Plymouth Roadrunner

The Plymouth Road Runner is a mid-size car with a focus on performance built by Plymouth in the United States between 1968 and 1980. By 1968, some of the original muscle cars were moving away from their roots as relatively cheap, fast cars as they gained features and increased in price. Plymouth developed the Road Runner to market a lower priced, basic trim model to its upscale GTX.

Origin
Plymouth paid $50,000 to Warner Bros.-Seven Arts to use the Road Runner name and likeness from their Wile E. Coyote and The Road Runner cartoons (as well as a "beep, beep" horn, which Plymouth paid $10,000 to develop).[1] The Road Runner was based on the Chrysler B platform (the same as the Belvedere and Satellite), as a back-to-basics mid-size performance car.

1968
The earliest of the 1968 models were available only as 2-door pillared coupes (with a B-pillar between the front and rear windows), but later in the model year a 2-door "hardtop" model (sans pillar) was offered. The Road Runner of 1968-1970 was based on the Belvedere, while the GTX was based on the Sport Satellite, a car with higher level trim and slight differences in the grilles and taillights.

The interior was spartan with a basic vinyl bench seat, lacking even carpets in early models, and few options were available — such as power steering and front disc brakes,[1] AM radio, air conditioning (except with the 426 Hemi) and automatic transmission. A floor-mounted shifter (for the four-speed) featured only a rubber boot and no console so that a bench seat could be used.

The standard engine was an exclusive 383 CID "Roadrunner" V8 engine rated at 335 bhp (250 kW) and 425 lb⋅ft (576 N⋅m) of torque. Its extra 5 hp (4 kW) rating was the result of using the radical cam from the 440 Super Commando and a .25 raise in compression to 10.5:1 (vs. 10.25:1 with the 330 hp (246 kW) 383). When air conditioning was ordered, the cars received the 330 hp (246 kW) version, as the radical cam specs of the 335 bhp (250 kW) version did not create enough vacuum to accommodate air conditioning. A $714 option was the 426 CID Hemi rated at 425 bhp (317 kW) and 490 lb⋅ft (664 N⋅m) of torque.

The standard equipment transmission was a 4-speed manual with floor shifter and the three-speed TorqueFlite automatic was optional. Early four-speed 1968 Road Runners featured Inland shifters, which were replaced by Hurst shifters during the course of the model year.

Plymouth expected to sell about 20,000 units in 1968; actual sales numbered around 45,000. This placed the Road Runner third in sales among muscle cars with only the Pontiac GTO and Chevy's SS-396 Chevelle outselling it. Dodge debuted the Road Runner's cousin, the Super Bee, as a mid-1968 offering after seeing Plymouth's success with the Road Runner.

1969
The 1969 model kept the same basic look, but with slight changes to the tail lights and grille, side marker lights, optional bucket seats, and new Road Runner decals. The Road Runner added a convertible option for 1969 with 2,128 such models produced that year. All were 383 CID engine cars, except for ten which were equipped with a 426 CID Hemi.

An Air Grabber option (N96 code) was introduced this year; it consisted of a fiberglass air duct assembly bolted to the underside of the hood that connected to twin rectangular upward-facing vents in the hood with rallye red vent screens. The fiberglass hood box had an "Air Grabber" sticker on the front. When the hood was closed, a rubber seal fitted over the large-oval unsilenced air cleaner. A decal with Wile E. Coyote saying "Coyote Duster" was on the air cleaner lid.[1] The assembly ducted air directly into the engine. The vents in the hood could be opened and closed via a lever under the dashboard labeled "Carb Air." [3][1]

The 383 engine was standard with the 426 Hemi the only option available for the Road Runner until mid-year production. The 383 was marketed as the "383 Road Runner" engine.

The (A12) 440 engine option with three Holley 2-barrel carburetors was added to the lineup at mid-year. The "440 Six Pack" had no wheel covers or hubcaps, only the 15x6" "H" stamped steel black wheels with chrome lug nuts. It featured a black fiberglass lift-off hood with 4 hood pins and a large functional hood scoop with a red sticker on each side saying "440 6BBL". The scoop sealed to the large air breather. All cars had a Dana 60 rear axle with a 4.10 gear ratio. Production of the 440 6-BBL A12 option Road Runner was approximately 1,432. The A12 option had an "M" as the fifth character in the VIN. The 440 engine was rated at 390 hp (291 kW) @ 4,700 rpm, and 490 lb⋅ft (664 N⋅m) of torque @ 3200 rpm, the same torque as the Hemi but at a lower engine speed. The Plymouth Road Runner was named Motor Trend "Car of the Year" for 1969.[4]Domestic production for the three body styles was 81,125 with an additional 3,295 deliveries in Canada and other countries.

1970
The 1970 model year brought new front and rear end looks to the basic 1968 body, and it would prove to be another success. Updates included a new grille, a cloth & vinyl bench seat, hood, front fenders, quarter panels, single-piston Kelsey-Hayes disc brakes (improved from the rather small-rotor Bendix 4 piston calipers of '68 - '69 ), and even non-functional scoops in the rear quarters.[6] The design and functionality of the Air Grabber option was changed. A switch below the dash actuated a vacuum servo to slowly raise the forward-facing scoop, exposing shark-like teeth on either side. "High Impact" colors, with names like In-Violet, Moulin Rouge, and Vitamin C, were options available for that year. The engine lineup was left unchanged although a heavy-duty three-speed manual became the standard transmission, relegating the four-speed to the option list along with the TorqueFlite automatic. This was to be the second and last year of the Road Runner convertible, with only 834 made. The new high-back bucket seats shared with other Chrysler products which featured built-in headrests.

The 440 Six Barrel remained an option for 1970. The 1969 "M" Code Edelbrock aluminum intake was replaced by a factory-produced cast iron piece; however there were some early cars built prior to January 1, 1970 that were equipped with the left over aluminum Edelbrock intake from the year prior.

Sales of the 1970 Road Runner dropped by more than 50 percent over the previous year to around 41,000 units (about 1,000 ahead of Pontiac's GTO but still about 13,000 units behind Chevy's Chevelle SS-396/454). This would also be the last year of the Road Runner convertible with 834 total production. Only 3 Hemi (R) code Road Runner convertibles were built (plus 1 to Canada). The declining sales of Road Runner and other muscle cars were the result of a move by insurance companies to add surcharges for muscle car policies - making insurance premiums for high-performance vehicles a very expensive proposition. Also, Plymouth introduced another bargain-basement muscle car for 1970, the compact Duster 340 which was powered by a 275 hp (205 kW) 340 4-BBL V8 which in the lighter-weight compact A-body could perform as well if not better than a 383 Road Runner. Furthermore, the Duster 340 was priced even lower than the Road Runner and its smaller engine qualified it for much lower insurance rates.

Plymouth Duster l
The Plymouth Duster I was a high-performance concept car version of the Road Runner produced in the late 1960s. It featured the usual low-curved racing-type of windshield and had airplane-type flaps on the top and sides. A set of adjustable spoilers on the side of the rear fender (near the gas tank filler cap) helped prevent side-to-side yaw when slipstreaming in a race, with two more of them on top behind the driver, plus spoilers in the front as rock shields to reduce frontal lift. It was powered by a 383 4-BBL V-8.

1970 Superbird
During the 1969 NASCAR "aero wars", Chrysler first fielded the Dodge Charger 500 that featured aerodynamic improvements to a standard 1969 Charger. Later in the season Chrysler and Dodge debuted the Dodge Charger Daytona. The Daytona featured an elevated spoiler raised 23 inches off of the trunk deck by upright pylons and an aerodynamic nose cone. The Charger 500, especially, and the Daytona to a lesser degree struggled to equal the fastback Ford Torino Talladega and Mercury Cyclone Spoiler II in 1969. Dissatisfied with the performance of the 1968 Road Runner, Petty Engineering had asked the Chrysler managers for 1969 Dodge Charger 500s and Charger Daytonas for the 1969 season. The Chrysler managers told the Pettys that they were "a Plymouth team." The Pettys signed with Ford in days and Richard Petty and Petty Engineering won 10 races in 1969 and finished second in the NASCAR points championship.

To meet NASCAR homologation rules and also to bring Petty Engineering back to Chrysler, it was decided that Plymouth would get its own version of Dodge's winged wonder for the 1970 NASCAR season. While spectacular on the track, consumer response was lukewarm, leading a few dealers to remove the wing and nose, making them appear more like normal Road Runners. Significantly all public sold Superbirds had vinyl tops, while the Charger Daytonas did not. NASCAR only required 500 copies to be built in 1969, but in 1970, NASCAR required a manufacturer to build one unit per dealer. Production was 1,935 for the US market. Superbirds were available with three different engines. The most popular was the basic Super Commando 440 V8 with a single four barrel carburetor rated at 375 bhp (280 kW). Next up was the 440 Six Barrel rated at 390 bhp (291 kW). At the top, and ordered by just 135 buyers, was the 426 Hemi, rated at 425 bhp (317 kW). 135 Hemis (58 4-Spd and 77 Automatics), 1,084 - 440 4-BBL Super Commandos (458 4-Spd and 626 Automatics) and 716 - 440 Six Barrels (308 4-Spd and 408 Automatics).

According to Road Test magazine, performance was around 0 to 60 mph (97 km/h) in 5.5 seconds, 1/4 mile in 14.3 seconds at 104 mph with the Hemi.[8] Although similar in appearance, the Superbird was actually quite different from the Daytona. The Superbird was based on the Plymouth Road Runner and the nose, airfoil, and basic sheet metal was different between the Daytona and Superbird. The Superbird actually used the front fenders and a modified hood from the '70 Dodge Coronet that lent themselves better to the nose design. It was an easy fix due to the fact that the mounting points for fenders on both cars were identical. The special nose added 19-inches (483 mm) to the overall length (the Daytona's was 18-inches or 457 mm), and the trunk spoiler was more angled and higher than the Daytonas. On both models, the spoiler was two feet high. Although it created quite an impression on the street, the wing was not needed at normal highway speeds; it was designed for speedways, to keep the rear wheels to the ground at 150 mph (240 km/h) and higher speeds. The reason for using such a tall spoiler was to access 'clean air' according to the engineers who designed the spoiler. In test the spoiler didn't need to be so tall. The tallest the spoiler had to be was the same height as the roof.

Despite the success of the Superbird on the track, 1970 would be the only year it was made.