New Page 1
The drag racing Cobra
By Dennis Begley
In 1964, Carroll Shelby's A.C. Cobras dominated the American road racing scene.
The Shelby American racing team and independent Cobras won every race they competed in.
Shelby intended the Cobras to be street cars and road racers. Ford wasn't interested in
drag racing and therefore neither was Shelby American. Along the way, a few of Shelby's
employees convinced him to furnish them a 289 Cobra to build a drag version of the Cobra. They called it the
Cobras were ideal for modifying for the Strip. After all the whole car was a
hybrid to start with. The all aluminum body was made at AC in England. The engineless AC's
were shipped to the Shelby American in California to receive a Ford Hi-Po 289" - the
first American factory to be in the engine swapping business. Prior to this time, if you
wanted a V-8 powered sports car, you acquired a European car and put in your own American
engine. The public loved the cars. The A.C. Cobra was an instant success. The drag racing
public was accustomed to putting different, read that bigger, engines in cars for the drag
Almost every time the DragonSnake raced, it broke records. The driver, Jere
Kirkpatrick, also maintained the chassis. Ralph Falconer, Jr., was responsible for the
engines. Together they dominated the A/SP class. Top speed in the quarter for the 289
powered Cobra was 116.27 MPH in 11.81 seconds.
|The DragonSnake was modified for 1/4 mile racing. In the beginning the Cobra
couldn't get traction even with a factory stock racing engine. All four wheels were
independent, with springing by transverse semi-elliptic leaves. Weight transfer was the
key to getting the right traction. Special drag strip Cure-Ride shocks with 50/50 control
in the front and 90/10 in the rear that Up-Loc and Down-Loc on acceleration were
installed. In order to maintain proper front end geometry during hard acceleration, the
front springs were reformed down 2 1/2 " at the centerline and lengthened 5/16 "
. The rear spring was lengthened .350" to prevent the axles from changing to a
negative camber during acceleration. When the Cobra would leave the line, the body
shifting backwards on the rear wheels causing the tops of the tires to lean inward,
reducing the tire surface area in contact with the ground. Those were the only changes
made to the body of the sports car model.
Falconer came up with four engine combinations. All ended up being offered as
options on the Cobra roadster. The first stage I-D, was 271 HP 289". The same engine
with two four barrel carbs, rated at 300 HP, was stage 2. Swapping the two fours for four
Italian Weber carbs, jumped the horse power to 325, stage 3, III-D. Each engine was
carefully prepared to meet AHRA and NHRA standards. The last stage, IV-D, had the Webers,
a special acceleration camshaft with ported and polished heads. Rated at 380 HP, the IV-D
Cobras could only be raced in the AHRA sports car class.
Using a 4.89:1 rear end, the III-D Shelby Cobra outran everything on the drag
strip, even the fuel injected big block 'Vettes. The stuff legends are made
For more information, on the Dragonsnake Cobras, pick up a
copy of the Shelby American Registry from SAAC and Dave Friedman's book Shelby
Cobra, The Shelby American Original Archives 1962-1965. The information and
images come from the above sources. Friedman was the original photographer for
Shelby American. His thousands of images can be found in his series of books on
the cars of Shelby American. Invaluable additions to your collection of Shelby
American information. The pictures alone are worth the price of the books.
Definitely the stuff legends are made of...