Wednesday, December 20, 2006

NASCAR Aerodynamics: A Short History

Amid all the controversy over the Car Of Tomorrow, it's worth looking back at the history of NASCAR aerodynamics, especially when one considers that the modern aerowars of NASCAR dated back 40 years ago this past season.

In 1966 NASCAR's factory wars had hit a rough stretch following the Chrysler boycott of 1965; the 1966 season would be marred by a Ford boycott. At Daytona Speedweeks, though, the Ford and Mopar contingents were out in full force following Dan Gurney's Riverside victory in the Wood Brothers Ford. Richard Petty dominated the 500 and this began a strong comeback year for Chrysler's Motor Parts division after the '65 boycott.

Largely unnoticed at that time, however, the 1966 Daytona 500 saw the introduction of a new bodystyle that would ignite a war of aerodynamics that would rage on and off for decades thereafter. The 1966 Dodge Charger was quite different from the other bodies campaigning the 500 - the nose was flatter than the other brands and the roofline and trunk area were one single sloped piece. The Charger campaigned primarily on big tracks, and in the first half of the season the car proved unstable. By the Firecracker 400 NASCAR had allowed Dodge teams to fit a tab, about two inches in height, to the rear deck to trap air onto the trunk area and thus stabilize the car. This rear spoiler proved valuable as Sam McQuagg drove Ray Nichels' Charger to victory.

Leeroy Yarbrough won the National 500 in Jon Thorne's Charger and Buddy Baker drove Ray Fox's #3 Charger to win the 1967 National 500; most Mopar big-track wins, however, still came with Plymouths, notably Petty Enterprises victory in the 1966 World 600 with Marvin Panch and three wins at Darlington with Richard Petty; Tom Friedkin's #14 Plymouth meanwhile added a dramatic comeback win in the 1967 600 with Jim Paschal.

Though the Charger was hardly a dominant car, its aerodynamic sleekness was directly copied by Ford for the 1968 season. Ford debuted fastback Ford Torinos and Mercury Cyclones, sporting the exact same body shape of the Charger 500 but with narrower side windows. Ford fought long and hard all season with Mopar and dominated the superspeedways; only the two Charlotte races, won by Buddy Baker in the Fox #3 and Charlie Glotzbach in Everett "Cotton" Owens' #6, went to Mopar that year; both were won in 1968 Dodge Chargers, sporting longer noses and flatter trunk areas than the '66-7 Charger.

When Richard Petty switched his Plymouth team to Ford for 1969, Chrysler went to work to reclaim the superspeedways, and in September came out with the most famous aero warrior ever to hit stock car racing - the Dodge Daytona, a shark-nosed high-winged monster that easily set new speed records. The Daytona ran four big-track races in late 1969, winning the boycott-marred Talladega 500 (Richard Brickhouse in the Ray Nichels #99) and the season-ending Texas 500 (Bobby Isaac in the Nord Krauskopf-Harry Hyde #71).

Chrysler then built Plymouth's twin to the Daytona - the 1970 Superbird, sporting a slightly wider nose than the Charger. Intended almost entirely to win back Petty, it succeeded, and Petty got the backing to run two cars on big tracks. Pete Hamilton bested David Pearson in the Daytona 500, then swept Talladega. Richard, meanwhile, recovered from a spin to win at Rockingham, then dominated Riverside, then took down wins at Trenton, the Dixie 500 at Atlanta, and Dover in the Superbird. The Daytona, meanwhile, won the Atlanta 500 with Bobby Allison in Mario Rossi's #22, the Yankee 400 at Michigan by with Charlie Glotzbach in Ray Nichels' purple #99, and the Southern 500 by Buddy Baker in the Cotton Owens #6.

But the 1969 Talladega boycott continued to affect the sport in 1970 because the speeds involved on the speedways was a major factor in that boycott; it was after testing in mid-summer that Bobby Allison, Bobby Isaac, David Pearson, and Paul Goldsmith suggested a power restrictor for carburators to slow the cars. At the Yankee 400 NASCAR debuted the restrictor plate, run on all tracks the rest of that season and on and off until mid-1974.

Ford's decision after 1970 to withdraw from the sport led to Chrysler's drastic cutback to two cars in 1971 and abandonment after that. NASCAR also restricted the winged Mopars to running 300-CID engines in hope they would be abandoned. The 1971 Daytona 500 nonetheless saw Mario Rossi campaign a Daytona with Dick Brooks as driver, and the car fought for the lead and came home in the top ten despite wreck damage. NASCAR then banned the winged cars outright; only on USAC's stock car tour did the winged cars continue; among wins for USAC winged stock cars was Roger McClusky at Pocono in 1972 in a Plymouth Superbird.

Even without the winged cars, though, the aeroization of the sport by 1971 had been astonishing. 1969 Mercuries were campaigned by most Ford teams while Mopars had the 1971 Plymouth Roadrunner or Dodge Charger, both arguably the best balanced cars aerodynamically, with the Dodge having a slight edge due to a sleeker nose. Between the bodies and the use of restrictor plates, the draft that had been notably less effective in the previous four or five years came back with a vengeance, seen in 48 official lead changes, an all-time motorsports record to that point, at the '71 Daytona 500. The draft was also effective at the new Ontario Motor Speedway two weeks later as the lead changed 28 times officially and more than that unofficially.

Charlotte Motor Speedway president Richard Howard, however, introduced a new angle in May with a 1971 Chevrolet driven by Charlie Glotzbach. The Chevy, built by Junior Johnson after he'd liquidated all his Ford equipment, bore some aerodynamic resemblence to the Plymouth Roadrunner and was competitive out of the gates, leading 70 laps at the World 600 and campaigning 13 races that year, winning at Bristol.

The 1970s were for the most part devoid of major aerodynamic changes. Chevrolet evolved into the common means of competitive transportation by 1975, and in that year a subtle change was made, as the slope-nosed Laguna S3 debuted at the Daytona 500 and won with Benny Parsons and the L.G. DeWitt #72 team. Used most often, though, was the notch-back mid-70s Monte Carlo, whose greater frontal resistance compared to cars like the Laguna or even the 1974 Dodge Charger provided a handling edge on the majority of tracks.

The late 1970s did see a significant aerodynamic change. For the 1978 season NASCAR banned the Laguna S3; it also allowed teams to campaign Chevrolet engines for the 1977 Oldsmobile Cutlass 442 and Buick Regal and Lesabre. The Western 500 at Riverside that January was a smorgasboard of body styles including Olds Cutlasses, '74 Dodge Chargers, Chevrolets, 1976 Mercury Cougers, and the 1978 Ford Thunderbird campaigned by Bud Moore's #15 team. Cale Yarborough won the Western 500 in an Olds and said, "The Olds is quite a racecar."

The Cutlass sported a distinctive twin-nostril grille on a sloped, slightly rounded nose, making it the sleekest car on the speedway. The Regal and Lesabre meanwhile sported a sloped grille not unlike that of the Laguna S3, but with flusher headlight covers. The Ford Thunderbird was similar in styling to its Mercury cousin but much bulkier.

For Dodge, however, the only choice available was the 1978 Magnum, featuring a notch-back, sloped headlights, and a large protruding grille. Parts supplies for Dodge teams were drying up by then, and in preseason testing the Dodge's handling sent up a red flag - "The Magnum is undriveable at 190," Richard Petty said in January 1978. Drivers of the Olds Cutlass said the same thing - "I can't drive the Olds, it moves around too much," said Donnie Allison that January. For the Cutlass, a major problem was the open rear quarter windows, which many said packed air inside the sloped rear glass.

For Daytona Speedweeks spoiler sizes were incrementally increased to add some stability, and the racing proved to be competitive. The 125s were won by A.J. Foyt in a Buick and Darrell Waltrip, driving a '76 Monte Carlo because "it's a proven product." The lead bounced around back and forth, sometimes four times in one lap, in the Twins, and Waltrip edged Petty in the final lap of his Twin where the lead changed hands twice - Waltrip after the Twin stated, "Richard Petty has the fastest car here," but in the 500 Petty pulled a three-car draft away from the field only to blow a tire and wreck out at Lap 60. For the 500 Bobby Allison won in Bud Moore's Thunderbird, using a handling edge to pull away from the sleeker Olds Cutlasses.

Complaints about instability caused NASCAR before the Atlanta 500 to add over an inch to the size of rear spoilers, and for the next three seasons the aero wars were a sideshow to the overall on-track competition. The Olds Cutlass won two Daytona 500s, the 1979 Atlanta 500, four of six starts at Talladega, and the 1978 Michigan 400, to go with a plethora of short track wins by Yarborough in 1978. By mid-1979, though, Cale had switched to the Monte Carlo for short tracks and intermediate supers, as the Monte Carlo proved a better handler than the slicker Cutlass - thus were NASCAR teams acquiring an understanding of downforce, though it would be much later that the term, and understanding of it, became a major componant of the garage area.

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It was 1981 that an even more pivotal aerodynamic change was made. NASCAR mandated a complete changeover to 1981 bodystyles with 110-inch wheelbases, a change that turned into a running controversy as almost no bodystyle of the time was stable enough to race - proven in graphic fashion by a series of airborne melees at Daytona in preseason testing and preliminary racing before the 1981 500.

NASCAR increased spoiler sizes to over five inches in height by the start of the 500, which helped keep the cars on the ground. It also cracked down on the one bodystyle suited to racing, the 1981 Pontiac Lemans, a slope-backed racer campaigned by Bobby Allison and Ranier Racing and which dominated Speedweeks before losing the 500 on fuel mileage. By the Atlanta 500 the Lemans was allowed less than three inches of spoiler, and the car was effectively stricken for the season after that. Buick Regals all but monopolized victories, while the tank-like 1981 Ford Thunderbird pulled down seven wins that year, enough to help persuade Ford to reenter the sport for 1982, while Pontiac did the same.

Chevrolet soon followed, and debuted the flush-nosed Monte Carlo at Daytona Speedweeks 1983, a car that quickly replaced the Buick Regal as the common means of competitive transportation. Ford, meanwhile, did even better, debuting the raindrop-shaped Ford Thunderbird. Sporting a very rounded nose and roofline, the style owed more than a little debt to the '81-2 Pontiac Lemans that had caused so much controversy in the 1981 Daytona 500. Fords won four times in 1983 and again in 1984, but it was 1985 when Bill Elliott and Melling Racing exploded into prominence with their Thunderbird, campaigning a car that likely was 7/8ths scale, as the car proved undraftable almost everywhere and racked up 11 superspeedway wins; only a total collapse in the short track portion of the season's final third stopped Bill Elliott from an easy 1985 championship.

But that success detonated a new aero war in 1986. Buick and Oldsmobile stepped up their NASCAR efforts with slope-backed cars, Chevy debuted the Monte Carlo with radical sloped rear glass bolted onto the trunk area, and Pontiac came out with the even meaner-looking Grand Prix 2+2, sporting a flush grille and enormous sloped rear glass. Computer engineering also began entering the sport in a big way, and the long-time practice of "raking" a car's aerodynamics took on greater importance as rooflines and other areas of the cars began to get ground down and slickened more.

This combined with escalating horsepower to increase speeds well past 200 MPH, and a series of airborne melees tore up a lot of cars until Bobby Allison ripped out 100 feet of frontstretch fencing at Talladega in May 1987. NASCAR tried smaller carburators for the two remaining races at Daytona and Talladega that year, only to see Ken Schrader flip into Harry Gant and almost into the fencing in the trioval in the Firecracker and then Brett Bodine get upside down at Talladega in late July.

With the aero wars came a noticable weakening of the draft, which was now affecting ability to pass as the drafting wake off of a car that had been over 300 feet in the early 1980s had by 1987 shrunk to less than 100 feet. NASCAR now mandated restrictor plates for its two largest superspeedways for 1988, and spoiler size began to increase again as GM debuted its GM10 bodied racecars, rounded machines such as the Chevrolet Lumina. By 1993 spoilers had grown to 6.5 inches in height, and at that year's Daytona 500 it helped make drafting more effective, to where the lead changed hands 38 times officially and Dale Jarrett, driving for second-year team owner Joe Gibbs, gunned down the Lumina of Dale Earnhardt in one of the greatest Daytona 500s ever seen. The bigger spoilers also helped improve the draft a tracks like Charlotte, where the World 600 proved to be a spirited race-long battle, and Pocono, where that July the lead changed two to three times a lap on at least five seperate laps.

Speeds, however, were escalating even more, between horsepower, aerodynamics, and the introduction of radial tires during the Goodyear-Hoosier tire war of 1988-9. A series of airborne melees hit the sport in 1993, and when rookie Johnny Benson tumbled down Michigan's backstretch that August, NASCAR tested Ken Schrader's car with a restrictor plate at Charlotte. The plate was 1.25 inches in diameter, larger than that used on the big supers, and did not slow the car used by more than five MPH. Other drivers lobbied against using the plate, recommending instead that spoiler be reduced to five inches in height and the front airdam be raised to five inches off the ground. The reasoning was that the bodystyles were making so much downforce that corner speeds were too high; reducing downforce, so the argument went, would force drivers to lift for the corners and thus slow the cars. This became known as "the 5&5 rule," and in its first race, the National 500 at Charlotte, it failed spectacularly - the cars proved unable to close up on each other and Ernie Irvan, driving Robert Yates' Ford, led almost the entire race, the worst runaway at Charlotte since Leeroy Yarbrough's runaway win in 1966.

The 5&5 rule was quietly dropped after 1993, but in 1998 it came back, and was run for the entirety of the season. In the interregnum, meanwhile, Chevrolet came out with the 1995 Monte Carlo, a rounded, muscular bodystyle deliberately built with downforce as a primary goal. A controversial change to the car's rear deck allowed it to destroy its opposition in 1995 en route to 21 wins, but it also led to a precendent in NASCAR circles - after the Atlanta 500 in 1995 NASCAR confiscated one model of each competing make and tested them in Lockheed's windtunnel, this after Ford lobbied ferociously about the Monte Carlo. "(Billy) France felt like the manufacturers had lied to him," noted Shaun Assael in Wide Open: Days And Nights On The NASCAR Tour, and when they provided aerodynamic numbers he didn't understand, it was the final straw - he now determined that NASCAR would set the aerodynamics of the cars, not the manufacturers.

Windtunnel testing now became a norm of NASCAR and a series of spoiler changes came to equalize the three makes involved in the sport. Ford was eventually allowed to lower the MN12 Thunderbird's roofline and came out in 1996 with a flusher nosepiece, eventually going from eight wins in 1995 to 13 in 1996 and 17 in 1997; in the process they won 1997's manufacturer championship, one of six they'd win over the period of 1992-2002.

Pontiac, meanwhile, came out with a new Grand Prix in 1996, but the car teethed badly in its first year; initially submitted to SABCO Racing in latter 1994, the Grand Prix was to have been built for testing by March 1995, but SABCO refused to build one and eventually Petty Enterprises and Bahari Racing built the prototype, the project losing six months of lead time. The Grand Prix's unique aerodynamic characteristic was its twin-nostril nose and also its rear deck, sloped upward at the taillight areas and downward in the middle, an interesting approach to reducing drag without sacrificing downforce. The Grand Prix needed a new nosepiece by June of 1996, but broke through to win at Phoenix with Bobby Hamilton and the #43, and when GM switched Joe Gibbs' team to Pontiac for 1997 development of the car accelerated; in 1999 JGR and its two-driver tandem of veteran Bobby Labonte and rookie Tony Stewart erupted to eight wins while John Andretti and the Petty #43 rallied to win Martinsville and he and teammate Kyle Petty combined for some 18 top ten finishes. Also making noise that year was Ward Burton and the Bill Davis #22 Pontiac, contending almost everywhere for top tens.

As for the draft, it made a mini-resurgence in the 1995-6 period. "Drivers were telling me, 'Man, I can't believe what the draft's doing now,'" Ernie Irvan said during World 600 weekend in 1995; this was reflected in a hotly contested 600 and also a pair of hotly contested Pocono races in which the lead changed multiple times a lap on several occassions.

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The aero wars took a few new twists in the early portion of the 21st century. The most spectacular twist came when NASCAR tested several cars with a strip across the roof and a wicker on the rear spoiler, designed to add drag and slow the cars down more. This roof spoiler package was tested in the summer of 2000 and debuted at Talladega in October 2000; the Winston 500 turned into the most exciting and celebrated race ever seen as the draft became unstoppable and the lead changed hands 49 times among 21 drivers. This package ran on the plate tracks in 2001 with tentative plans to begin integrating it onto other tracks after that, but the death of Dale Earnhardt and a massive wreck at Talladega in October 2001 set off a surge of driver demands to eliminate the roof spoiler package. NASCAR dropped the roof spoiler after that, though it came back for the Busch Series' plate races in 2004 and again proved supremely effective in improving the competitiveness of the racing.

The longer term twist came in 2003 when NASCAR mandated a basic aerodynamic shape for all makes, a process called aero-matching by NASCAR but more derisively referred to as common templates elsewhere. Following a 2003 season in which Ryan Newman won eight races and did so on several occassions by not pitting under late yellows and stretching his fuel, NASCAR cut spoiler to five inches for 2004 and less than that for 2005, in yet a third edition of the 5&5 rule, this after ferocious lobbying by Ryan Newman's erstwhile teammate Rusty Wallace. NASCAR involvement in the aerodynamics of the racecars then reached an ultimate degree with the design of the so-called "Car Of Tomorrow," a design-by-committee hybrid of a racecar and a racing Truck sporting a grotesque gap in the front airdam, a raised roofline, squared body, and wing on the rear deck.

The COT has tested throughout 2006 and has proven unraceable everywhere it has tested, but NASCAR to date has publically made clear it will campaign the car beginning in 2007. Whether this timetable actually comes to fruition remains to be seen (Robin Pemberton's recent denial of a report that NASCAR would delay introduction of the model comes across as the sanctioning body putting out fires instead of a believable response) as another chapter in NASCAR's aerodynamics history opens.

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