Calling this 1984 Chevy Corvette fast is like saying Mark McGuire is an OK hitter and Jeff Gordon is a fair driver. This C4 gives new meaning to the word fast. In fact, it lays claim to the title of "World's Fastest Corvette," having been officially clocked at 271.044 mph on the Bonneville Salt Flats.
The Bonneville Salt Flats are located in western Utah, just outside the town of Wendover. It's the site of an ancient lakebed that dried up thousands of years ago, leaving behind a several-inch-thick layer of nearly pure and startlingly white salt. The 44,000-acre Flats are so flat that if a person with good eyesight looks across the surreal terrain toward the horizon, he will actually see the curvature of the earth!
The car's current powerplant...
The car's current powerplant is built around a production cast-iron Mark V 502 engine block and aftermarket Dart cylinder heads. The Bob Creitz-built engine displaces 580 ci and delivers a reliable 1,100-plus hp at 7,500 rpm.
Every August since 1949 a band of speed junkies has gathered on the Salt Flats to test their courage and the mettle of their machines. Under comprehensive rules devised by The Southern California Timing Association, the vehicles are classified according to engine displacement, type of fuel used, body style, and a host of other parameters. Each vehicle is given opportunities to travel down a marked course, where it is timed at mile intervals. If the average of two consecutive runs exceeds the existing record for the class, a new record is established.
Since the late '50s, Corvettes have figured prominently among the vast array of vehicles found at Bonneville. Their excellent aerodynamics, more than anything else, is what attracts would-be racers to the marque. That is precisely what led J. Mindenbergs to build this '84 in the first place. He bought the car brand-new and immediately converted it into a Bonneville record contender, quickly moving from contender to record holder, a position it has occupied ever since. Mindenburgs established a new AA/GT (This is a GT class racer with an over-501ci engine) record in the car in 1988 with a two-way average speed of 266.450 mph. He also took the car to its highest recorded speed thus far, the amazing 271.044 mph mentioned earlier.
This 271-mph Corvette still...
This 271-mph Corvette still retains most of its stock interior, including instruments, door panels, and even part of the carpeting. Added instruments and an on-board DynoLab dynamometer help owner/driver Bobby Moore keep tabs on the Corvette's vital functions.
In 1996, Bobby Moore bought the '84 from its second owner, who had run it as high as 219 mph on the Salt Flats. Bobby had never competed at Bonneville before bringing his Corvette there in 1997, but immediately earned the respect of his fellow racers by reaching 225 mph in his first Flats run. By the time the meet was over he held the new AA/MS record with a two-way average of 234.162 mph. In addition to setting a new class record, Bobby earned another honor by being inducted into the Bonneville 200 mph club. To qualify for entry into this exclusive club one must both run a two-way average speed in excess of 200 mph and establish a new class record.
Bobby returned to Bonneville in 1998 and ran the '84 in the A/MS class, where he set a new record of 236.142 mph. As with the AA/MS class, the Corvette was run as a "Modified Sports" car, which is basically a stock car with the addition of a front air dam and rear spoiler to the original bodywork. The "A" designation in the classification indicates that it ran with an engine displacing between 440 and 501 ci.
For 1999, team member Bob Creitz, a legendary engine builder and member of the NHRA Drag Racing Hall of Fame, built a larger powerplant for the car. The 580-inch Chevy engine put the Corvette back into the AA/MS class, where the current mark is 251.261 mph. Running on 110-octane racing gas, the naturally aspirated, Hilborn-injected big-block makes in excess of 1,100 hp, enough to give it a shot at the record. Unfortunately, it was also enough to blow up the car's Doug Nash five-speed transmission. Without a spare gearbox on hand the car was done for that meet.
"We'll be back," reported Bobby immediately after returning to his pit area. "The transmission broke, so we won't be running any more this week. I'm thinking of replacing the Nash with a Lenco, which is a little bit stronger."
If Bobby was disappointed with his bad luck he didn't show it for a minute. Instead, he immediately turned his attention to the other car he and his crew brought to the meet, a '28 Ford roadster. "Of course, we come out here to try to set records," he said philosophically. "That's the whole idea, to beat the other guy fair and square. Myself and my crew, Larry and Brad Stansbury and Bob Creitz, are all Oklahoma boys and we love to beat the California boys. But in Bonneville having fun is far more important than setting records. There are no prizes or money involved and that's what makes this sport the best. Money would just ruin it. We're here to have a good time, learn all we can about going fast, and share the good times with everyone else who comes out here to run. We're proud of this Corvette, proud of everything it has done and everything it will do. And you can mark my words, we'll be back again!"
Two Deist parachutes comprise...
Two Deist parachutes comprise the bulk of this speed record holder's braking system. The only other things slowing the car down are wimpy drum brakes on the rear wheels and gravity.
Understandably, the Southern California Timing Association (SCTA) has devised a comprehensive set of safety standards that all competitors at the Bonneville Nationals must conform to. Because of its demonstrated performance potential the Corvette must utilize special tires designated for ultra-high speed. Twenty-four-inch front and 30-inch rear Mickey Thompson super speedway tires are more than up to the task. The rear tires, which are speed-rated to 575 mph, are mounted to special steel rims manufactured by Taylor Made Wheels in South Gate, California. These rims are custom fabricated from 1/4-inch-thick steel plate to ensure structural integrity under the most demanding conditions. Up until this point the Corvette has used production GM steel rims in the front, but car owner Bobby Moore plans to replace these with Taylor Made racing rims in the near future.
"We haven't had any problems with the stock rims," he points out, "but the tech inspectors recommended switching over, and given that we're planning to go faster and faster with this car we think it's a good idea to follow their advice."
Inside the car, a fully re-inforced and gusseted rollcage is installed in accordance with SCTA specifications. Besides providing tremendous driver protection, the cage also imparts much-needed rigidity to the car's chassis.
Because the Corvette's body is fiberglass, and because it goes more than 175 mph, a full arm and leg restraint system is used in addition to the typical five-point driver harness found in almost all race cars. The arm and leg restraints prevent the driver's limbs from extending past the rollcage structure, thus minimizing the likelihood of serious injury in a crash.
Fire is a very real danger in any race car, and the Moore & Stansbury Corvette has two onboard fire extinguishing systems, just in case. The first, with a 5-pound capacity, is designed to control a fire in the engine compartment. A larger system, with a capacity of 8 pounds, is intended to protect the driver by directing its Halon charge into the cockpit.
While going fast is the primary function of a Bonneville racer, slowing down is something it must also do well. To accomplish this the Corvette, like almost all Salt Flats competitors, is fitted with rear brakes and a parachute system.
Maintaining directional control on the unpredictable salt surface is a precarious pursuit at best, and the application of front brakes would almost certainly send the car into a spin. Because of this, they're simply left out of the equation altogether. And since rear brakes alone are usually inadequate, the primary stopping tool is the parachute system. The Moore & Stansbury C4 is equipped with two Deist parachutes. The first, called the high-speed chute, is 8 feet in diameter. As the name implies, it is deployed at high velocity-over 230 mph in this case.
Once the high-speed chute slows the car down to about 170 to 180 mph, the low-speed chute is called upon. It is 12 feet in diameter. A final safety item worth noting are the roof rails, which are mandatory in various classes, including the ones this Corvette competes in. The rails, a la NASCAR, are fabricated from lengths of 90-degree angled metal fastened to the car's roof. They don't look like all that much, but in fact they go a long way in discouraging the car from getting sideways at high speeds.
What Makes the Fastest Corvette in the World Tick?
The '84 Moore & Stansbury Corvette has competed and held records in several different classes, including AA/GT, AA/MS, and A/MS. The first letter(s) of the label denotes the engine displacement and the second group of letters indicates the vehicle classification. "A" applies to Otto or Diesel cycle engines that displace 440 through 500 ci, and "AA" applies to those that displace 501 ci or more.
"GT" refers to grand touring cars, a class for production cars primarily intended for comfortable high-speed touring. It includes both coupes and convertibles, and can include cars with rear passenger seats if those seats are so small as to be unsuitable for continuous adult occupancy. In most respects, GT cars are supposed to be typical of street going cars as delivered by the original dealer. As such, very few modifications are permitted.
"MS" stands for modified sports, GT class cars that have had certain permissible aerodynamic modifications. Among these are air dams, nose cones, rear spoilers, belly pans, skirts, and other similar devices. As currently configured, the Moore & Stansbury Corvette is set up to compete in the AA/MS class.
The Mark V-based 580-inch big-block uses a wide array of high-performance components, including a Crane camshaft, Hilborn fuel injection, and Dart heads prepared by Ron's Porting Service in St. Louis. The 14.5:1-compression behemoth makes its peak power and torque between 5,500 and 7,500 rpm.
While the OEM C4 rearend assembly is a strong unit, it is simply not up to the demands this type of car creates. Therefore, it was replaced with a production GM 12-bolt solid-axle assembly originally installed in a fullsize Pontiac. To achieve the speed needed to be competitive the differential is fitted with a 2.41:1 ring-and-pinion. The car's body is modified as allowed by MS class rules. The front nose cone, which Bobby Moore fabricated himself from fiberglass, cuts through the wind better than the stock front bumper and imparts some welcome downforce to the car.
At the rear, a custom fabricated wing assembly also helps keep the car from flying, and aids drive wheel traction by contributing additional down force.
The Taylor Made rear wheels and stock GM front wheels are covered with stylish and functional Moon discs. As you would expect, these spun aluminum covers reduce aerodynamic drag from the wheels to almost nothing. The Corvette's substructure, suspension, and steering are all original equipment. The frame has been considerably strengthened with the addition of the rollcage. Modifications to the suspension including setting alignment specifications to optimize ultra-high-speed stability, eliminating front shock absorbers, adding super stiff springs front and rear, and severely limiting suspension travel. "Our suspension is real tight," explains owner/driver Moore. "Front travel is limited to 1/2-inch and rear travel is only a little bit more at 1 inch. On a rough track this type of suspension can beat you half to death!"
"We eliminate the front shocks altogether," he continues, "because they would encourage the front end to come up and we want it planted and riding hard all the way down. We don't want it moving up and down, because up over 200 mph the car wants to fly if the front end comes up and catches air underneath."
In addition to tightening up the suspension and radically limiting travel, the Moore & Stansbury crew has added a huge amount of ballast to the car. Lead filled steel tubing, steel plate, and even concrete-filled stock mufflers bring the Corvette's weight up to an astounding 6,000-plus pounds! "The extra weight accomplishes several things," explains Bobby. "It keeps the car on the ground when it wants to fly and helps keep it going in a straight line. Also, it goes a long way in getting the car's drive wheels to hook up. The salt can be quite slippery, and breaking the rear tires loose is counterproductive to say the least."
Besides the obvious problem of not accelerating if the drive wheels are spinning, loss of traction can also spell disaster for the engine and drivetrain. As the car hits bumps in the track and some of the weight comes off the rear wheels, and as the wheels hit wet and slippery patches of salt, they spin up very quickly. Correspondingly, the engine and drivetrain spin up very quickly as well, creating the constant danger that some components will be over-revved. To cope with this Bobby relies on an on-board Dyno Lab dynamometer. "The dynamometer has an accelerometer," he explains, "which tells me the rate that the car is accelerating or decelerating. Obviously, we also have an engine tachometer. If the accelerometer indicates that the car is slowing down, and the tach indicates that the engine is speeding up, I know the rear wheels are loosing traction. To get the car back I quickly stab at the brakes without letting up on the throttle. You want to keep your engine rpm up as high as possible, so you don't want to let off the throttle. At the same time, wheelspin can spell disaster, so you've got to get it under control. An old timer who has been racing here for decades taught me that trick. Just a few quick stabs at the brakes and the rear wheels bite in again."
There is a lot more to going fast than simply strapping a big horsepower engine into your car. The car must be extensively modified for safety. And depending on what class you are running in, it also may be considerably modified for improved performance. And the final component in the go fast equation is driver experience and technique. It may look like all the pilot is doing is mashing the throttle wide open and holding on for dear life, but in actuality he is making a constant stream of instantaneous decisions and adjustments that allow him seek glory on the Salt Flats, and live to tell about it.