Idaho Corvette Page


Copyright 1996, Hib Halverson

My last driving impression and some memories of the '84-'96 Corvette.

'96 Grand Sport

by Hib Halverson

          My God. Has it been 14 years?

In December of 1982, when the new Corvette was shown to the press, I didn't have a full-time media job. Back then on weekends, I volunteered as a firefighter with the Sports Car Club of America's rescue crew at old Riverside International Raceway. I came out to work a club race and heard from track employees that Chevrolet had rented the place during the week for the press preview of what engineers called "the 83Y." They described some kind of super car with smoother looks, more speed, incredible handing and some kind of digital dashboard out of a jet fighter. I remember listening to their description in partial disbelief. I probably replied something like, "Whoa, dude are you sure? No way can a car be like that."

In June of 1983, I landed my first real car magazine job and, early the following year, I wrote my first article about the '84. While I had been a Corvette owner since 1969, the only generation of the car in production during my magazine career has been C4 and I've come to know it very well. I've driven at least three dozen of them since then and I remember many milestones. Obviously, one was the '84. Then came the Tuned-Port-Injected, 150 mile-per hour '85. The following year ABS arrived and the Roadster returned. A roller-lifter engine came in '87 and '88 saw a major suspension revision. We got the wonderful six-speed and Selective Ride Control in '89. Of course, 1990 brought the legendary King-of-the-Hill Corvette, the ZR-1, and its incredible LT5 DOHC V8.

Memory 1

In 1991, the outstanding Z07 suspension was offered. In 1992, we got the Gen2 300hp, LT1 Small-Block which, from an engineering standpoint, was nearly the masterpiece the LT5 was. The ZR-1 went to 405hp in 1993 and that may very well have been the high-water-mark for a medium-displacement engine in a Corvette. The introduction of Goodyear GS-C EMTs in 1994 marked the first use of a run-flat tire on any production car. The last great C4 milestone came this year in the form of the LT4 engine.

In 12 model years of production, C4 has aged; however, buyers continue to consider it the benchmark for performance sports cars. In the last decade, Corvette sales remained stable while that of others in the high sports market segment have plummeted. In some cases, Corvette has driven competitors, (Nissan 300ZX, discontinued halfway though the 1996 model year, and Mazda RX7, ended production in 1995) out of the market. While the overall size of the high sports segment has shrunk, Corvette's share of it, as of 8/96, had grown to an amazing 39%.

Looming on the horizon may be stiffer competition for America's Sports Car in the form of: through sharp marketing, improved product and wider range of models, the Dodge Viper; with a manual transmission available again, the Toyota Supra Twin-Turbo and, the first affordable model from Zuffenhausen in many years, the Porsche Boxster. Corvette has new challenges ahead that will be met by the C5. Our mandate here, though, is a look back.

Ninety-six was an eclectic model year for Corvette. Take the Grand Sport. Wow, now there's visual impact! Only 976 were built. The option was mostly show-Admiral Blue with a white stripe, black wheels and a set of red hash marks on the left front fender. Intended to recall the look of the late Zora Duntov's lightweight race cars of the 1960s, the Grand Sport cut a strong profile you either liked or didn't.

We had the GS in these photos for a week and, early one morning I took a look at the car and wished I had drunk two cups of coffee, first. Other times, I was enamored with the white stripe on blue for its ability to turn heads and be distinctive amongst other C4s.

Everyone associates Corvettes with powerful engines. Be it FI motors, big-blocks, the old LT1 or the new LT1, the Corvette has almost always had a great engine. I can remember at least three media programs I have attended in my career that centered around Corvette engines.

Memory 2

It's no surprise that the best option of 1996 was the LT4 Small-Block V8. It came only with the ZF S6-40 six-speed manual transmission and was available on any '96. LT4 owes its existence to the C5's LS1 Gen3 V8. The early Gen3 was yet another iteration of the veteran Small-block; however, it eventually became apparent that no Small-Block could meet the C5's powertrain goals and, some time in 1992, Gen3 became an all new engine and existing work was finessed into the LT4.

The upgrade pieces were: a nodular-iron crankshaft with rolled-fillet journals, freer-flowing cylinder heads, higher tension valve springs, a roller timing chain, larger valves with hollow-stems, 1.6:1 aluminum roller rocker arms, higher capacity fuel injectors and the PCM calibration to go with all this. The changes were worth 30 horsepower and about 800 more usable rpm.

LT4 is a kick to drive. It feels much like an LT1 up to about 5000 rpm, but runs hard beyond that. On the dragstrip, in a Collector Edition (CE) Coupe, LT4 showed its stuff by going 13.34/107.2 in my tests. This engine will go down in history as the most powerful production small-block V8 ever put in a Chevrolet. Before you e-mail us about the original LT1 and the 375hp FI motors, remember, they were rated with the gross power system in use until 1972. Since then, engines have been rated with "SAE net" power. It is possible to compare and, if the LT4 was tested using the old system; it might have been rated at about 380-390 hp.

LT4 also had two sobering down sides. Rocker arm failures caused by roller tip pins falling out developed into a full-blown fiasco with two recalls during 1996 of a large number LT4s. The initial fix did not solve the problem, so the second recall affected all the cars of the first. Is that, like a "re-recall"? OK, just kidding.

I know customers told not to drive their LT4s because of an initial shortage of recall repair parts saw little humor in that situation. GM eventually fixed all the sick-rockered LT4s at no charge. Those and the ones built after the solution was found, were quite reliable.

The other problem is something 99% of LT4s will never experience. However, anyone that road races or time trials a '96 with that engine, especially those with suspensions modified for better handling, ought to beware. A source at GM told us that because of crankcase windage above 5500 rpm and the rate of oil drain-back, when an LT4 experiences sustained, high lateral acceleration; the oil level may get low enough for the pump to suck air. We have no test data to support this, but our advice to road racers is: don't gamble. When you go to the track; add half a quart or so of extra oil. If you don't road race, don't worry about it and *do not* add extra oil for street use. In spite of the rocker recall and potential race track oiling problem, the LT4 is a very stout performer, a small-block I liked a lot and, obviously, the best of the last.

The other gearhead story in 1996 was RPO F45, the Real Time Damping or "RTD" system. Like Selective Ride Control (SRC) that preceeded it, RTD is "ride-adaptive" shock absorbers that vary their valving and a computer to control them. However, unlike SRC, which set damping according to vehicle speed, RTD uses real-time body motion as the input the controller uses to determine shock settings.

SRC shocks used electric motors to change valving and were incapable of doing that at the speed necessary for real-time operation. RTD shocks use a faster, bi-state solenoid valve which makes real-time operation possible. This speed even allows the controller to set different valving at each shock on a momentary basis which better damps corkscrew body motions. User input was by the familiar three-position selector. In "sport" the shocks switch to firm more often than when the system is in "tour". In "performance," the shocks are locked in firm.

During 1996, I subjectively tested F45 in two different cars. During those tests I was unimpressed with Real Time Damping, especially considering its $1695 price tag. RTD lacks damping bandwidth. The soft setting was not soft enough in some situations and the firm setting seemed to lack damping in certain aggressive driving settings. We suspect two reasons for this:

1. Bi-state operation limits the system's benefits.

2. The C4 structure may have insufficient torsional rigidity for effective application of RTD
when different valving is commanded at each corner of the car

My subjective evaluations, also had me feeling that, during low-frequency body motion with the system in "tour" mode, RTD sometimes unnecessarily switched to firm valving. When performance handling was tested, both RTD cars I tried came up a little short. They understeered a bit too much at the limit, they seemed softly sprung and their transient response was not as crisp as I would have liked. In the end, I believe the option did little to improve performance handling and its impact on ride was less than I had expected. RTD, while technically innovative, was a questionable value to the Corvette customer.

C5's torsional rigidity will be 450% more than that of C4. It also will have, as an option, the continuously variable and increased bandwidth version of RTD, currently used on some Cadillacs. Base on my testing of pilot versions of C5 at Road Atlanta last month, I can say confidently that the combination of increased rigidity and CV/RTD will finally offer the Corvette customer real-time damping with value and utility that exceeds that of the old SRC.

The performance suspension option for 1996 was Z51; however, don't confuse it with the same RPO number from the 1985-'90 period. The "new" Z51 is an excellent suspension package for high-speed touring, even on rough roads, a place the old Z51 was pretty rough riding. Its spring rates are nearly identical to those of the '92-'95 ZR-1s, it used base car stabilizer bars and a set of 275/40ZR17 GS-Cs. Grand Sports with Z51, got 315/35ZR17s on the rear. Compared to '96 base and F45 suspensions, understeer was less and transient response was slightly better. Also, by virtue of a new set of fixed-valve, Delco-Bilstein shocks, Z51s had excellent wheel control in an aggressive touring environment.

The C4's last year was the first time since 1984 that there was no suspension option for those on the fringe of the car's demographics, the aggressive street drivers, autocrossers, time trialers and amateur road racers. With ZR-1-like wheel rates, a '96 Z51 seemed to us to be a bit out of its element on some race tracks with a bit much body roll and transient response maybe a teensy bit slow. Autocrossers who tried '96s longed for the stiff and crisp feeling Z07s and Z51s of past years.

Memory 3

The marketing staff deep, deep inside GM might think, "Well, Halverson is blowing smoke. Racers are a tiny minority of our target customer base. So what if a suspension option for them isn't part of our plan? We save money and have less parts in the assembly plant." Think again. While aggressive drivers and grassroots racers are perhaps the lunatic fringe of the group that buys America's Sports Car; they are some of the strongest proponents of the Corvette Mystique. Word of mouth is a major factor in marketing an automobile.

The C5 will offer a Z51 suspension consisting of more aggressive springs and stabilizer bars along with a set of fixed-valve shocks. It proved to be pretty damn good in my brief test at Road Atlanta however, I will reserve my final assessment until I test a production version more extensively. Traditionally, the aggressive suspension option has always gotten softer after a platform change. I hope those that control the C5's destiny will always remember that the car needs to cater to the lunatic fringe.

Build quality.
There is a phrase that gets a Corvette assembly plant manager's pulse racing. Because the C4 was complex to assemble and one of GM's most elaborate technical exercises, build quality was a perplexing issue throughout the platform's tenure. In the early years, quality was a problem. In the '90s, sparked by the influence of former Chevrolet General Manager, Jim Perkins, there was concerted effort to upgrade quality. By 1995 this had paid off with marked improvement, but there were still inconsistencies.

There were both yays and nays in our subjective assessment of quality for 1996. The Collector Edition Coupe we drove was a wonderful car and a perfect example of how well Bowling Green can screw together Corvettes. The engine ran like a bat out of hell. The ZF shifted smooth as a hot knife through butter. The rear axle, long a sticky quality issue, was silent. The car made nary a squeak or rattle and interior/exterior fit and finish were excellent. That gorgeous Sebring Silver paint my goodness, it was flawless and clear evidence that the BG paint shop's switch from solvent-borne to water-borne base coat was an outstanding improvement.

One evening last summer, we took the CE to cruise night at Frisco's Drive-In in Industry, California. Besides great burgers, fries and shakes, Frisco's is one of the few places with carhop service on cruise nights and all the waitresses are on roller skates. While the Collector Edition didn't catch quite as many eyes as a Grand Sport might, it looked so beautiful parked in front of the restaurant that we almost saw it hijacked by a dozen 'Vette-struck, Frisco Girls.

The two Grand Sports we drove were another story. The first one, which we had for a week last February, leaked past both side windows. It had a rattle in the rear suspension and the engine made a tic-tic-tic noise that gave us rocker arm nightmares. The second GS, which we drove for a week before this article was written in September of '96, was privately-owned rather than being a media fleet vehicle. The paint on this car was, well awful. In several places the white and blue had overspray of the opposite color. The Admiral Blue on the doors and the right rear quarter did not match the same color on the rest of the car and the blue on the hood was blotched. Neither of these cars were Bowling Green's best foot forward, I am afraid.

In summary, 1996 was a mixed-bag for the Corvette. The best of the last was, without a doubt, the outstanding LT4/six-speed powertrain and the tasteful, classic appearance of the Collector Editions. The worst of the last was the expensive RTD shocks and inconsistent build quality.

I get asked a lot what I think was the best C4. My answer? A close contest between a '94 Z07 and a '95 ZR-1. In four road trips in the last two years, I drove them a total of 17,000 miles.

Memory 4

The best C4? Well, I can't decide, so I declare a tie between any '92-'95 Z07, six-speed and any '94 or '95 ZR-1. Why a tie? Z07, manuals can't quite pull off a win because they don't have the wonderful LT5 or the cool, five-spoke wheels. The last ZR-1s can't quite grab the win because they don't have the Z07's crisp handling. Now, what if we were to fit a ZR-1 with the Z07's suspension parts? Whoa what a concept!

For me, the C4's recession into history is bittersweet. Bitter because my writing career to date has developed around it and I am sad to see it go. Bitter because some friends I made at Corvette Development during the late-'80s/early-'90s are gone. Current GM policy seems to discourage close relationships with media, so the ones that remain are more inaccessible and, in some cases, reluctant to communicate as freely as in the past.

Bitter because C4 goes away at a time when GM seems less aware of the emotion and mystique surrounding the Chevrolet Corvette and more attentive to head count reduction, mission statements, media control and truck sales. In recent years, GM appears to have forgotten part of how to market Corvettes in a manner that keeps in touch with the car's heritage and enthusiast base. Recent evidence came last June with the inadequate recognition of the last C4. The World Record run of 1990 is one of the most historic achievements in the car's more than four decades of production. Yet, in the "History" section of the *1996 Chevrolet Product Information Guide*, the book most media depend on, the World Records aren't mentioned. We hear through the grapevine of the Corvette hobby that there is discontent over Chevrolet not responding to the highly successful marketing of the Viper as Chrysler's flagship. Clearly, GM looks at a 39% market share with tremendous confidence.

Sweet because, admittedly, C4 is past its prime. The car has some significant weaknesses-structure, rear suspension, complex assembly-and C5's new technology will address those issues. It's past time for a new Corvette which I await with frenzied anticipation.

Sweet because the departure of the old platform and the excitement surrounding the new gives GM the perfect opportunity to reestablish its perspective of the car's mystique, heritage and enthusiast base. I sincerely hope that Chevrolet's withdrawal of factory support for SCCA Trans-Am teams this year means significant factory support for a major Corvette effort at Le Mans in 1998.

Sweet because what is in the tube for 1997 and through the next millennium is going to be another great Corvette.

-Hib Halverson

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