This is the Corvette that Dave Hill and his Corvette engineering staff don't want to know about. The C4s, built from early 1983 (as an '84 model) 'til mid-1996, were former chief engineer Dave McLellan's creation, while Hill gets credit for the '97 and newer C5s. Some folks inside at GM have told us that McLellan deserves more credit for the C5 than he's been given, but that's another story entirely.
Autocross, or Solo 2 in SCCA, is a unique form of competition. You have to drive around on an artificial course that's usually set up in a giant parking lot. You're racing against the clock, not against other cars, and a lap lasts less than a minute. If you think of an autocross as a qualifying lap in racing, you're pretty close. There's no chance to relax and very little opportunity to think about what you're doing.
Driver ability and a good handling car are the important things for winning in autocross. It also helps for your engine to have a lot of low-end torque and to be hooked to a solid-shifting automatic transmission. When you're driving through cones on narrow courses, wide cars and long wheelbases are hindrances to getting the best time. Early ('84-90) C4s are 176.5 inches long and 71 inches wide on a 96.2-inch wheelbase, while C5s are 179.6 inches long and 73.6 inches wide with a 104.5-inch wheelbase. The same width and long wheelbase that makes a C5 roomy inside and exceedingly stable at high speeds makes it awkward and unwieldy on a tight and twisty autocross course.
The old '85 to '87 Corvettes seem to rule the autocross courses around the United States. These old C4s flat beat everything that's come out of Chevrolet since the mid-'80s. When you look at the SCCA National Championships, you'll always find some of these old torque monsters in the standings.Roger Johnson's yellow '86 is one of the best of these unbeatable autocross Corvettes. It's so competitive that a couple years ago some members of the Corvette engineering team invited Roger and his '86 to the Milford (Michigan) Proving Grounds so their boss could see a real, winning autocross Corvette. Some of the team thought it might be useful if they could get a handle on why this old C4 was able to blow away the brand-new C5s. Of course, it blew away the new Corvettes, right on Chevrolet's home turf.
This yellow '86 is a legend amongst the autocross fraternity. While no one is sure if it's the driver or the car that is great, Johnson's driving ability is something that every Corvette owner who's ever run an autocross aspires to. On the other hand, most autocrossers would like to have his car.
There are several reasons that the '85-87 C4s make wonderful autocross cars. The old L98 just can't be matched for bottom-end torque-it'll damn near pull stumps out of the ground. The LT1s, LT4, LT5s, LS1s, and LS6s are all great horsepower engines, but each and every one of them lacks the raw low-end grunt of the old Tune-Port Injection 350. Fifteen years of technology has produced some great engines, but none of 'em can match the low rpm power of a well-tuned L98.
Roger's car, which he bought brand new, only has about 5,000 miles showing on the odometer. The first thousand or so was on the street. The rest is a lot of Solo 2 runs, a whole lot if you consider that the average run is usually well under one mile, and lots of times closer to a half-mile.
In late 1987 the folks at Chevrolet convinced Roger that the new '88 Corvette with its re-designed, zero-scrub-radius front suspension would be the way to go. He even put the yellow beast up for sale while he prepped a new '88 version. Roger was serious about the '88's prep, so the car was sent to C4 performance guru Kim Baker for special attention. The late John Lingenfelter was made sure that all was perfect within the engine.
There was only one problem. The brand new 1988 Corvette couldn't match the times of the old '86. Nothing that Roger did would make the '88 Corvette competitive with the yellow '86. If Roger Johnson, Kim Baker, and John Lingenfelter's combined expertise couldn't make the '88 run as fast as the older car, all hope was gone. Fortunately, no one had come up with the required cash to purchase the "old car" so the "For Sale" signs were taken off the '86 and placed on the '88. It was back to Old Yellow.
Roger has tried C5s but feels that they have major limitations for competitive autocrossing. A great many other Corvette autocrossers apparently agree with him, as you seldom see a C5 at autocrosses, other than Corvettes-only events. Some have tried, but few have succeeded, except with Z06s, at the SCCA level of competition.
The one thing that Roger Johnson has proven is that if you start off with the "right" car, stick with that car, and develop it, you can have a winner. While most of us try the latest trick part of the week, or maybe even the trick car of the month and stay also-rans, Roger just keeps running up the miles on his old yellow '86, and keeps right on winning.
Here's an interview that someone else did with Roger Johnson. Very interesting. He talks about how all of his Corvette engines were blueprinted.
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