captioned to caution drivers not to disconnect [the] wire, or the skip-shift function would no longer function." [1] These photos, along with the continuing, decades-long ability to bypass the system easily with a simple resistor, make it clear that GM has never intended to make the system difficult to bypass. If anything, it has been made as simple as possible while still satisfying federal regulations. Skip shift eliminators are produced for quick and simple DIY installation to circumvent the GM CAGS system. [7] In2005 [update] , these were commercially available for about US$20(equivalent to $28 in 2023)–$40, or could be made with a little soldering for about $7. [4] Notably, neither workaround will eliminate the "1-4 skip shift" dash indicator light, which will continue to operate regardless. ECU tuning is required to eliminate the dash indicator light.
The Chevrolet Corvette is a line of American two-door, two-seater sports cars manufactured and marketed by General Motors under the Chevrolet marque since 1953.
The Pontiac Firebird is an American automobile built and produced by Pontiac from the 1967 to 2002 model years. Designed as a pony car to compete with the Ford Mustang, it was introduced on February 23, 1967, five months after GM's Chevrolet division's platform-sharing Camaro. This also coincided with the release of the 1967 Mercury Cougar, Ford's upscale, platform-sharing version of the Mustang. The name "Firebird" was also previously used by GM for the General Motors Firebird series of concept cars in the 1950s.
Pony car is an American car classification for affordable, compact, highly styled coupés or convertibles with a "sporty" or performance-oriented image. Common characteristics include rear-wheel drive, a long hood, a short decklid, a wide range of options to individualize each car and use of mass-produced parts shared with other models. The popularity of pony cars is largely due to the launch of the Ford Mustang in 1964.
The F platform, or F-body, was General Motors' rear-wheel drive pony car automobile platform from 1967 until 2002. It was based partially on the GM X platform, which was used for compact applications instead of the sporting intent of the F-Body. The only two vehicles to have been built using the F-Body platform are the Chevrolet Camaro and the Pontiac Firebird. The fourth character in the Vehicle Identification Number for an F-body car is "F" on model year 1985 and up vehicles. Earlier Camaros and Firebirds had differing VIN codes, but are now commonly referred to as F-bodies.
The Chevrolet small-block engine is a series of gasoline-powered V8 automobile engines, produced by the Chevrolet division of General Motors between 1954 and 2003, using the same basic engine block. Referred to as a "small-block" for its size relative to the physically much larger Chevrolet big-block engines, the small-block family spanned from 262 cu in (4.3 L) to 400 cu in (6.6 L) in displacement. Engineer Ed Cole is credited with leading the design for this engine. The engine block and cylinder heads were cast at Saginaw Metal Casting Operations in Saginaw, Michigan.
The Iron Duke engine is a 151 cu in (2.5 L) straight-4 piston engine built by the Pontiac Motor Division of General Motors from 1977 until 1993. Originally developed as Pontiac's new economy car engine, it was used in a wide variety of vehicles across GM's lineup in the 1980s as well as supplied to American Motors Corporation (AMC). The engine was engineered for fuel efficiency, smooth operation, and long life, not for performance. Total Duke engine production is estimated to be between 3.8 and 4.2 million units.
The Chevrolet Citation is a range of compact cars that was produced by Chevrolet from the 1980 to 1985 model years. The first front-wheel drive Chevrolet, the Citation replaced the Chevrolet Nova as the automaker downsized its compact cars. Initially slotted between the Chevrolet Monza and the Chevrolet Malibu in the Chevrolet product line, the model line was later marketed between the Chevrolet Cavalier and the Chevrolet Celebrity.
Active Fuel Management is a trademarked name for the automobile variable displacement technology from General Motors. It allows a V6 or V8 engine to "turn off" half of the cylinders under light-load conditions to improve fuel economy. Estimated performance on EPA tests shows a 5.5–7.5% improvement in fuel economy.
The T-56 six speed manual transmission has been used in a wide range of vehicles from General Motors, Dodge, and Ford Motor Company. The transmission was originally designed and built by BorgWarner for the Dodge Viper later being used by GM in 1992 for the generation II and later engines, but from 1998 was built by Tremec, though nothing changed internally. The T-56 has been succeeded by the Tremec TR-6060 transmission in many former T-56 applications, as well as applications requiring greater strength than the T-56 could offer.
Turbo-Hydramatic or Turbo Hydra-Matic is the registered tradename for a family of automatic transmissions developed and produced by General Motors. These transmissions mate a three-element turbine torque converter to a Simpson planetary geartrain, providing three forward speeds plus reverse.
The Pontiac Banshee is a line of concept cars designed by Pontiac, assuming the role previously established by General Motors' Firebirds of the 1950s. Four Banshee "dream cars" were fabricated through 1988 as design exercises intended to establish exterior and interior themes that could be modified for production versions of Pontiac sports and performance cars. Banshee was also the leading candidate for Pontiac's version of the Camaro before being named Firebird in light of any deathly associations of the word Banshee.
The Chevrolet Corvette (C6) is the sixth generation of the Corvette sports car that was produced by Chevrolet division of General Motors for the 2005 to 2013 model years. It is the first Corvette with exposed headlamps since the 1962 model. Production variants include the Z06, ZR1, Grand Sport, and 427 Convertible. Racing variants include the C6.R, an American Le Mans Series GT1 championship and 24 Hours of Le Mans GTE-Pro winner.
The 4L60E is a series of automatic transmissions from General Motors. Designed for longitudinal engine configurations, the series includes 4 forward gears and 1 reverse gear. The 4L60E is the electronically commanded evolution of the Turbo-Hydramatic 700R4, originally produced in 1982.
A transmission control unit (TCU), also known as a transmission control module (TCM), or a gearbox control unit (GCU), is a type of automotive ECU that is used to control electronic automatic transmissions. Similar systems are used in conjunction with various semi-automatic transmissions, purely for clutch automation and actuation. A TCU in a modern automatic transmission generally uses sensors from the vehicle, as well as data provided by the engine control unit (ECU), to calculate how and when to change gears in the vehicle for optimum performance, fuel economy and shift quality.
The Tremec TR-6060 six-speed manual transmission features six forward speeds and one reverse speed. It is derived from the Tremec T-56 6-speed manual transmission. As usual, the forward helical cut gears are synchronized. However, the reverse gear operates through a fully synchronized constant-mesh system. The TR-6060 contains removable wear pads on the shift forks, and uses aluminum alloys for the main case, extension housing, and clutch housing. It is a double overdrive transmission. The TR-6060 is manufactured by TREMEC and is rated for 430 lb⋅ft (580 N⋅m) to 650 lb⋅ft (880 N⋅m) of torque, depending on gearing.
The Pontiac G8 is a full-size sedan that was produced by Holden in Australia for export to the United States, where it was sold by Pontiac. The G8, a rebadged Holden Commodore, was released in early 2008 for the 2008 model year in the United States, and in 2008 for the 2009 model year in Canada. Production stopped in mid-2009, following the GM decision to suspend the Pontiac brand. While available, the G8 took the place in the Pontiac lineup of both the Pontiac Bonneville, which ceased production after the 2005 model year, and the Pontiac Grand Prix, which ceased production after the 2008 model year.
Hurst Performance, Inc. was an American manufacturer and marketer of automobile performance parts, most notably for muscle cars.
The second-generation Chevrolet Camaro is an American pony car produced by Chevrolet from 1970 through the 1981 model years. It was introduced in the spring of 1970. Build information for model 123-12487 was released to the assembly plants in February of that same year. It was longer, lower, and wider than the first generation Camaro. A convertible was no longer available. GM engineers have said the second generation is much more of "a driver's car" than its predecessor. The high-performance Z/28 option remained available through 1975, redesignated as the Z28 in 1972.
The third generation Pontiac Firebird was introduced in late 1981 by Pontiac alongside its corporate cousin, the Chevrolet Camaro for the 1982 model year. These were also the first Firebirds with factory fuel injection, four-speed automatic transmissions, five-speed manual transmissions, four-cylinder engines, 16-inch wheels, and hatchback bodies.
The Dana/Spicer Model 44 is an automotive axle manufactured by Dana Holding Corporation and is used extensively among automobile manufacturers and in the automotive aftermarket area as well. The Dana 44 was first manufactured in the 1940s and is still being manufactured today, both front and rear axle variants. The Dana 44 has been manufactured as a beam axle and independent suspension for both front and rear axle setups. There are also different variations of the Dana 44. Over a dozen automobile manufacturers have made vehicles that have Dana 44 axles, including Jeep which currently manufactures four-wheel drive vehicles that have both front and rear Dana 44 axles.