From the Archive: 1993 Chevrolet Corvette ZR-1 Test

From the May 1993 challenge of Car and Driver.

Travelers out west are acquainted with indicators that warn “DO NOT DRIVE INTO SMOKE.” One of those indicators needs to be bolted to the convex fiberglass rump of the 1993 ZR-1. At least whilst you’re conducting 0-to-60 accel assessments—purely within the identify of science, in fact—with the traction management disengaged. I imply, you would not assume that any engine wanting one thing concocted by John Force may so immediately rework two twelve-inch strips of gooey Eagle GS­-C right into a dense and acrid wall of smoke the colour of Flint Ink’s Butterfinger blue. But that is what 405 horsepower can do for you. Also, that is what 405 horsepower can do to your insurance coverage agent’s complexion.

But by no means thoughts that. The huge information is that the ZR-1 lastly provides the ability it ought to have generated when the engine was launched in 1989. Jim Minneker, the Corvette Group’s powertrain supervisor, and the folks at MerCruiser in Stillwater, Oklahoma, have extracted one other 30 horsepressure, elevating the ante to 405, a determine that at all times evokes a pant and a “Holy smokes!” or two when it’s divulged to onlookers. (If that does not do it, point out casually that second gear is nice for 84 mph.) Torque is up, too, however by solely 15 pound-feet, elevating the rely to a not-insubstantial 385 pound-feet at 5200 rpm.

Twenty of these horses have been obtained when the plenum and the consumption runners have been polished and, as Minneker says, “generally opened up.” Moreover, says an insider, “finally a little bit of porting and matching is going on—so few ZR-1s are being sold [4600 to date] that there’s time.” The valve inserts now have what is named a “three-face cut” for much less turbulent air/gas stream—a trick plagiarized from hot-rodders with black gunk completely clogged underneath their fingernails. And a brand new spacer ensures nearer alignment of the ports and the injector manifold itself. In addition, the LT5 is crammed with platinum-­tipped plugs, that are hotter than final 12 months’s, and the engine glides solely on artificial Mobil 1.

The remaining 10 hp, says Minneker, resulted from a discount in backpressure. GM appears a bit embarrassed by this, however the 2.25-inch tubes within the resonators of final 12 months’s LT1 have been flowing extra freely than the 1.75-inch variations strapped to the ZR-1. The King of the Hill now wears its much less beastly brother’s resonators and breathe a bit simpler within the cut price.

C/D readers might recall that our favourite Corvette aftermarket fiddler, John Lingenfelter, went by way of the identical ZR-1 cleanup program, maybe extra rigorously, in July of 1991. He got here up with a bonus of 80 horsepower, bringing the full to “an easy 455.” Since then, he says, “I’ve worked harder and am seeing as much as 485 horsepower. There’s a ton of untapped potential in a ZR-1.” (If you need extra of this untapped stuff, drive your ZR-1 to Lingenfelter’s in Decatur, Indiana, and hand him $13,500.)

In any occasion, the new-and-improved 1993 ZR-1 is each bit as docile round city as final 12 months’s, which is to say it’s like driving another present Corvette. In truth, we’re now even much less conscious of the secondary inlet port banging open. What’s extra, in the midst of this check, the firmament over Michigan divested itself of six inches of snow, slush, and ice. You would not count on tires that look as if they have been stolen from Steve Kinser’s dash automobile to work on an ice rink. But after they’re mixed with the Corvette’s efficient traction management (whose technical, however ridiculous, identify is “Acceleration Slip Regulation”), the ZR-1 does in addition to a 405-horsepower Zamboni. Trust us, it is a declare that can’t be made for both a Mazda RX-7 or a Toyota MR2 Turbo.

So how briskly is 405 horsepower on dry pavement?

With a smoke-warning signal hanging on the ZR-1’s tail, 60 mph is yours in 4.7 seconds. (The first ZR-1 we ever examined hit 60 in 4.6 seconds, although that is largely testimony to the unpredictable tolerance with which MerCruiser tended to assemble engines. Two subsequent ZR-1s tackled 60 in an similar 4.9 seconds—a determine we accepted because the norm.)

The 1993 ZR-1 carries on by way of the quarter-mile in 13.1 seconds at 111 mph, then ultimately attains 179 mph—6 mph past the common high velocity of earlier ZR-1s. On the way in which there, the massive inch-­excessive speedometer digits flick previous like bicycle spokes fanning a baseball card. Not in particular person items however in clumps: 3 mph right here, 5 mph there. Skidpad grip is up, too, from a previous ZR-1 common of 0.88 g to a leech-like 0.92 g. Thank you, Mr. Goodyear.

In truth, the 1993 ZR-1’s accelerative résumé, all the way in which from the 7-Eleven lot to high velocity, is nearly similar to the limited-production Porsche 911 Turbo S2’s—”the fastest Porsche in the land.” Which, we should always level out, is dearer by an quantity that lets you buy each this ZR-1 and, say, a Lexus GS300 for these days when solely Interstating is on the menu.

The new ZR-1’s velocity makes even General Motors fidget. On its official spec sheet, underneath the “Performance” heading, Chevrolet lists EPA mileage and drag coefficient (0.33, should you’re questioning), then strikes proper on, uttering nary a touch that this automobile surpasses the best U.S.-legal velocity by, ah, 114 mph.

To nail 60 mph sooner and fewer expensively, you will have to purchase a $35,660 LT1 and haul it to Lingenfelter, who’ll lay his magical smog-legal “383 Kit” on the factor. This will increase your funding to $50,000 however will launch you to 60 mph a half-second earlier than a ZR-1 can. Which has nothing to do with manufacturing vehicles, in fact, however neither does Detroit Mayor Coleman Young, a subject that comes up in dialog nearly as usually.

We’ve come to count on eyeball-popping brakes on Corvettes. The new ZR-1, with its frying-pan thirteen-inch entrance rotors, doesn’t disappoint. No kidding: from 70 mph, should you dropkick the Bosch ABS IIU into most seize, it is like some type of amusement-park journey. Loose objects slam into the sprint, the passenger’s seatback lunges a half-inch, your ears really feel as if they could fold ahead and canopy your eyes, and the automobile involves relaxation in 161 ft. Some feat for a 3500-pounder. Eight ft higher than a Ferrari 512TR, actually. To recurrently equal this type of braking, shift your posterior and pockets to vehicles assembled in Zuffenhausen—which, as everyone knows, just isn’t as simple to pronounce as Bowling Green.

The ZR-1 you see right here was kitted out with a fortieth Anniversary package deal, which you’ll be able to order on any Corvette (assuming you’ve got an additional $1455 earmarked for common way of life enhancement, though it is a no-cost choice on the ZR-1). The deal consists of unique “Ruby Red” metallic paint, matching wheel hubs, 4 chrome emblems (with which we may gladly dispense), particular embroidery on every headrest (proper the place it will get smeared by Vitalis), and Ruby Red leather-based seats.

Okay, okay. The ZR-1’s clutch continues to be Caterpillar heavy, and the computer-assisted shift that happens at low speeds to drive a first-to-fourth choice continues to be an irritating intrusion. Also, nobody can distinguish your stylish ZR-1 from Billy Ray’s base LT1, the doorsill stays a hurdle plucked proper from a 100-meter occasion, the bar-graph gas gauge is as simply discernible as a 1040 type, the hood nonetheless goes all epileptic over railroad tracks, and, at solely 3200 miles, our ZR-1’s glovebox door mimicked the sound of Leona Helmsley’s fingernails dragging throughout a blackboard.

Yet, as our editor, Csaba Csere—a person who poses questions that will embarrass Larry King—put it: “Name another production car this reliable and cheap that you could drive as happily at 179 mph.”

Apart from the toe of my shoe carving fascinating Rorschach patterns within the workplace carpet, there was silence.

The Latest in Door-Locking Magic

Power locks have change into widespread­place, and remote-control unlock­ing units have misplaced their zoot. Now, Chevrolet introduces the newest factor in trick openers—the world’s first Passive Keyless Entry system (PKE). It is now attainable to run by way of a blizzard, arms filled with groceries and mittens on fingers, and have your Corvette magically unlock itself as you method.

Here’s the way it works. Step inside about six ft of the automobile whereas carrying your keys—even in a pocket or a handbag—and the system disarms the alarm and unlocks both the motive force’s door or each doorways, relying on the mode you’ve got chosen. To lock up, simply stroll out of that vary; 5 seconds later the automobile locks, rearms the alarm, and confirms the maneuver with a single toot of the horn (except the important thing has been left within the ignition).

The {hardware} behind this magic features a transmitter in the important thing fob that broadcasts a really low frequency sign—120 kHz, versus 300 MHz for the standard distant entry system—to 2 antennas, one positioned within the driver’s door and one close to the rear hatch (or passenger door in a convert­ible). One million transmitter codes guarantee safety. When the transmitter in the important thing fob comes into vary, it acti­vates the system by finishing an elec­tromagnetic discipline, considerably just like the coupling of two windings in a trans­former. So PKE is fully totally different than at the moment’s radio or infrared distant programs.

To lengthen its battery life, the important thing fob solely transmits a sign whereas in movement, which may trigger an issue for individuals who go away keys sitting on a seat within the automobile. When the transmitter shuts off (after 30 seconds with out movement), the automobile presumes it’s out of vary and locks the automobile. With luck, jiggling the automobile can reactivate the transmitter and unlock the doorways, however Chevy warns in opposition to counting on this method.

The PKE attracts about one milliamp of present from the automobile battery always—about as a lot because the clock and the radio station preset reminiscence draw—so Chevy recommends that you simply disconnect the battery earlier than storing the automobile for lengthy durations.

There aren’t any present plans to increase PKE to different fashions. But as a result of the system provides appreciable comfort for about $145, we count on it to go the way in which of energy locks and wind up within the majority of high-line vehicles. —Frank Markus