Every once in a while, the photography for a Vette car feature falls through the cracks and disappears into the abyss, but we believe Robert Lombardi’s 1992 Chevrolet C4 Corvette photographed by John Machaquiero in 2015 sets a new record. A lot can happen in five years, so we were quite pleased when Robert returned our call and gave Vette the lowdown on the ’92 Corvette coupe he used to own.
Prior to the ’92 C4, Robert owned a 1987 Porsche 928 GT4, but said it wasn’t fast enough and it would have cost too much to modify. Robert made a visit to Corvette Conspiracy in Cleveland and bought one of the 1,995 1992 Corvettes finished in Pollo Green II metallic. Consequently, Corvette Conspiracy was Robert’s go-to for all of the modifications made to make the C4 a real sleeper.
Fitting under a stock ’92 hood, the 350-inch LT1 was punched out to 396 inches with a Callies Magnum stroker assembly hung with eight Mahle 9.0:1 pistons topped with AFR 195cc LT4 Eliminator street heads. The valvetrain centers around a Comp Cams camshaft with 0.544 intake and 0.544 exhaust lift. The intake manifold is a modified LT4 matched to a modified LT4 fuel-injection system. An intercooler and K&N air filter round out the major induction bits. The big 585 dyno-proven rear-wheel horsepower comes from an ATI ProCharger supercharger. The infamously bad Opti-Spark was swapped for ACCEL DFI Gen 7.0 coil-over-plug ignition with a FAST controller. The exhaust features Melrose headers into a complete Billy Boat 3-inch stainless steel exhaust system.
Producing 585 hp and 565 lb-ft of torque to the rear wheels and matching the automatic transmission and differential to cope didn’t happen all at once. On the Dynojet dyno it was noticed no matter how tight the belt was tightened it slipped, and the power dropped. The cure was to machine Gilmer drive pulleys for the supercharger and equip it with a cogged Kevlar belt. With the belt slippage fixed, the stock 700-R4 transmission shattered and scattered its innards and was replaced with a Hayden-cooled Gearstar Level 4 700-R4 rated to handle the big horsepower. Set up and installed by Corvette Conspiracy, the rearend is a Dana 44 with 3.45 gearing. For increased cooling ability, a large-capacity radiator was installed.
The brakes and suspension on Robert’s ’92 started out as garden-variety, standard C4 issue. To upgrade, front and rear Bilstein sport shocks and polyurethane bushings were installed, plus a 1986 Corvette convertible X-brace was bolted to existing pickup points. The front brakes were updated to 1996 Grand Sport specs with drilled rotors. For wheels and tires, in front 295/35R18 Nitto Invo tires are mounted on black 18×9 Scorpion wheels and 325/30R19 Nitto Invo tires on 19×10.5 black Scorpion wheels in the rear.
Robert’s ’92 C4 came factory equipped with light beige leather AQ9 sport seats and Delco-Bose sound system. Corvette Conspiracy swapped the Delco-Bose out for a Pioneer AVH-5600BHS head unit with an Alpine DDX 4-150 amp and front speakers. Bringing up the rear are Alpine SPR136A SPR 175A speakers, and for bass response, two Bazooka BTA6250D bass tubes. The driver-side A-pillar houses two carbon-fiber Auto-Meter gauges: one for fuel pressure and the other boost/vacuum.
In the seven years it took to outfit Robert’s ’92 Chevrolet C4 Corvette coupe as it appears here the car served as a daily driver, street racer and show car with vacation trips to the Florida Keys and a few visits to the National Corvette Museum in Bowling Green, Kentucky. Robert told us he’s gaining interest repeating his Corvette Conspiracy experience, but this time with a C6.
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