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C4 Corvette Facts

Model Years: 1984 to 1996

lil' red corvette

1984 C4 Corvettes

 

  1. The 1984 Corvette was a complete redesign in almost every aspect. Handling considerations dominated and the result was praised by the motoring press ans the world’s best cornering automobile.
  2. 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.
  3. 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 center tunnel.
  4. A 4+3 4-speed manual transmission, built by Doug Nash, had overdrives in the top three gears for improved fliel economy. Not available early.
  5. 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%.
  6. Brakes remained disc at all four wheels, but components were new and included aluminum calipers supplied by Girlock of Australia.
  7. 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.
  8. 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 Adrainistration dropped the restraint proposals, but the Corvette’s pad remained.
  9. 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 entire body.
  10. 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.
  11. 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 fliel capability, and electrical, glass, lighting and mirror modifications.
  12. Single transverse plastic leaf springs were used front and rear.

 

1985 C4 Corvettes

 

    1. The 1982 and 1984 Corvette engines had “Cross Fire Injection”, but genuine fliel injection returned to the Corvette in 1985 for the fffst 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 2OShp to 230hp, a torque increase from 290 lb.-ft to 330, and a real-world fliel economy increase of about 11%.
    2. The overdrive selection switch for 4-speed manual transmissions was moved during 1985 production from the console to the gear shift knob.
    3. 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 fro RPO Z51 were 16% softer in front and 25% softer in the rear. To compensate for the spring change, larger-diameter stabilizer bars were included with Z51 equipped models.
    4. In its January 1985 “ten best” issue, Car and Driver

magazine pronounced the Corvette to be America’s fastest production car at an even 150mph top speed. Corvette also took top honors in top-gear acceleration and tied for best (with Porsch) in roadholding as measured by 0-force skidpad adhesion.

  1. 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.
  2. Manual transmission 1985s came with a new, heavy-duty 8.5-inch ring differential. Rear axle gearing for manuals was 3.07:1, Standard gearing for automatic transmission was 2.73:1, but the 3.07:1 could be ordered as RPO 092. Wheel balance weights changed in 1985 from the outside-rim, clip-on style, to an inner-surface adhesive type. The changer was mainly for aesthetics, but Chevrolet also believed a better balance resulted because of the adhesive weight’s proximity to the wheel’s depth center.
  3. A flill length oil pan gasket reinforcement was added tot he 1985 Corvette engine to improve gasket compression seal.
  4. Electronic instrumentation continued much as the previous year, but displays were revised and improved with cleaner graphics, less color on the speedometer and tachometer, and larger digits for the center-cluster liquid crystal displays.
  5. A map strap was added to the 1985’s drive-side sun visor.

 

 

1986 C4 Corvettes

 

  1. Electronic air conditioning was announced as a late 1985 option, but introduction was delayed into the 1986 model year.
  2. 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
  3. An anti-lock brake system (ABS) became standard with 1986 Corvettes. An adaption of Bosch’s system, Corvettes’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.
  4. Cracking around the head attachment bosses required an introduction delay for design revisions to 1986’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 Shp.
  5. Center 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.
  6. A new vehicle anti-theft system ATS) 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.
  7. Caster was changed in 1986 from four degrees to six degrees to improve on-center road feel and to decrease wander.
  8. Fifty “Malcolm Konner Commemorative Edition” 1986 Corvettes were built in a special arrangement honoring the New Jersey Chevrolet dealership’s founder, Malcolm Konner.
  9. Each Corvette had special two-tone paint schemes, Silver Beige over Black, coded “spec”.Window stickers reflected 4OO1ZA as the RPO, and a $500 cost for MALCOLM KOONER SP.EDIT.PAI. All were coups, twenty with manual transmissions, thity with automatics.
  10. All had graphite leather interiors. One was retrofitted with a Callaway twin-turbo engine.
  11. The angle of the 1986 digital instrument display was changed to improve daytime viewing by reducing glare.
  12. A new upshift indicator light for manual and automatic transmission 1986 models was intended to improve fliel economy.
  13. “Low coolant” and “anti-lock” instrument displays were added.
  14. Wheel design was revised slightly for 1986, with the wheel center section natural finish instead of black as in 1984 and 1985.

 

1987 C4 Corvettes

 

  1. Friction reduction from roller valve lifters (new for 1987) resulted in a power increase to 240hp, up Shp from 1986’s aluminum-head engines.
  2. Center sections and radial slots of 1987 wheels were painted argent gray. 1986 wheel centers were not painted. Centers and radial slots for 1984 and 1985 were painted black.
  3. Convertibles and early coupes had outside mirror air deflectors.
  4. Chevrolet planned an RPO UJ6 low tire pressure indicator option, but the $325 option was on constraint during 1987 due to false signaling problems. However, Chevrolet records show forty-six units sold.
  5. The RPO Z52 package was refined to include structural enhancements developed for the convertible, and a fmned power steering fluid cooler.
  6. A new RPO Z52 “sport” handling package combined elements of ZS 1 with the softer suspension of base models. RPO Z52 included the radiator boost fan, Blistein shock absorbers, engine oil cooler, heavy-duty radiator, l6x9.5-inch 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.
  7. The overdrive-engage light was moved from the center-dash area (1984-86) to an easier-to-view location within the 1987 tach display.
  8. 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 lbs.-ft torque, and reached a top speed of 177.9 mph with .60 overdrive gearing. The first four 1987 Callaways used replacement LFS (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.
  9. Electronic air conditioning control (RPO C68) became an available option for coupes and convertibles in 1987; in 1986, it was coupe-only.
  10. New 1987 convenience options included and illuminated vanity mirror (D74) for the driver’s visor, and a passenger-side power seat base (AC 1). 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.

 

1988 C4 Corvettes

 

  1. Refinements for 1988 included carpeted door sills, solution-dyed carpet, improved “flow through” ventilation for coupes, and a lower, rearward relocation of the parking brake handle.
  2. Engine power remained at 240hp for 1988 models except for coupes with 3.07:1 axle ratios which had 245hp. The Shp increase came from less restrictive muffler which were deemed too loud for convertibles and 2.59:1 axle coupes.
  3. A thirty-frtth anniversary edition 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 totals 2,050 units.
  4. Chevrolet built fifty-six street legal Corvettes for the 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 color 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.
  5. New six-slot 16×8.5 wheels were standard with P255/50ZR16 tires.
  6. RPO Z51 and RPO Z52 content changed slightly for 1988. Both had newly styled 17×9.5-inch wheels with twelve cooling slots, and 1’275/4OZRl 7 tires. 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.
  7. 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.
  8. Ratings for the 1988 RPO B2K Callaway Twin Turbo were 382hp and 562 lb.-ft torque.
  9. 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 Z5l’s larger front brakes, mufflers, longer air dams, and steering coolers because RPO B2K triggered these through Special Equipment Option (SEO) Z50. Engines were reworked by Callaway at its Old Lyme, Connecticut shop.
  10. All 1988’s had an improved hood support rod and a more efficient, higher capacity air conditioning compressor manufactured by Nippondenso.

 

1989 C4 Corvettes

 

  1. The RPO MN 6 manual transmission no-cost option for 1989 was a new 6-speed designed jointly by ZF (Zahnradfabrik Friedrichshafen) and Chevrolet 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 fliel economy in specific non-performance conditions.
  2. The Corvette Challenge race series terminated at the end of the 1989 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 output 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 we switched with the original engines. At the end of the season, Chevrolet returned the original numbers-matching engines to each racer.
  3. The RPO Z5 1 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 RPO Z52 sport suspension (1987-1988) was not a 1989 option. However, through all 1989 Corvette with FX 3 were Z5 is, 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 Z5 1 springs and stabilizers.
  4. The standard six-slot, 16×8.5-inch wheel introduced in 1988 was discontinued for 1989. The twelve-slot, 1 7×9.S-inch style included with 1 988~s Z5 1 and Z52 options became 1 989~s standard equipment wheel.
  5. 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.” About 100 1989 ZR-1 Corvettes were built for evaluation, testing, media preview and photography, but none were release for public sale.
  6. Seats were restyled, but the three choices of cloth, optional leather, or optional sport leather continued. Due to weight and fliel economy factors, Chevrolet intentionally limited sales of the sport leather seats by making them only available exclusively with Z5 1 -optioned models during 1989. The manual top mechanism was simplified for 1989 convertibles


1990
C4 Corvettes

  1. 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-S configuration and 4.4-inch bore spacing as the standard L98 Corvette engine, but was an otherwise new design with four overhead camshaf~ and 32 valves. LT5 engines were manufactured and assembled by Mercury Marine in Stiliwater, Oklahoma, then shipped to the Corvette Bowling Green assembly plant for ZR-1 vehicle assembly.
  2. 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 FX 3. 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.
  3. An air intake speed density control system, camshaft revision, and compression ratio increase added 5hp to base-engines, up from 240hp to245hp (except coupes with 3.07:1 or 3.33:1 axle ratios which increased from 245hp to 250hp because of their less4estrictive exhaust systems).
  4. 1990 Corvettes had improved ABS and improved yaw control.
  5. An engine oil life monitor calculated useflil oil life based on engine temperatures and revolutions. An instrument panel display alerted the driver when an oil change was recommended.
  6. ·The RPO VOl radiator and B4P boost fan were not optional in 1990, both made unnecessary by 1990’s more efficient, sloped-back radiator design.
  7. 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.
  8. The instrument panel for 1990 was redesigned as a “hybrid,” combinlng a digital speedometer with analog tachometer and secondary gauges. A supplemental inflatable restraint system (SIR) with airbag was added to the driver side, a glovebox to the passenger side.
  9. The “ABS Active” light was removed from the driver information center.
  10. Seat designs were the same for 1990 as the previous year, except the backs would latch in the forward position.
  11. 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.

 

1991 C4 Corvettes

 

  1. All 1991 Corvettes had restyled rear exteriors which are similar in appe&ance to the 1990 ZR-1 because both had convex rear facias with four rectangular tall lamps. Both standard models and ZR-1 is also featured new front designs with wraparound parking-cornering-fog lamps, new side panel louvers, and wider body-side moldings in body color.
  2. Despite similar appearance, the 1991 ZR-1 still received unique doors and rear body panels to accept il-inch wide rear wheels. The high-mount center stop lamp for 1991 ZR-1 is continued to be roof-mounted. For all other than ZR-1, the lamp was integrated into the new rear facia.
  3. Base wheels were same size as 1990 (17 9.5), but a new design.
  4. Finned power steering coolers were included with all 1991 models.
  5. 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.
  6. 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.
  7. 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 “Cailaway 500.”
  8. A power wire for cellular phones or other 12-volt devices was added.
  9. 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.
  10. A sensor utilizing an oil pan float was added to all models. The words “low oil” appeared on the driver information center to signal a low oil condition.
  11. 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.
  12. The AM band for radios was expanded to receive more frequencies.
  13. 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.


1992
C4 Corvettes

  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-is and for standard models.
  2. Instrument face plates and buttons were changed to all-black, replacing 1990-1991’s grayblack. The digital speedometer was relocated above the fliel gauge. Gauge graphics were refined for better legibility.
  3. The base engine for 1992 was the LT1, a new generation small block. In 1992 Corvettes, the engine developed 3OOhp (net) at 5000 rpm. Torque was 330 lb.-ft at 40000 rpm. Redline was 5700 rpm, 700 higher than the L98. There was an automatic fliel cutoff at 5800 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 fliel 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 to exhaust manifolds with cast iron.
  4. 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.
  5. Synthetic oil was recommended for the LT1. An engine oil cooler was no longer available, thought unnecessary when synthetic oil was used.
  6. Traction control was introduced as standard equipment on all 1992 Corvette models. Called Acceleration Slip Regulation (ASR), Corvette’s system was created by Bosch and developed in cooperation with Corvette engineers. It was engaged automatically with the ignition, but could be turned off by an instrument panel switch. Corvette’s ASR used engine spark retard, throttle close down, and brake intervention to limit wheel spin when accelerating. When the system was on and active, the driver could feel a slight accelerator pedal pushback.
  7. New Goodyear GS-C tires 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.
  8. 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.
  9. 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.
  10. The 1-millionth Corvette, a 1992 white convertible, was built July 2, 1992

 

1993 C4 Corvettes

 

  1. 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 center trim and emblems.
  2. All leather seats in 1993 Corvettes had “4Oth” anniversary embroidery in the headrest area. The base black cloth seats did not.
  3. 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.
  4. 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.
  5. 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.
  6. Front wheels for base cars were decreased from 9.5×17 to 8.5×17 and the front tire size from P275/40ZR17 to P255/425ZR17. Rear tire size was increased from P275140ZR17 to P285140ZR17. For RPO Z07, 9.5×17 wheels and P275140ZR17 tires were used front and rear.
  7. 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 C4 Corvettes

 

  1. The exterior design for 1994 was carried over from 1993, but two new exterior colors were available, Admiral Blue and Copper Metallic. Also, new non-directional wheels were included with ZRl models.
  2. Power output of the base LT1 engine remained 3OOhp, but several refinements were added. A new sequential luel injection system improved response, idle quality, drive ability and emissions by f~ng injectors in sequence with the engine’s firing order. A more powertul ignition system reduced engine start times, especially in cold temperatures.
  3. The standard 4-speed automatic transmission was redesigned with electronic controls for improved shift quality and rpm shift-point consistency. Also, a safety interlock was added which required depression of the brake pedal in order to shift from “park.”
  4. 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 tire jack was relocated from the exterior spare tire well to an inside compartment behind the passenger seat.
  5. 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.
  6. The rear window for convertibles was changed from plastic to glass and included an in-glass defogger.
  7. Spring rates for RPO FX3 (selective ride control) were lowered to improve ride quality. For the same reason, recommended tire pressures were reduced from 35psi to 3Opsi (except ZRl).
  8. Air conditioning systems were revised to use R-134A refrigerant, a non-ozone depleting CFC substitute.
  9. Optional Goodyear Extended Mobility Tires (RPO WY5) had special bead construction to permit use with no air pressure. The low tire pressure wanning system (RPO UJ6) was required because if the tire was run deflated more than about fifty miles, damage could result. However, the safe driving range was substantially farther.

 

1995 C4 Corvettes

 

  1. The 1995 exterior was distinguished from 1994 by restyling of the front fender “gill” air vents. A new exterior color, Dark Purple Metallic, was added, but 1994’s Copper Metallic and Black Rose Metallic were deleted.
  2. Corvette paced the Indianapolis 500 race in 1995. A replica, Dark Purple and White (convertible only) with special accents, sold 527 units.
  3. Optional Sport Seats had stronger “french” seam stitching. A readout for automatic 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.
  4. The base LTl engine continued with the same 3OOhp and 340 lb-ft torque ratings, but there were refmement 5. 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 fliels and to reduce fliel dripping after engine shutdown. The engine cooling fan was modified for quieter operation.
  5. This was the ZR-1’s last year. Mercury Marine in Stiliwater, Oklahoma, completed all LTS engines in November 1993. Tooling, owned by GM, was removed from 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 December31, 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-i production for 1990 through 1995 was 6,939.
  6. 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.
  7. 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.
  8. The extended mobility “run flat” tires introduced as a 1994 option minimized the need for a spare tire. So 1995’s RPO N84 created a~delete spare option which reduced weight and included a credit of $100.00.
  9. Base suspension models had lower front and rear spring rates.
  10. Windshield wiper arms were redesigned with revised contact angles and higher contact force to reduce chatter at all speeds, and lift at high speeds.

 

1996 C4 Corvettes

 

  1. 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 tachometers instead of the base 6000 rpm. LT4 was available with all Corvette models, but only with manual transmissions.
  2. LTl engines were mated only to automatic transmissions which had improved friction materials for the intermediate clutch and front/rear bands, improved shift quality and more durable torque converters.
  3. “Grand Sport” (RPO Z16) included the LT4 engine, distinctive Admiral Blue paint with white center stripe, and special detailing. The previous year’s ZR-l style five-spoke 17″ wheels were used, but painted black. Like the ZR-l, tires for Grand Sport coupes were P275/4OZRl 7 front and P31 5?3SZRl 7 rear. But Grand Sport coupes had rear fender flares rather than the ZR-l’s wider rear panels. Convertible Grand Sport tires were P255145ZR17 front, P285140ZR17 rear, with no fender flares. Interior choices were limited to black, or a red-black combination. Corvettes with the Grand Sport option had separate serial number sequences.
  4. LT1 and LT4 engines had a new throttle body for 1996. Those for LT4 engines had red “Grand Sport” lettering, regardless of the application.
  5. “Collector Edition: (RPO Z 15) included Sebring Silver paint and special trim. ZR-1 style 17” five-spoke wheels were used, but painted silver with P255/45ZR1 7 front and P285/4OZRl 7 rear tires. Black, red, or gray interiors were available, but soft top color choices was limited to black.
  6. RPO F45, Selective Real Time Damping, was priced the same ($1,695) as 1995’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 optimum 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 traveling at 60 mph.
  7. Performance Handling Package (RPO Z51) previously optional from 1984 thru 1988, returned in 1996 with different content but similar intent. It included Bustein shock absorbers with stiffer springs and thicker stabilizer bars. If ordered with an automatic transmission, a 3.07:1 axle was required. Tires were P275/40ZR17 on 17×9.5″ aluminum wheels, except for Z51 Grand Sports which had P31 5/3SZR1 7 rear tires on I 7×11″ wheels. Z51 was limited to Coupes.
  8. 1996’s On-Board-Diagnostics were much more sophisticated and complex, the number of diagnostic codes increasing from 60 to 140.

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