1991 Chevrolet Corvette ZR1 - Out Of Reach

Nobody Can Touch This 10-Second, Nitrous-Fed, ZR1 Monster

Kevin Shaw Apr 10, 2007 0 Comment(s)
Corp_0703_04_z 1991_corvette_ZR1 Trunk 1/13

Magic
Rod's magic in a bottle is hidden here between the rear braces of the DRM cage. Computers help to distribute the special sauce over the power band, making the most out of the direct-injection system.

It wasn't long after Rod drove the Corvette home that he began digging inside the quad-cammer's internals. The Lotus-designed heads were ported and milled by fellow craftsman Greg Van Deventer. Once returned, Rod personally tackled the task of cutting a competition valve job on the heads. The factory valves were retained but with back-cut stems. The block was bored out and built to total 368 ci, but that manifestation didn't last long. A Jerry Crews billet stroker crank replaced the factory unit, while the block was fitted with custom liners, torque plate honed and clearanced to accommodate the wide stroke made by the crank and rods. strong Oliver billet steel 5.850-inch rods mate to Bill Miller Engineering forged and dry film-coated 12.5:1 pistons with Childs and Albert Tool steel rings. Rod needed to replace the factory cams with new Crower hydraulic .465-lift bumpsticks. The final cubic inch tally was an impressive 421 cubes topped with a 63mm throttle body, a ported plenum and injector housing (crafted by Greg Van Deventer), a forced air intake, and a LPE Samco intake hose. A direct port Nitrous Express feeds the cold stuff into the chambers, pushing the pony count up to 600-plus horsepower whenever Rod so desires. Since this is all-new technology, a progressive nitrous control module, a wide-band O2 sensor with a data log, and a Doug Rippie customized computer controller with a personalized tune for Rod's combination were needed.

Though, the experience of rowing one's gears is unmatched in the sense of interconnectivity between the driver and machine, Rod knew there was much to be said for an automatic's prowess on the dragstrip. A GM 4L80E automatic with a Compushift "stand alone" computer took the place of the factory MN6 manual six-speed crash box. Rod documented his '91 ZR1 as the second to ever have undergone such a conversion, citing Lingenfelter Performance as the first when they married one to a twin turbo'd ZR1 years earlier. Controlled by a TCI shift kit with a 3,000-stall with a three-disc lock up, the 9-inch Precision Industries torque converter can nearly snap your neck when launched at full load. The telltale sign of the conversion is present in a B&M Mega Shifter poking out of the center console. A custom C-beam housing had to be created for the conversion. Instead of the factory IRS, DeWild Performance installed a Dana 44 rear with steep 4.11 Viper GTS gears and billet spindles. DRM coilovers and shocks at each wheel lowered the black ZR1 into the ground, while Rod skips between 15x311/42 skinnies and 18x911/42 HRE's up front when he's not racing and 15x11-inch Weld Racing rims and 18x12 street meats out back. Since the tech guys at any NHRA-certified track are sticklers for the necessary safety equipment, Rod installed a DRM rollbar and rear bracing.

Corp_0703_06_z 1991_corvette_ZR1 Interior 2/13

Shift
The B&M Mega Shifter is the only giveaway that this ZR1 is touting a heavily rebuilt 4L80E automatic transmission. The rest of the cabin is covered in factory dressings.

Rod and his father, Norm, are the DeWilds behind DeWild Performance in Henderson, Colorado. Dedicated to building some of the best performance engines in the Rockies, Rod has tinkered on several trick rods and street machines, including a custom '40 Ford with a 448ci small-block Chevy with Nextel Cup cylinder heads and plenty of plumbed nitrous, and a fearsome '92 GMC Typhoon with a stroked 383 pushing a stout shot of squeeze.

Rod laughs off inquiries about his ZR1's current streetability, saying he uses it as a daily driver when he's not at the drags. With the old 415 stroker, the inky-black Vette ate up the Beech Bend Raceway quarter-mile in 10.6-seconds at 131 mph. Official times haven't been made since the implantation of the 421ci quad-cam stroker, but with all the goodies-with or without adjusting for the nose-bleed altitude-it will happily smash that time with cold, mechanical enmity.

One thing is for sure, Rod DeWild's '91 ZR1 eats musclecars with a knife and fork.

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