1996 Chevrolet Corvette Grand Sport Tested: C4 Swan Song

From the January 1996 issue of Car and Driver.

You could see this Corvette coming a mile away, and not just because of its retina-ripping red, white, and blue paint.

The idea apparently was to take a Corvette in the last year of its model run and turn out a special edition to hook a few customers waiting for next year’s new model. This tactic worked with the pre­vious-generation Corvette, which begat a “Collector Edition” in 1982 with special paint, badges, and wheels and an engine (codenamed L83) closely related to that of the new-design Corvette due the following year. That ’82 car was the most expensive Corvette to date, yet it accounted for a quarter of the year’s Corvette sales.

So here comes the 1996 Corvette Grand Sport, with special paint stripes, badges, and wheels and a new LT4 5.7-liter V-8, reported to be a preview of the Gen III 5.7-liter that will bow in next year’s entirely new Corvette. Surprise!

The Grand Sport is joined by another collector edition, cleverly named the “Collector Edition.” They share chrome badging and the revised V-8, but only the Grand Sport receives the white stripe over Admiral Blue paint reminiscent of the original Grand Sport. That was the name applied in 1962 to five blindingly fast lightweight Corvettes built to take on Car­roll Shelby’s factory-prepared Cobras, right before GM brass slammed the lid on factory racing.

Stay with us here. The Grand Sport is a factory option package for both coupes and roadsters, and about 1000 will be produced. For $3575 more than the Corvette coupe’s $38,120 base price, buyers get the Admiral’s paint job, chrome emblems, leather seats in black or red, and larger tires and wheels (painted black) from the ZR-1. Convertibles get standard-sized tires and wheels. The ZR-1 covered its extra-wide rear 315/35ZR-17 Eagle GS-Cs with three inches of wider fender, but the Grand Sport coupe must do with less expensive but clumsier-looking add-on fender flares (borrowed from Japan-bound Corvettes). This package comes only with a six-­speed manual, which means you must also buy the $1595 LT4 engine, an option shotgun wedding on all six-speed Corvettes this year. (Automatics come only with last year’s LT1.) The LT4 engine, garnished in bright red paint and ignition wires for Grand Sport duty, is an LT1 with throat surgery for better breathing. The cylinder heads have revised ports with wider passages, and valve diameters have been increased by 0.05 inch. Reduced valve-pocket depth on the cast-aluminum pistons raise the compression ratio from 10.4 to 10.8:1. Hollow valve stems, higher-rate springs, and a camshaft profile with higher lift and more overlap allow a 600-rpm redline vault to 6300 rpm.

Finished off with higher-flow fuel injectors, stronger head gas­kets, and a stronger crankshaft, the V-8 reportedly turns out 30 hp more (for 330 total), and at higher rpm—5800, versus 5000 for the LT1. Torque rises by only 5 pound-feet (to 340), but it peaks 900 rpm higher, at 4500 rpm.

Well, yahoo! Bigger tires and more engine! But then we went to the track, where our performance expectations wilted like a Nutty Buddy dropped on hot pavement. The fatter Eagle GS-Cs and revised torque curve make the Grand Sport harder to launch, requiring more revs­—over 4000, versus 2300 for last year’s Vette. Even with that drama behind us, the LT4’s heavier breathing remained elusive. The Grand Sport’s sprint times match those of the last LT1 Corvette we tested—­same 5.1-second 0 to 60, same 13.7-second quarter-mile. Only its 168-mph top speed (a 7-mph improvement) reveals the LT4’s added muscle.

But don’t try this test at home, kids. The Grand Sport option doesn’t buy the LT4 a much-needed oil cooler, and a minute or two at top speed spikes the oil-tempera­ture gauge needle past its red zone. “That’s where the synthetic oil saves you,” says Corvette Engineering Manager Bob Applegate, referring to the Corvette’s Mobil 1 oil recommendation.

At speeds less likely to re-refine the Mobil 1, the LT4 engine delivers the same instant throttle response and vigorous thrust as the LT1, all the way up to its higher redline. No bitching here. The higher revs make the Vette feel more sophisticated, and its characteristic trans­mission whining sounds more purposeful.

Back to those rear tires, which keep the rear end very well planted—perhaps too well. They increase understeer in normal maneuvers. Break the tail end loose with brakes or throttle, on the other hand, and the resulting oversteer is more difficult to manage, especially on less-than-perfect pavement. Our test car’s Z51 Performance Handling package, a $350 spine-pulver­izing collection of stiffer springs and shocks for autocrossers, seems to exacer­bate these tendencies. The silver lining is an increase in cornering grip by 0.04 g, to 0.89 g, and a slight shortening of 70-to-0-mph braking distance, to 164 feet. These numbers are within the range of the Nissan 300ZX Turbo and the Mitsubishi 3000GT VR4, the Corvette’s only competitors now that rigorous OBD II regulations helped excise the manual Toyota Supra Turbo and the Mazda RX-7 from the U.S. market.

If better performance doesn’t distin­guish the Grand Sport, there’s always that graphics package. Behold what you will, but the look demands attention. The optional red seats are so bright they could fuse corneal rods and cones.

Underneath the flash and dash remains a fourth-generation Corvette in its final year. Which carries implications both good and not-so-good. Good is the Vette’s steadily improved quality, drivability, and power, its brute-force sparkle, and its vibrant character. Not so good is this car’s difficult ingress/egress and cramped cockpit, its GM parts-bin feel, its trembly body, and its nervous handling over bumps.

The Grand Sport’s collectibility may render those complaints inconsequential. For enthusiasts who don’t take the GS bait, well, they won’t have long to wait for a fresh catch.

Source: Reviews - aranddriver.com