page_title: Plymouth Superbird
section_title: History
hierarchical_section_title: Plymouth Superbird / History
caption_attribution_description: English: 426 Hemi V8 Engine on a 1970 Plymouth Superbird
context_page_description: The Plymouth Superbird was a highly modified, short-lived version of the Plymouth Road Runner with well-known graphics and horn sound. It was the factory's follow up stock car racing design, for the 1970 season, to the Dodge Charger Daytona of 1969, and incorporated many engineering changes and modifications garnered from the Daytona's season in competition.
  The car's primary rival was the Ford Torino Talladega, a direct response to the Mopar aero car. It has also been speculated that a motivating factor in the production of the car was to lure Richard Petty back to Plymouth. Both of the Mopar aero cars famously featured a protruding, aerodynamic nosecone, a high-mounted rear wing and, unique to the Superbird, a horn which mimicked the Road Runner cartoon character.
  Superbirds equipped with the top-of-the-line 426 cu in Hemi engine with a pair of four barrel Carter AFB carburettors producing 425 hp could accelerate from 0 to 60 mph in 5.5 seconds.
context_section_description: Developed specifically for NASCAR racing, the Superbird, a modified Road Runner, was Plymouth's follow-on design to the Charger Daytona fielded by sister company Dodge in the previous season. The Charger 500 version that began the 1969 season was the first American car to be designed aerodynamically using a wind tunnel and computer analysis, and later was modified into the Daytona version with nose and tail. The Superbird's smoothed-out body and nosecone were further refined from that of the Daytona, and the street version's retractable headlights (made of fiberglass) added nineteen inches to the Road Runner's original length. The rear wing was mounted on tall vertical struts that put it into less disturbed air thus increasing the efficiency of the downdraft that it placed upon the car's rear axle. For nearly 30 years the mathematic formula used to determine the exact height of the enormous wing was thought to be a highly guarded Chrysler secret. In the 1990s, a retired Chrysler project engineer (falsely) claimed publicly that the height was determined in much simpler fashion: it was designed to provide clearance for the trunk lid to open freely. By coincidence, the height of the wing was at the optimum level for maximum downforce. The rear-facing fender scoops were to hide cutouts. These cutouts were to allow wheel clearance due to the taller, wider wheels and lowered the height of the vehicle for NASCAR competition. On Daytonas, the scoops were actually for ventilating trapped air from the wheel wells in order to reduce under fender air pressure and lift. For standard road going Superbirds the covers or "air extractors" were a cosmetic enhancement. Ground clearance was 7.2 inches (18 centimetres).
  NASCAR's homologation requirement demanded that vehicles to be raced must be available to the general public and sold through dealerships in specific minimum numbers. For 1970, NASCAR raised the production requirement from 500 examples to one for every two manufacturer's dealers in the United States; in the case of Plymouth, that meant having to build 1,920 Superbirds. Due to increasing emissions regulations, combined with insurance spike for high performance cars and NASCAR's effective ban on the aero cars, 1970 was its only production year.
  "Superbird" decals were placed on the outside edges of the spoiler vertical struts featuring a picture of the Road Runner cartoon character holding a racing helmet. A smaller version of the decal appears on the driver's side headlight door. Superbirds had three engine options: the 426 Hemi V8 engine producing 425 bhp (431 PS; 317 kW) at 5000 rpm and 490 lb⋅ft (664 N⋅m) at 4000 rpm of torque, the 440 Super Commando Six Barrel with 3X2-barrel carburetors producing 390 hp (290 kW) and the 375 hp (280 kW) 440 Super Commando with a single 4-barrel carburetor. Only 135 models were fitted with the 426 Hemi. As the 440 was less expensive to produce, the "street" version of the 426 Hemi engine used in competition was homologated by producing the minimum number required.
  On the street, the nose cone and wing were very distinctive, but the aerodynamic improvements hardly made a difference there or on the drag strip. In fact, the 1970 Road Runner was actually quicker in the quarter mile and standard acceleration tests due to the increased weight produced by the Superbird's nose and wing. Only at speeds in excess of 60 mph (97 km/h) did the modifications begin to show any benefit.
caption: 426 Hemi V8 engine on a 1970 Plymouth Superbird
exif: {"Image ImageWidth": "5312", "Image ImageLength": "2988", "Image Make": "SAMSUNG", "Image Model": "SAMSUNG-SM-G870A", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "G870AUCU1AOA1", "Image DateTime": "2017:04:05 13:34:29", "Image YCbCrPositioning": "Centered", "Image ExifOffset": "2318", "Image XPKeywords": "[69, 0, 98, 0, 97, 0, 121, 0, 50, 0, 48, 0, 49, 0, 55, 0, 0, 0]", "Image Padding": "[]", "EXIF FNumber": "11/5", "EXIF ExposureProgram": "Program Normal", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2017:04:05 13:34:29", "EXIF DateTimeDigitized": "2017:04:05 13:34:29", "EXIF ComponentsConfiguration": "YCbCr", "EXIF MaxApertureValue": "57/25", "EXIF MeteringMode": "CenterWeightedAverage", "EXIF FocalLength": "24/5", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "5312", "EXIF ExifImageLength": "2988", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "4810", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF FocalLengthIn35mmFilm": "31", "EXIF SceneCaptureType": "Night", "EXIF ImageUniqueID": "F16QLHF01SB", "EXIF Padding": "[]", "EXIF OffsetSchema": "4192"}