C4 FACTS This page contains year by year changes, information, facts and specs for the C4 Corvette. If anyone finds any errors, mistakes, or has some other interesting fatcs to add then please email them to me. Scroll throught the years or click below to go to a specific year.
1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996
Production: 51,547 coupes.
VIN Ranges: 1G1AY0782E5100001 thru 1G1AY0782E5151547
The 1984 Corvette was a complete redesign in almost every aspect. Handling considerations dominated and the result was praised by the motoring press as the world's best cornering automobile.
The 1984 Corvette was introduced in March 1983. Because it met all 1984 federal requirements, Chevrolet decided to skip the 1983 model designation. The result was a very long production run and the second highest model year volume in the Corvette's history. 1983 Corvettes were built, serial numbered, and tested by both Chevrolet and the motoring press at the "long lead" preview at Riverside Raceway in December 1982. But 1983 Corvettes were not released for public sale.
Design criteria specified that the 1984 Corvette have more ground clearance and more interior room, but less overall height. In order to achieve it, engineers routed the exhaust system through the centretunnel.
A "4+3", 4-speed manual transmission, built by Doug Nash, had overdrives in the top three gears for improved fuel economy.
All 1984 Corvettes were designed with one-piece, lift-off roof panels and rear hatch windows. At the time, the rear window glass was the largest compound glass ever installed in an American automobile. The front windshield was raked at the greatest angle, 64%.
Brakes remained disc at all four wheels, but components were new and included aluminum calipers supplied by Girlock of Australia.
Electronic instrumentation was standard and included digital readouts for engine monitoring and liquid crystal graphic displays for speed and engine revolutions. Analog instrumentation was not available.
The 1984 Corvette was designed with a pad protruding from the passenger side of the dash. This was part of a passive restraint system conceived when it was assumed the federal regulation would require such restraints. The Reagan Administration dropped the restraint proposals, but the Corvette's pad remained.
The 1984 Corvette was designed without fiberglass seams on exposed panels to eliminate factory finishing. The exterior seams were under the rub strip extending around the entyre body.
The radiator was a new design using aluminum for the cooling fins and plastic for the reservoirs. A thermostatically controlled electric fan operates only when needed and only under 35mph. The fan cut in when engine coolant temperatures reached approx 227-228 degrees F (110 deg Celcius).
Chevrolet built specially modified 1984 Corvettes for the export markets of European, Middle East, Japanese, and Latin American countries. Changes included different license plate provisions, leaded fuel capability, and electrical, glass, lighting and mirror modifications.
Single transverse plastic leaf springs were used front and rear.
A 350ci, 205hp engine, 4-speed automatic transmission, removable body-colour roof panel, and cloth seats were included in the base price.
Optional leather seats were the same design as the base cloth style Sport seats were available in cloth (different material than base) and featured inflatable lumbar support and power-adjusted side bolsters.
The RPO QZD 16-inch tyre and wheel package, initially intended to be included as part of the Z51 option, and as a separate option for base models, was required for all 1984 Corvettes sold . The scheduled standard 15-inch alloy wheels and P215/65R15 tyres were not used.
RPO Z51 included heavy-duty front and rear springs, shock absorbers, stabilizer bars and bushings, fast steering ratio, engine oil cooler, extra radiator fan (pusher), P255/50VR16 tyres and directional alloy wheels, 16x8.5-inch front,16x9.5-inch rear.
All wheels were alloy with similar exterior appearance. Base models had all 16x8.5-inch. Z51 models had 16x8.5-inch front, 16x9.5-inch rear.
Road & Track magazine tested the 1984 Corvette to a best time of 7.1 seconds 0-60mph, 15.5 sec @ 88.0 mph 1/4, and a top speed of 137 mph. Braking from 60-0 mph was 112ft.
1985
PRODUCTION: 39,729 coupes 3
VIN: 1G1YY0787F5100001 thru 1G1YY0787F5139729 The 1982 and 1984 Corvette engines had "Cross Fire Injection," but genuine fuel injection returned to the Corvette in 1985 for the first time in two decades. The 1985 tuned-port injection, built by Bosch, was standard equipment and featured a mass airflow sensor, aluminum-tube tuned intake runners, a mold-cast plenum, and an air cleaner mounted forward of the radiator support. This new L98 engine delivered a horsepower increase from 205hp to 230hp, a torque increase from 290 ib.-ft. to 330, and a real-world fuel economy increase of about 11%.
The overdrive selection switch for 4-speed manual transmissions was moved during 1985 production from the console to the gear shift knob.
Suspension rates were lowered in 1985, a result of harsh ride criticism. Springs for the base suspension were softer by 26% in front, 25% in the rear. Springs for RPO Z51 were 16% softer in front and 25% softer in the rear. To compensate forthe spring change, larger-diametrestabilizer bars were Included wnh Z51-equipped models.
in its January 1985 "ten best" issue, Car and Driver magazine pronounced the Corvette to be America's fastest production car at an even 1 50mph top speed. Corvette also took top honours in top-gear acceleration and tied for best (with Porsche) in roadholding as measured by G-force skidpad adhesion.
The bore of the brake master cylinder was increased in 1985, and the booster itself was plastic, the first such application in an American car. The new plastic booster was 30% lighter and less subject to corrosion.
Manual transmission 1 985s came with a new, heavy-duty 8.5-inch ring differential.. Rear axle gearing for manuals was 3.07:1. Standard gearing for automatic transmissions was 2.73:1, but the 3.07:1 could be ordered as RPO G92.
Wheel balance weights changed in 1985 from the outside-rim, clip-on style, to an Inner-surface adhesive type. The change was mainly for aesthetics, but Chevrolet also believed a better balance resulted because of the adhesive weight's proximity to the wheel's depth centre.
A full length oil pan gasket reinforcement was added to the 1985 Corvette engine to improve gasket compression seal.
The 1985 Corvette distributor was modified to prevent distributor spark ignition of exterior fuel vapours.
Electronic instrumentation was revised with cleaner graphics,less colour on the speedo and tacho, and larger digits for the centre cluster liquid crystal display.
Electronic air conditioning was announced as a late 1985 option, but was delayed till the 1986 model.
A 350ci, 230hp engine, 4-speed automatic transmission,
removable body-colour roof panel, and cloth seats were included in the base price. The optional sport seat, available only in cloth for 1984, became available in leather after the start of 1985 production. The total number of leather seats sold was 30,955, but the individual quantities of base leather seats and sport leather seats is not currently available.
RPO Z51 included FG3 Delco-Bilstein shock absorbers, V08 heavy-duty cooling, extra radiator fan (pusher) heavy-duty front and rear springs stabilizers and bushings, fast steering ratio and 16x9.5-inch wheels. FG3 and V08 were available separately with non-Z51 models.
The RPO CC3 removable transparent roof panel was given stronger sun screening for 1985.
A map strap was added to the 1985's drive-side sun visor.
Road & Track magazine tested the 1985 Corvette to a best time of 5.5 seconds 0-60mph, 14.8 sec @ 98.5 mph 1/4, and a top speed of 154 mph. Car & Driver magazine tested the 1985 to a 14.4 sec @ 95 mph 1/4 for a manualised version and a stonkin' 14.1 sec @ 97 mph for the auto. 0 - 60 mph times were 6.0s and 5.7s respectively.
PRODUCTION: 35,109: 27,794 Coupes, 7315 convertibles
VIN: 1G1YY0789G5100001 thru 1G1YY0789G5127794 (coupe)
1G1YY6789G5900001 thru 1G1YY6789G5907315 (conv)
A Corvette convertible model was introduced in interim 1986, the first Chevrolet-built Corvette convertible since the 1975 model. The 1986 Corvette was the pace car for the 1986 Indianapolis 500. All 1986 Corvette convertibles sold were designated as pace car replicas and all included decal packages for dealer or customer installation.
An anti-lock brake system (ABS) became standard with 1986 Corvettes. An adaptation of Bosch's system, Corvette's ABS had rotational sensors at each wheel to feed data to a computerized electronic control unit (ECU) . Brake line pressure was automatically distributed for optimum braking without wheel lock and loss of steering control.
Cracking around the head attachment bosses required an introduction delay for design revisions to 1 986's aluminum cylinder heads The heads were ready in time for convertible production and all 1986 convertibles and late production coupes had aluminum heads. Engines fitted with aluminum heads were rated at 235hp, an increase of 5hp.
Centre high mount stoplights were added to 1986 Corvettes to conform to federal requirements. The coupe's was mounted above the rear window; the convertible's was in a less-conspicuous rear facia location.
A new vehicle anti-theft system (VATS) required a special ignition key with an embedded pellet. Lock cylinder contacts measured the pellet's electrical resistance (there were fifteen variations) before allowing start
Caster was changed in 1986 f rom four degrees to six degrees to improve on-centre road feel and to decrease wander.
Fifty "Malcolm Konner Commemorative Edition" 1986 Corvettes were built In a special arrangement honouring the New Jersey Chevrolet dealership's founder. Malcolm Konner. Each Corvette had special two tone paint schemes, Silver Beige over Black, coded "spec." Window stickers reflected 4001ZA as the RPO, and a $500 cost for MALCOLM KONNER SP. EDIT. PAI. All were coupes, twenty with manual transmissions, thirty wnh automatics. All had graphite leather interiors. One was retrofitted with a Callaway twin-turbo engine
The angle of the 1986 digital instrument display was changed to improve daytime viewing by reducing glare.
A new upshift indicator light for manual and automatic transmission 1986 models was intended to improve fuel economy.
"Low coolant" and "anti-lock" instrument displays were added.
Wheel design was revised slightly for 1986, with the wheel centre section natural finish instead of black as in 1984 and 1985.
A 350ci,230hp (iron cylinder heads) or 235hp (aluminum cylinder heads)
Road & Track magazine tested the 1986 Corvette to a best time of 5.8 seconds 0-60mph, 14.4 sec @ 96.0 mph 1/4, and a top speed of 154 mph. They also tested a Callaway twin turbo of which recorded 0-60mph in 5.0 secs, 1/4 mile in 13.7 secs @ 104 mph.Car & Drive magazine achieved 6.0 sec to 60mph and a 1/4 mile result of 14.5 sec @ 95 mph. (test conducted on convertible)
1987PRODUCTION: 30,632: 20,007 coupes, 10,625 convertibles
VIN: 1G1YY2182H5100001 thru 1G1YY2182H5130632
For conv, 6th digit is a 3.
Friction reduction from roller valve lifters (new for 1987) resulted in a power increase to 240hp, up 5hp from 1 986's aluminum-head engines.
Centre sectons and radial slots of 1987 wheels were painted argent gray 1986 wheel centres were not painted. Centres and radial slots for 1984 and 1985 were painted black.
Convertibles and early coupes had outside mirror air deflectors.
Chevrolet planned an RPO UJ6 low tyre pressure indicator option, but the $325 option was on constraint during 1987 due to false signalling problems. However, Chevrolet records show forty-six units sold.
The RPO Z51 package was refined to include structural enhancements developed for the convertible, and a finned power steering fluid cooler.
A new RPOZ52 "sport" handling package combined elements of Z51 with the softer suspension of base models. RPO Z52 included the radiator boost fan, Bllstein shock absorbers, engine oil cooler, heavy-duty radiator 16x9.5-lnch wheels, faster 13:1 steering ratio, larger front stabilizer bar (except early production), and the convertible-inspired structural improvements for coupes. Z52 was available with coupes or convertibles automatic or manual transmissions.
The overdrive-engage light was moved from the centre-dash area (198486) to an easier-to-view location within the 1987 tach display.
The Callaway Twin-Turbo engine package introduced in 1987 was not a factory-installed option, but could be ordered through participating Chevrolet dealers as RPO B2K. Fully assembled Corvettes were shipped from the Bowling Green Corvette plant to Callaway Engineering in Old Lyme, Connecticut, for engine and other modifications. The 1987 Callaway had ratings of 345hp and 465 Ib.-ft torque, and reached a top speed of 177 9 mph with .60 overdrive gearing. The first four 1987 Callaways used replacement LF5 (truck) shortblocks, but subsequent cars had reworked production Corvette engines. All 1987 Callaways had manual transmissions and none were certified for California sale. Of 184 twin-turbos built In 1987, 121 were coupes, 63 were convertibles.
Electronic airconditioning control (RPO C68) became an available option for coupes and convertibles in 1987; in 1986, it was coupe-only
New 1987 convenience options included an illuminated vanity mirror (D74) for the dnver's visor, and a passenger-side power seat base (AC1). Twin remote heated mirrors became available for convertibles as RPO DL8. The heated mirrors were included with the heated rear window in the RPO Z6A defogger option for coupes.
A 350ci, 240hp engine, 4-speed automatic transmission, removablebody-colour roof panel (coupe) or soft top (convertible), and cloth seats were included in the base price.
RPO Z51 included B4P, FG3, KC4, V01,16x9.5-inch wheels, heavy-duty
suspension, fast steering ratio. Coupes and manual transmissions only.
Road & Track magazine tested the 1984 Corvette to a best time of 6.3 seconds 0-60mph, 14.8 sec @ 95.0 mph 1/4.
Production: 22,789: 15,382 coupe, 7,407 convertible
Vehicle: 1G1YY2182J5100001 thru 1G1YY2182J5122789
For Callaway twin-turbo Chevrolet engine coding was replaced as follows: First two digits for year, next three digits for Callaway sequence last four digits to match last tour digits of vehicle identification number.
Refinements tor 1988 included carpeted door sills, solution-dyed carpet improved "flow through" ventilation for coupes, and a lower, rearward relocation of the parking brake handle.
Engine power remained at 240hp for 1988 models except for coupes with 3.07:1 axle ratios which had 245hp. The 5hp increase came from less restrictive mufflers which were deemed too loud for convertibles and 2.59:1 axle coupes.
A thirty-fifth anniversary edition 1988 Corvette package was available for coupes only. It featured a two-tone exterior of white with black roof bow white leather seats, steering wheel, special interior and exterior accents a console-mounted anniversary plaque, special emblems and other distinguishing features. Sales totalled 2,050 units.
Chevrolet built fifty-six street-legal Corvettes forthe 1988 SCCA Corvette Challenge race series. Engines stock but matched for power output, were built at the Flint engine plant, sealed and shipped to Bowling Green for standard assembly. The cars weren't built in sequence because the Corvette plant built in colour batches. Fifty cars were sent to Protofab in Wixom, Michigan for installation of roll cages and other gear. During the season, most engines were exchanged by Chevrolet for new, sealed engines with more evenly calibrated power output.
New six-slot 1 6x8.5 wheels were standard with P255/50ZR16 tyres
RPO Z51 and RPO Z52 content changed slightly for 1988. Both had newly styled 17x9.5-inch wheels with twelve cooling slots, and P275/ 40ZR17 tyres. Z51 had higher spring rates and finned power steering cooler as before, but in 1988 it also received larger front brake rotors and calipers. RPO Z51 was limited to manual transmission coupes. RPO Z52 was not restricted.
All 1988 Corvettes had new dual-piston front brakes and parking brakes which activated the rear pads instead of activating small, separate parking drum brakes as in all previous disc-brake Corvettes.
Ratings for the 1988 RPO B2K Callaway Twin Turbo were 382hp and 562 Ib.-ft torque. Automatic transmissions (reworked truck Turbo Hydra-Matic 400s) were available for $6,500. Either Z51 or Z52 suspensions could be specified. Later production with Z52 had Z51's larger front brakes mufflers, longer air dams, and steering coolers because RPO B2K triggered these through Special Equipment Option (SEO) Z5G. Engines were reworked by Callaway at its Old Lyme, Connecticut shop.
All 1988s had an improved hood support rod and a more efficient, higher capacity air conditioning compressor manufactured by Nippondenso.
A 350ci,240/245hp engine,4-speed automatic transmission, removable body-colour roof panel (coupe) or soft top (convertible), and cloth seats were included in the base price.
RPO Z51 included B4P, FG3, KC4, V01, heavy-duty suspension, 17x9.5 wheels, and fast steering ratio. Limited to manual transmission coupes. RPO Z52 included B4P, FG3 and KC4,17x9.5 wheels, and fast steering.
RPO B2K generated a specific equipment build with standard engines at the Corvette assembly plant. The cars were then sent to Callaway's Connecticut shop for installation of Callaway-modified twin-turbo engines.
Restrictions applied to some soft top and interior colour combinations. Two-tone combinations of gray/charcoal and white/silver were indicated in early dealer order guides, but were dropped prior to 1988 production.
Road & Track test results for 1988: 0-60mph in 6.0 secs, 1/4 mile in 14.6 secs @ 95.5 mph.
PRODUCTION: 26,412: 16,663 coupes, 9,749 convertibles.
Vehicle: 1G1YY2186K5100001 thru 1G1YY2186K5126328
The RPO MN6 manual transmission no-cost option for 1989 was a new 6-speed designed jointly by ZF (Zahnradfabrik Friedrichshafen) and Chevrolet and built by ZF in Germany. A computer-aided gear selection (CAGS) feature bypassed second and third gears (and locked out fifth and sixth) for improved fuel economy in specific non-performance conditions.
The Corvette Challenge race series terminated at the end of the 1989 season. For 1989, Corvette's Bowling Green assembly plant built sixty Challenge cars with standard engines. Meanwhile, CPC Flint Engine built special, higher horsepower engines which were shipped to the Milford Proving Grounds for storage, then to Specialized Vehicles Inc. (SVI), Troy, Michigan, where they were equalized for power and sealed. Bowling Green sent thirty cars to Powell Development America, Wixom, Michigan, where the roll cages and safety equipment were installed and the engines from SVI were switched with the original engines. At season's end Chevrolet returned the original numbers-matching engines to each racer.
The RPO Z51 performance handing package option continued in 1989 available only in coupes with manual transmissions. A new suspension option, RPO FX3, permitted three variations of suspension control regulated by a console switch. It could be ordered only with RPO Z51 The RPOZ52 sport suspension (1987-1988) was not a 1989 option. However though all 1989 Corvettes with FX3 were Z51 s, these had Z52 springs and stabilizers for a wider range of suspension control. The only exceptions were the sixty Corvettes built for the Challenge race series which had FX3 suspensions with Z51 springs and stabilizers.
The standard six-slot, 1 6x8.5-inch wheel introduced in 1988 was discontinued for 1989. The twelve-slot, 1 7x9.5-inch style included with 1 988's Z51 and Z52 options became 1 989's standard equipment wheel.
On April 19,1989, Chevrolet advised dealers that the ZR-1 would be a 1990 model, not a late-release 1989. The reason cited was "insufficient availability of engines caused by additional development." Eighty-four (84) 1 989 ZR-1 Corvettes were built for evaluation, testing, media preview and photography, but none were released for public sale.
Seats were restyled, but the three choices of cloth, optional leather, or optional sport leather continued. Due to weight and fuel economy factors Chevrolet intentionally limited sales of the sport leather seats by making them available exclusively with Z51-optioned models during 1989.
The manual top mechanism was simplified for 1989 convertibles.
body-colour roof pane (coupe) or soft top (convertible), and cloth seats were included in the base price. RPO Z51 included B4P, KC4, V01, heavy-duty suspension, and fast steering ratio. Limited to manual transmission coupes..
New convertible options for late 1989 introduction included an RPO V56 rear luggage rack, and RPO CC2 removable hardtop.
RPO AQ9 leather sport seats and RPO FX3 selective ride and handling were available only when ordered with RPO Z51.
RPO B2K generated a specific equipment build with standard engines at the Corvette assembly plant. The cars were then sent to Callaway's Connecticut s hop for installation of Callaway-modif ied twin-turbo engines.
Code 90 Gray was cancelled in November, 1988.
Though not listed on 1989 exterior colour availability charts, Chevrolet records indicate six code 35 Yellow, and twenty-seven code 31 Arctic Pearl 1989 Corvettes were built.
1990
Production: 23,646: 16,016 coupe, 7,630 convertible
Vehicle: 1G1YY2380L5100001 thru 1G1YY2380L5120597
1G1YZ23J6L5800001 thru 1G1YZ23J6L5803049 (ZR1)
For Callaway twin-turbo, Chevrolet engine coding was replaced as follows: First two digits for year, next three digits for Callaway sequence, last four digits to match last four digits of vehicle identification number.
The ZR-1 (RPO ZR1) arrived as a 1990 model after much anticipation. At the heart of the ZR-1 was the 375hp LT5 engine. It was designed with the same V-8 configuration and 4.4-inch bore spacing as the standard L98 Corvette engine, but was an otherwise new design with four overhead camshafts and 32 valves. LT5 engines were manufactured and assembled by Mercury Marine in Stillwater, Oklahoma, then shipped to the Corvette Bowling Green assembly plant for ZR-1 vehicle assembly. For a limited time during 1990 dealers could order Corvettes destined for the new World Challenge race series. Merchandising code R9G triggered deviations from normal build such as heavy-duty springs with FX3. Owners could buy race engines from Chevrolet or build their own, and all race modifications were the owner's responsibility. Twenty-three 1990 R9G Corvettes were built.
An air intake speed density control system, camshaft revision, and compression ratio increase added 5hp to base-engines up from 240hp to 245hp (except coupes with 3.07:1 or 3.33:1 axle ratios which increased from 245hp to 250hp because of their less-restrictive exhaust systems).
1990 Corvettes had improved ABS and improved yaw control.
An engine oil life monitor calculated useful oil life based on engine temperatures and revolutions. An instrument panel display alerted the driver when an oil change was recommended.
The RPO V01 radiator and B4P boost fan were not optional in 1990, both made unnecessary by 1990's more efficient, sloped-back radiator design.
Two premium 200-watt Delco-Bose stereo systems were available, the top unit featuring a compact disc player. To discourage theft, the CD required electronic security code input after battery disconnect.
The instrument panel for 1990 was redesigned as a "hybrid," combining a digital speedometre with analog tachometre and secondary gauges. A supplemental inflatable restraint system (SIR) with airbag was added to the driver side, a glovebox to the passenger side.
The "ABS Active" light was removed from the driver information centre.
Seat designs were the same for 1990 as the previous year, except the backs would latch in the forward position.
A 350ci, 245/250hp engine, 4-speed automatic transmission, body-colour roof panel (coupe) or soft top (convertible), and cloth seats were included in the base price.
RPO ZR1 included unique bodywork (doors, rear quarters, rockers, rear facia, and rear upper panel) to accept Goodyear Z-rated P315/35ZR17 tyres on 11 -inch wide rear rims. RPOs AC1, AC3, AQ9, FX3, LT5 (32-valve engine, exclusive to the ZR-1), Up F. UJ6 and a specially laminated "solar" windshield were included. RPO MN6 manual transmission was required. Available in coupe body style only.
Chevrolet service departments returned LT5 engines to Mercury Marine for certain repairs. Customers had the choice of a replacement engine, or return of their original engine if repairable.
Production: 14,967 coupe, 5,672 convertible, 20,639 total
VIN: 1G1YY2386M5100001 thru 1G1YY2386M5118595
1G1YZ23J6M5800001 thru 1G1YZ23J6M5802044 (ZR- 1)
All 1991 Corvettes had restyled rear exteriors which are similar in appearance to the 1990 ZR-1 because both had convex rear facias with four rectangular tail lamps. Both standard models and ZR-1 s also featured new front designs with wraparound parking-cornering-fog lamps, new side panel louvers, and wider body-side mouldings in body colour. Despite similar appearance, the 1991 ZR-1 still received unique doors and rear body panels to accept 11 -inch wide rear wheels. The high-mount centre stop lamp for 1991 ZR-1 s continued to be roof-mounted. For all other than ZR-1, the lamp was integrated into the new rear facia.
Base wheels were same size as 1990 (17x9.5), but a new design.
Finned power steering coolers were included with all 1991 models.
A new option, RPO Z07, essentially combined the previously available Z51 performance handling package with FX3 selective ride/handling. But there were differences. In 1990, if FX3 and Z51 were combined, some base suspension components were used to provide an adjustable suspension range from soft to firm. The new RPO Z07 option used all heavy duty suspension parts so the ride adjusted from firm to very firm. Intended for aggressive driving or competition, Z07 was limited to coupes
The World Challenge race series continued in 1991, but Bowling Green did not build specific Corvettes for the series. All race modifications were the owners' responsibility.
Callaway Twin-Turbo conversions ended with the 1991 model year. Callaway built the 500th twin-turbo on 9-26-91 and subsequent builds were specially badged and optioned (extra $600) as "Callaway 500."
A power wire for cellular phones or other 12-volt devices was added.
A power delay feature was added to all models which permitted the stereo system and power windows to operate after the ignition was switched to 'off'' or "lock." Power was cut after the driver door was opened, or after fifteen minutes whichever occurred first.
A sensor utilizing an oil pan float was added to all models. The words "low oil" appeared on the driver information centre to signal a low oil condition.
Mufflers were revised for 1991 with larger section sizes and better control tuning of exhaust note. The mufflers had lower back pressure for improved performance, but power ratings were not changed.
The AM band for radios was expanded to receive more frequencies.
The ZR-1 "valet" power access system continued, but was revised to default to normal power on each ignition cycle. The full power light was relocated next to the valet key.
A 350ci,245/250hp engine,4-speed automatic transmission, removable body-colour roof panel (coupe) or soft top (convertible), and cloth seats were included in the base price.
RPO Z07 included KC4, FX3, heavy-duty springs, shocks, stabilizers and bushings, and heavy-duty brakes. Available manual transmission only.
RPO ZR 1 included unique bodywork (doors, rear quarters, rear facia, and rear upper panel) to accept Goodyear Z-rated P315/35ZR17 tyres on 11 inch wide rear rims. RPOs AC1, AC3, AQ9, C68, FX3, LT5 (32-valve engine exclusive to the ZR-1), Up F. UJ6, and a specially laminated "solar" windshield were included. RPO MN6 manual transmission was required. Available in coupe body style only.
1992
Production: 20,479: 14,604 coupe, 5,875 convertible
VIN: 1 G1 YY23P6N5100001 thru 1 G1 YY23P6N5119977
1G1YZ23J6N5800001 thru 1G1YZ23J6N5800502 (ZR-1)
Exterior appearance for 1992 was little changed. For the ZR-1, "ZR-1 '' emblems were added above the side fender vents. Two rectangular exhaust outlets were used for ZR-1 s and for standard models. Instrument face plates and buttons were changed to all-black, replacing 1990-1991's gray-black. The digital speedometre was relocated above the fuel gauge. Gauge graphics were refined for better legibility.
The base engine for 1992 was the LT1, a new generation small block. In 1992 Corvettes, the engine developed 300hp (net) at 5000 rpm. Torque was 330 Ib.-ft at 4000 rpm. Redline was 5700 rpm, 700 higher than the L98. There was an automatic fuel cutoff at 5850 rpm. Power Increases were attributed to computer-controlled ignition timing, a low-restriction exhaust system employing two catalytic converters and two oxygen sensors (one converter and one oxygen sensor for each cylinder bank), higher compression ratio, new camshaft profile, free-flow cylinder heads, and a new multiport fuel injection (MFI) system. At 452 pounds, the 1992 LT1 outweighed the 1991 L98 base engine by twenty-one pounds, due partly to replacement of stainless steel exhaust manifolds with cast Iron.
Corvette's new LT1 engine employed reverse flow cooling, a Chevrolet first. Rather than route coolant from the pump through the block to the heads, the LT1 routed coolant to the heads first. This permitted higher bore temperatures and reduced ring friction, and helped cooling around the valve seats and spark plug bosses.
Synthetic oil was recommended for the LT1. An engine oil cooler was no longer available, thought unnecessary when synthetic oil was used.
Traction control was standard for all 1992 Corvettes. Called Acceleration Slip Regulation (ASR), it was created by Bosch and developed with Corvette engineers. It engaged with the ignition, but could be turned off by an instrument panel switch. ASR used engine spark retard, throttle close down, and brake intervention to limit wheel spin when accelerating. When on and active, a slight accelerator pedal pushback could be felt. New Goodyear GS-C tyres were introduced as standard equipment on all 1992 Corvettes and were exclusive to Corvettes worldwide for 1992. The GS-C tread design was directional and asymmetrical.
Improvements in weather sealing were achieved with improved weatherstrip seals. Road noise reduction came from additional insulation in doors and improved insulation over the transmission tunnel.
The power delay feature was modified so that the passenger door also cut power, in addition to the driver door or fifteen minute time period.
The 1 -millionth Corvette, a 1992 white convertible, was built July 2,1992.
The Corvette Americana Hall of Fame and Americana Museum, created by Dr. Allen Schery, opened July 31, 1992, in Cooperstown, New York.
RPO Z07 included RPO FX3, heavy-duty suspension and heavy-duty ra es. Available with manual or automatic transmission
RPOZR1 Included unique bodywork(doors rear quarters rear facia and rear upper panel) to accept Goodyear Z-rated P315/35ZR17 tyres on 11 inch wide rear rims.
1993
Production: 21,590: 15,898 coupe, 5,692 convertible
VIN: 1G1YY23PXP5100001 thru 1G1YY23PXP5121142
1G1YZ23J3P5800001 thru 1G1YZ23J3P5800448 (ZR1)
Exterior appearance continued virually unchanged for 1993 , but a 40th Anniversary Package (RPO Z25) was optional with all models. The package included a Ruby Red metallic exterior, Ruby Red leather sport seats, power driver seat, special wheel centre trim and emblems.
Horsepower for the base LT1 engine remained 300, but three changes made the engine quieter. First, the heat shield design changed from a single-piece stamping to a two-piece sandwich type that was self-damping. Second, new thermoset polyester valve covers with "isolated" mounts replaced 1992's magnesium covers. Third' the LT1 camshaft exhaust lobe profile was modified to reduce the exhaust valve closing velocity. Also, a shortening of the inlet duration permitted more duration for the exhaust so there was no increase in overlap area. Emissions and idle quality weren't adversely affected. A side benefit of closing the inlet valve sooner was an increase in torque from 330 to 340 lb.-ft at 3600 rpm.
Horsepower increased for the optional ZR1's LT5 engine from 375 to 405hp, a result of modifications to the cylinder heads and valve train. Other changes included four-bolt main bearings, a Mobil 1 synthetic oil requirement, platinum-tipped spark plugs, and an electrical, linear exhaust gas recirculation (EGR) system for improved emission control.
The 1993 Corvette was the first auto sold by GM to feature a passive keyless entry (PKE) system. Working by proximity, a battery-operated key-fob transmitter sent a unique code picked up by a receiver in the Corvette through one of the two antennas ( in coupes, antennas were in the driver door and rear deck; in convertibles, antennas were in both doors). The transmitter required no specific action by the owner; approaching the vehicle with the transmitter would unlock the doors, turn on the interior light, and disarm the theft-deterrent. Leaving an unlocked vehicle with the transmitter would lock the doors and arm the theft-deterrent. The PKE could be turned off completely and transmitters were programmable for locking and unlocking just the driver door, or both driver and passenger doors. Transmitters for convertibles had a single button for programming and driver/passenger door unlocking; transmitters for coupes had an extra button for rear hatch release.
Front wheels for base cars were decreased from 9.5x17 to 8.5x17 and the front tyre size from P275/40ZR17 to P255/425ZR17. Rear tyre size was increased from P275140ZR17 to P285140ZR17. For RPO Z07, 9.5x17 wheels and P275140ZR17 tyres were used front and rear.
Although the same in design as the previous model, 1993's wheels had a different surface appearance due to a change in fmish machining.
1994
Production: 23,330: 17,984 coupes, 5,346 conv.VIN: 1G1YY22P9R5100001 thru 1G1YY22P9R5122882
1 G1 YZ22J9R5800001 thru 1G1YZ22J9R5800448 (ZR1 )
Interior revisions included addition of a passenger-side airbag and knee bolster (and removal of the instrument panel glovebox), new seat and door trim panel designs, finer-weave carpetmg, "express down" driver's power window, and a redesigned two-spoke airbag steering wheel. New white instrument graphics turned to tangerme at night. The tyre jack was relocated from the exterior spare tyre well to an inside compartment behind the passenger seat. For 1994, all seats were leather. Base and optional "sport" styles were available. Both featured less restrictive bolsters to accommodate a wider range of occupant sizes and for improved entry and exit. Controls for base seats with optional power assist were console-mounted with individual controls for driver and passenger. With sport seats, a single set of power assist controls for both seats was console-mounted. Also, individual motors adjusted the lumbar support for sport seats and these controls (and the side bolster control) were relocated from the seat to the console for 1994. Reclining mechanisms for all 1994 seats were manual.
Spring rates for RPO FX3 (selective ride control) were lowered to improve ride quality. For the same reason, recommended tyre pressures were reduced from 35psi to 3Opsi (except Zrl).
After years of planning under the direction of National Corvette Museum Foundation president Dan Gale, the National Corvette Museum opened to the public on September 2 1994, in Bowling Green, Kentucky.
The exterior design for 1994 was carried over from 1993, but two new exterior colours were available, Admiral Blue and Copper Metalilc. Also, new non-directional wheels were included with ZR-1 models.
Power output of the base LT1 engine remained 300hp, but several refinements were added. A new sequential fuel !njection system Improved response idle quality, driveability and emissions by flnng Iniectors In sequence with the engine's firing order. A more powerful sgnibon system reduced engine start times, especially in cold temperatures.
The standard 4-speed automatic transmission was redesigned with electronic controls for improved shift quality and rpm shift-point consistency Also, asafety interlockwas added which required depression of the brake pedal in order to shift from "park."
A passenger-side airbag and knee bolster, new seat and door trim panel designs "express down" driver's power window, and a redesigned twospoke airbag steering wheel were new inside. New white instrument graphics turned to tangerine at night. The tyre jack was relocated from the exterior spare tyre well to a compartment behind the passenger seat.
For 1994, all seats were leather. Base and optional "sport" styles were available. Both featured less restrictive bolsters to accommodate a wider range of occupant sizes and for improved entry and exit. Controls for base seats with optional power assist were console-mounted with Individual controls for driver and passenger. With sport seats, a single set of power assist controls for both seats was console-mounted. Also, Individual motors adjustedthe lumbarsupportforsport seats andthese controls (and the side bolster control) were relocated from the seat to the console for 1994. Reclining mechanisms for all 1994 seats were manual.
The rear window for convertibles was changed from plastic to glass and included an in-glass defogger.
RPO FX3 spring rates were lowered to improve ride quality; recommended tyre pressures were reduced from 35psi to 30psl (except ZR1).
Air conditioning systems were revised to use R-1 34A refrigerant, a nonozone depleting CFC substitute.
Optional Goodyear Extended Mobility Tyres (RPO WY5) had special bead construction to permit usewith no air pressure. The lowbre pressure warning system (RPO UJ6) was required because if the tyre was run deflated more than about fifty miles, damage could result. However, the safe driving range was substantially further.
A 350ci, 300hp engine, 4-speed automatic transmission, removable body-colour roof panel (coupe) or soft top (convertible) Delco stereo system with cassette, and leather seats were included in the base price.
Preferred Equipment Group One included electronic air conditioning control, Deico Bose stereo system with cassette and power driver seat
RPO G92 was available without restriction
RPO WY5 required RPO UJ6; not available with RPOs Z07 or ZR1
RPO Z07 included RPO FX3, heavy-duty suspension and heavy-duty brakes. Avallable with manual or automatic transmission
RPOZR1 included unique bodywork (doors, rearquarters rearfacia and rear upper panel) to accept Goodyear Z-rated P315/35ZR17 tyres on 11 Inch wide rear wheels (front and rear wheel design for 1994 was new and unique to the ZR-1). Electronic air conditioning control and RPOs AC1, 68, FX3, LT5 (32-valve engine exclusive to the ZR-18, U1 F UJ6, and a specially laminated "solar" windshield were included.
1995
Production: 20,742: 15,771 coupe, 4,971 convertible
VIN: 1G1YY22P7S5100001 thru 1G1YY22P7S5120294
1G1YZ22JOS5800001 thru 1G1YZ22JOS5800448 (ZR1)
The 1995 exterior was distinguished from 1994 by restyling of the front fender "gill" air vents. A new exterior colour, Dark Purple Metallic, was added, but 1994's Copper Metallic and Black Rose Metallic were deleted. Corvette paced the Indianapolis 500 race in 1995. A replica, Dark Purple and White (convertible only) with special accents, sold 527 units.
Optional Sport Seats had stronger "French" seam stitching. A readout for automatic transmission fluid temperature was added to the instrument display. Out of sight were numerous Velcro straps to reduce rattles, and a stronger radio mount for less CD skipping. A drip tube was designed into the A-pillar weatherstrip for improved water intrusion control.
The base LT1 engine continued with the same 300hp and 340 Ib-fttorque ratings, but there were refinements. Late in 1994 production, connecting rods were changed to a powdered-metal design to improve both strength and weight uniformity. Fuel injectors were revised to better cope with alcohol-blend fuels and to reduce fuel dripping after engine shutdown. The engine cooling fan was modified for quieter operation.
This was the ZR-1 's last year. Mercury Marine in Stillwater, Oklahoma, completed all LT5 engines in November 1993. Tooling, owned by GM, was removed from Mercury Marine's factory and all engines, specially sealed, were shipped to Corvette's Bowling Green assembly plant for storage until needed. Before September 1, 1993, all internal engine warranty repair was done by Mercury Marine. Between September 1,1993 and December 31,1993, internal repairs were done by Mercury Marine if engines had under 12,000 miles or 12 months service. Chevrolet handled service not performed by Mercury Marine, including all after January 1, 1994. Total 1995 ZR-1 production was predetermined at 448 units, the same as 1993 and 1994. Total ZR-1 production for 1990 through 1995 was 6,939.
Clutch controls in the four-speed automatic transmission were improved for smoother shifting, and its torque converter was both lighter and stronger. The 6-speed manual was redesigned by replacement of the reverse lockout with a high-detent design for easier operation.
The larger brake package, included previously with Z07 and ZR-1 performance options, was included for 1995 with all models. And all 1995's had the latest anti-lock traction control (ABS/ASR-5) system.
The extended mobility "run flat" tyres introduced as a 1994 option minimized the need for a spare tyre. So t 995's RPO N84 created a delete spare option which reduced weight and included a credit of $100.00.
Base suspension models had lower front and rear spring rates.
Windshield wiper arms were redesigned with revised contact angles and hiqher contact force to reduce chatter at all speeds, and lift at high speeds.
A 350ci, 300hp engine, 4-speed automatic transmission, removable body-colour roof panel (coupe) or soft top (convertible) Delco stereo system with cassette, and leather seats were included in the base price.
Production: 21,536 : 17,167 coupe, 4,369 convertible
VIN: 1G1YY2257T5100001 thru 1G1YY2251T5120536
1G1YY2251T5600001 thru 1G1YY2251T5601000 (Grand Sport)
A new version of Chevy's 350-cubic-inch small block, RPO LT4, became optional exclusively with 1996 Corvettes. Rated at 330-horsepower, 30 more than the base LTl, the LT4 had higher compression (10.8:1 vs 10.4:1), new aluminum head design, Crane roller rocker arms, revised camshaft profile, and other major and minor tweaks. The LT4's redine increased to 6300 rpm (5700 rpm for LT1), so LT4-equipped models had 8000 rpm tachometres instead of the base 6000 rpm. LT4 was available with all Corvette models, but only with manual transmissions.
LT1 engines were mated only to automatic transmisslons which had improved friction materials for the intermediate clutch and fronfrear bands, improved shift quality and more durable torque converters.
"Grand Sport" (RPO Z16) included the LT4 engine, distinctive Admiral Blue paint with white centre stripe, and special detalilng. The previous year's ZR-1-style five-spoke 17" wheels were used, but painted black. Like the ZR-1, tyres for Grand Sport coupes were P275/40ZR17 front and P3t 5/35ZR17 rear. But Grand Sport coupes had rear fender flares rather than the ZR-1's wider rear panels. Convertible Grand Sport tyres were P255/45ZR17 front, P285/40ZR17 rear, with no fender flares. ntenor choices were limited to black, or a red-black combination. Corvettes with the Grand Sport option had separate senal number sequences.
LT1 and LT4 engines had a new throttle body for 1996. Those for LT4 engines had red "Grand Sport" lettering, regardless of the application.
"Collector Edition" (RPO Z15) included Sebring Sliver paint and special trim ZR-1-style 17" five-spoke wheels were used, but painted silver with P255/45ZR17 front and P285/40ZR17 rear tyres. Black, red or gray interiors were available, but soft top colour choice was limited to black.
RPO F45 Selective Real Time Damping, was pnced the same ($1,695) as 1 995's FX3 Selective Ride option, but was substantially different. Using data from wheel travel sensors and the Powertrain Control Module, a controller calculated the damping mode that would provide opumum control via special shock absorbers. It could alter each shock individually (unlike the earlier system which changed all shocks simultaneously) every 10 to 15 milliseconds or about every foot of roadway travelilng at 60 mph.
Performance Handling Package (RPO Z51) previously optional from 1984 thru 1990, returned in 1996 with different content but similar Intent. It included Bilstein shock absorbers with stiffer springs and thicker stabllizer bars. If ordered with an automatic transmission, a 3.07:1 axle was required. TyreswereP275/40ZR17On17x9.5"aluminumwheels,except for Z51 Grand Sports which had P315/35ZR17 rear tyres on 17x11" wheels Z51 was limited to coupes.
1996's On-Board-Diagnostics were much more sophisticated and complex, the number of diagnostic codes increasing from 60 to 140.
A 350ci, 300hp engine, 4-speed automatic transmission, removable ody-colour roof panel (coupe) or soft top (convertible), Delco stereo system with cassette, and leather seats were included in base prices. Preferred Equipment Group (PEG) 1 included electronic air conditioning control, Delco-Bose stereo with cassette, and RPO AG1 for $1,333.00.
15 Included 17" 5-spoke wheels painted silver, black brake calipers with silver "Corvette" lettering, Sebring Silver exterior paint special emblems, P255/45ZR17 front tyres, P285/40ZR17 rear tyres, and perforated sports seats with "Collector Edition" embroidery
RPO Z16 included Admiral Blue paint with white stripe, red left-fender ash marks, 17" 5-spoke aluminum wheels painted black, black brake calipers with silver "Corvette" lettering, P275/40ZR/17 front and P315/35
/17rear tyres (coupe), rearwheelflares (coupe), blackfloormats, and perforated sport seats with "Grand Sport" embroidery RPO Z51 had Bilstein shocks, special front and rear springs, stabilizers and bushings, 1 7x9.5"wheels with P275/40 ZR 17 tyres. (Z16 with Z5 1 had 17x11"rearwheelswithP315/35ZR17tyres). Z51 requiredAG1 andAG2. vai able with manual or automatic, but automatic required G92.
THE (C4) END Vettes Down Under
