Chevrolet Corvair: Encyclopedia II - Chevrolet Corvair - Modifications

Chevrolet Corvair - Modifications

Many sports car purists were more interested in the Corvair (particularly the 1965 and later cars) than in more conventional designs, such as the Ford Mustang, despite the latter's power advantage. From the first appearance of the Corvair, a large selection of high-performance equipment and modifications became available for it.

Chevrolet Corvair - Yenko Stinger

Don Yenko, who had been racing Corvettes, could not compete successfully against the Carroll Shelby Mustangs after they arrived on the scene; he therefore decided to race modified Corvairs, beginning with the 1966 model. As the stock Corvair did not fit into any of the SCCA categories, Yenko had to modify four-carburetor Corsas into "sports cars" by removing the back seat; in the process he would introduce various performance improvements. As the SCCA required 100 cars to be manufactured to homologate the model for production racing, Yenko completed 100 Stingers in one month in 1965. Although all were white, as the SCCA required for American cars at the time, there was a great deal of variety between individual cars; some had exterior modifications including fiberglass engine covers with spoilers, some did not; some received engine upgrades developing 160, 190, 220, or 240 hp (119, 142, 164, or 179 kW). All were equipped by the Chevrolet factory with heavy duty suspension, four speed transmission, quicker steering ratio, positraction differentials (50 with 3.89 gears, and 50 with 3.55 when Chevrolet dropped the 3.89) and dual brake master cylinders (the first application of this by Chevrolet, to become stock equipment the next year). The Stingers competed in Class D Production, which was dominated by the Triumph TR4, which was very quick in racing trim; however in its first race in January 1966, the Stinger was able to come in second by only one second. By the end of the 1966 season, Jerry Thompson had won the Central Division Championship and placed fifth in the 1966 Nationals, Dick Thompson, a highly successful Corvette race driver, had won the Northeast Division Championship, and Jim Spencer had won the Central Division Championship, with Dino Milani taking second place.

The next year, however, Chevrolet dropped the Corsa line, and the Monza line was not initially available stock with the four carburetor engine; the engine was eventually offered as a special performance option, however, along with the 3.89 differential. The Monza instrumentation, however, did not have a tachometer or head temperature gauges, which had to be separately installed. The SCCA, on the other hand, had relaxed its ruling regarding color, and the cars were available in red or blue. It is believed that only fourteen 1967 Stingers were built, but Dana Chevrolet, who distributed Stingers on the US West Coast, ordered an additional three similar cars to be built to Stinger specifications, but with the AIR injection system to meet California emissions laws, with Yenko's permission. A total of 185 Stingers are believed to have been built, the last being YS-9700 built for Goodyear Tire and Rubber Company as a tire test vehicle in 1969 – 1970.

Comedian, television star, and car enthusiast Tim Allen currently owns and races Yenko Stinger #YS-043.

Chevrolet Corvair - John Fitch Corvair Sprint

Longtime roadracer John Fitch was particularly interested in the Corvair as the basis for a spirited road and track oriented car, due to its handling. The basic Sprint received only minor modifications to the engine, bringing it to 155 horsepower (116 kW), but upgrades to the shock absorbers and springs, adjustments to the wheel alignment, quicker steering ratio, alloy wheels, metallic brake linings, the obligatory wood-rimmed steering wheel (leather available for an additional $9.95) and other such minor alterations made it extremely competitive with European sports cars costing much more. Body options such as spoilers were available, but the most visually remarkable option was the "Ventop", a fiberglass overlay for the C-pillars and rear of the roof that gave the car a "flying buttress" profile.

Fitch went on to design and build a prototype of the Fitch Phoenix, a Corvair-based two-seat sports car, superficially resembling a smaller version of the Mako Shark based Corvette. With a total weight of 1,950 pounds (885 kg), even with a steel body, and with the Corvair engine modified with Weber carburetors to deliver 175 horsepower (130 kW), the car delivered spirited performance for $8,760. Unfortunately, the Traffic Safety Act of 1966 placed restrictions on the ability to produce automobiles on a small scale; this was followed by Chevrolet's decision to terminate production of the Corvair, which confirmed the end of Fitch's plan. He still retains the prototype however, and occasionally exhibits it at car shows.

Chevrolet Corvair - V8 Corvairs

The ultimate Corvair modification was replacement of the engine with a V8. As daunting as this might seem, two things made it possible:

1. The Corvair engine rotated in the opposite direction from most other engines, so that if a V8 was placed in the rear seat area (the added weight of a V8 in the original location of the Corvair engine would be abominable to drive), and the transaxle was rotated 180 degrees to meet it, the gearing would drive the car in the proper direction, not four speeds in reverse and one forward
2. The switch in 1966 to using standard Chevrolet Saginaw gear sets in the manual transmission could handle the torque of a V8.

A radiator occupies the former trunk, in the front of the vehicle. However, the former engine compartment in the rear now is available as luggage space. A complete kit to adapt a Chevrolet small-block V8 to a Corvair was manufactured by a company named Crown Manufacturing, for $600. The resulting vehicle weighed only 2,750 pounds (1250 kg), compared to 3,700 pounds (1680 kg) for a small block Corvette, and possessed independent rear suspension of almost the same design. Crown's prototype with 350 horsepower (261 kW) Corvette engine recorded an elapsed time of 12.22 seconds and 105 miles per hour (169 km/h) in the quarter mile (402 m). An advantage of this modification is that the rearward weight distribution gives excellent traction without the need for slick or "cheater slick" tires, let alone modifying the wheelbase as on the FX cars of the time The mid-engine design also provides optimal handling characteristics. Although a few Corvairs have been modified to accept the Chevrolet big-block engine, the added size of the engine makes the work significantly more difficult, and the result, although a great performer, tends to be unreliable.

Adapted from the Wikipedia article "Modifications", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki