The year 1971 was the beginning of a long dry spell for performance enthusiasts. The petroleum industry was busy switching over to unleaded gasoline, forcing automakers to drop compression ratios and slashing the output of many of their top performance engines. The following year, GM stopped posting "gross" horsepower ratings and began using more-realistic "net" numbers. Although the switch in ratings methodologies had no effect on engine output, it did serve to amplify the perception that automotive performance was in a tailspin.
Fortunately, recent advances in engine technology have allowed modern net-power ratings to approach-and, in some cases, even exceed-the gross ratings of the musclecar era. High performance is back in a big way, and the future has never looked brighter.
'85 350 "Tuned-Port Injection" Small -Block L98 (230 hp)Unveiled in March 1983, the long-awaited C4 Corvette paired a world-class chassis design with the rather primitive "Cross-Fire Injection" engine used in the previous model. Fortunately for Vette enthusiasts, help was on the way. The "Tuned Port Injection" (TPI) L98, introduced for 1985, proved superior to its predecessor in every way. Output was up by 25 hp, torque was up by 40 lb-ft, and gas mileage increased 11 percent. The L98 served as the Corvette's base powerplant through 1991, receiving incremental improvements along the way. During that time, Corvettes dominated Showroom Stock racing to such an extent that the model-specific Corvette Challenge series was created.
Displacement: 350 ci
Horsepower: 230 @ 4,000 rpm (1,985 net)
Torque: 330 lb-ft @ 3,200 rpm
Component materials: Cast-iron block and heads, hypereutectic-aluminum pistons, aluminum intake
Induction: Electronic fuel injection
Exhaust: Cast-iron manifolds, dual exhaust pipes
Years offered: '85 to '91
'71 454 Big-Block LS6Between the delayed availability of Chevrolet cars in 1970 and the confusion over the "on paper only" 465hp LS7, the new 454 seemed destined for legendary status. Chevy helped fuel the engine's mystique by bringing a drag-prepped 454 Corvette to a preproduction press event in the summer of 1969. Equipped with a Turbo 400 transmission, open headers, and 10-inch slicks, the car clicked off high-10-second quarter-mile runs . . . until someone broke the motor.
Displacement: 454 ci
Horsepower: 425 @ 5,200 rpm (gross)
Torque: 474 lb-ft @ 4,000 rpm
Component materials: Cast-iron block and heads, forged-aluminum pistons, aluminum intake
Induction: Single four-barrel Holley carburetor
Exhaust: Cast-iron manifolds, dual exhaust pipes with optional side exits
Year offered: '71