Peter Brock and the Daytona Coupe
If necessity is the mother of invention, then genius is the father.
The necessity was created out of the need to win on an international scale. The 289 Cobra roadsters were winning big on American circuits. For the most part, the Shelby American team members grew up in USAC racing. On the short USAC tracks, acceleration won races. They all understood that acceleration is achieved with high horsepower and low weight. The lightweight and very powerful 289 Cobra roadsters fit this model to a T and they were happy with it the way it was.
But the American circuits were shorter and top speeds were significantly lower than their European counterparts. The World Manufacturer’s Championship was contested for the most part on the longer and faster European circuits and the blunt shape of the Cobra roadsters made them non-competitive. If the World Manufacturer’s Championship was to be captured, a significant increase in straightaway speed would be needed. Something would have to change. But what?
The genius was provided by a young automotive designer named Peter Brock. His interest in automotive aerodynamic history while a designer at General Motors equipped him well for the challenge. Peter’s thinking diverged from the rest of the team. He understood that a high top speed on a long straight would be determined more by high power and low drag than by high power and low weight. At 375 horsepower, the stock block Ford 289 V8 was near the limit of its reliable power potential. The answer would not be found in the engine compartment.
Peter knew that the solution could only be found in reducing aerodynamic drag. Drag is directly related to a car’s frontal area and the sleekness of the shape. The drag coefficient, or Cd, is a measure of the sleekness of the shape. The change, as Brock envisioned it, would have to be dramatic. Changing frontal area didn’t offer much of a possibility since the body was already wrapped pretty tightly about the mechanicals. The needed improvement would have to come through a dramatic change in the overall shape.
In the FIA world at the time, there were two essential categories: Prototype and GT (Grand Turismo). The prototypes were just that, limited production experimental cars. They did not require “homologation”, official acceptance by the FIA as production cars. The GT classes were for production cars and the homologation rules at that time required that at least 100 examples be produced before the car could be accepted. Prototypes are typically faster, being closer to all out racecars.
The challenge to the manufacturers has always been in keeping their GT cars fresh and competitive, without making changes that cause the FIA to view them as completely new designs requiring re-homologation.
Ironically, Enzo Ferrari himself masterminded the loophole in the FIA regulations that Peter needed. Ferrari’s beautiful but rather blunt 250 GT Berlinetta had by 1961 reached its aerodynamic limits. He needed the FIA’s blessing to drop the sleek and stunning GTO body on his Berlinetta chassis without being required to produce another 100 copies of the new design needed for homologation. To get it, Ferrari lobbied for the creation of Appendix J in the FIA rules. In brief, Appendix J stated that you could change the body or change the chassis, but not both. Appendix J was intended to cover relatively minor tweaking of an existing body shape in order to allow a small manufacturer to revise an existing shape to conform to slight engineering changes, like new tire sizes or a slightly changed front-end to accept new lighting or cooling requirements. The official wording in the rules referred to a “normal evolution of type”. But the rules were rather vague; there was in fact no limit to the scale of the change allowed. And Ferrari used that loophole to introduce and successfully compete with the legendary 250 GTO.
Peter realized he could exploit the Appendix J loophole to maximum advantage by creating an entirely new coupe body on the existing 289 roadster’s chassis. He presented his ideas to Shelby and was given a guarded go ahead to proceed, provided the project it didn’t take any resources from the team’s mainstream efforts.
After reviewing Peter’s proposed drawing on the project, most of the Shelby team members thought Peter was nuts and kept a polite distance. But Ken Miles, a highly respected driver and development engineer from England, understood what Peter was up to and lent his considerable influence in convincing Shelby that the project was worthwhile.
The blunt nose of the Ferrari 250 GT SWB Berlinetta presented the same aerodynamic problems that the Cobra teams faced.
The sleek Ferrari 250 GTO on the 250 GT SWB chassis was Ferrari’s solution.
The rare and extraordinarily valuable original Daytona Coupes, seen here at the 2003 SEMA show, are far more at home today in museums and car shows that on the road or track.
Still, none of the team’s regular fabrication team wanted anything to do with the project. Only John Ohlsen, a young mechanic from New Zealand, was interested. John was a temporary hire and had yet to be accepted into the tightly knit Shelby organization. They were relieved that Ohlsen could be assigned to the project leaving them free to continue work on the team’s other racing cars. So, in the beginning Brock, Miles and Ohlsen were the only ones involved in the construction of the first coupe. The design objectives were to wrap the skin tightly about the existing mechanicals to reduce frontal area, make it sleek to slice through the wind, and most importantly meet the FIA regulations for details such as windows, windshield, spare tire, and the like. Pete’s personal challenge was to make it aesthetically pleasing, a difficult task, as no one in the shop had ever seen anything like what Brock had proposed and were rather unwilling to change their minds.
The biggest departure from conventional design came in the rear of the car. Theoretically the most efficient aerodynamic design would be to bring the rear of the body to a gradual point, much like an aircraft fuselage. But that would result in a car that was far too long to be practical. The prevailing practice was to use far sharper closure angles to bring the body’s rear section down almost to a point. These sharp angles caused flow separation and high drag.
While working at GM Peter had discovered an interesting technical paper, written in the late 1930’s. It pertained to automotive aerodynamic research attributed to the German aerodynamicist, Dr. Wunibald Kamm. This obscure treatise suggested another approach to reducing drag. In simple terms, Kamm’s technicians recommended the use of shallow closure angles to keep air flowing along the rear body’s surface, and then sharply truncate the form where practical. The airflow would form a “virtual tail” behind the truncated body and provide almost the same low drag as a long tapered body.
Plywood bucks, built on an existing Cobra roadster chassis by Brock and Ohlsen, were taken to Cal Metal Shaping in downtown Los Angeles for construction of the large hand formed aluminum panels from which the body would be constructed.
The believers were few and the skeptics abounded. Vindication came on test day, February 1, 1964, at the Riverside track near Los Angeles. On its first time out, the bare metal coupe driven by Ken Miles shattered the team’s previous lap record by three and a half seconds. Aerodynamics, as it turned out, were incredibly important. This car would be a winner.
The coupe’s competition debut came some three weeks thereafter at the 2000 kilometers of Daytona. In number of entries, the new Ferrari GTO dominated the field, but the sole coupe ran off and left them all. At about the two-thirds point the coupe was 5 laps in the lead, when a disastrous pit fire took it out of contention. It had, nevertheless, shown the world that there was a new international player in the game and it was really quick, quick enough to embarrass Ferrari’s latest and best offering. After Daytona, the press began to call it the Daytona Coupe and the name stuck. The Daytona Coupe faired better at Sebring in March, taking its first win in the GT class.
The competition then moved to Europe. By then Ford had discretely agreed to back Shelby’s bid to win the World’s GT Championship. The plywood body buck was sent to Carrozzeria Gran Sport in Modena, Italy (Ferrari’s back yard) where the other five coupes were built. The first of the Italian coupes, CSX 2299, was built before Peter arrived to supervise. It was modified by the Italian craftsmen, who believed they were “improving” on Californian’s design. They, like the members of the Shelby team, had never seen a car with such a radically shaped tail and thought they were correcting a mistake! They added an additional two inches of headroom in error. This turned out to be somewhat of a blessing as it allowed Dan Gurney’s sizeable 6’2” frame to ease into the very snug cockpit that had originally been designed around a much smaller Ken Miles. The error was corrected for the remaining coupes.
Both roadsters and coupes were campaigned in Europe during the 1964 season, but as expected the coupes showed their advantage on the longer courses.
The first European win came at Le Mans in June of 1964 with Bob Bondurant and Dan Gurney taking first in GT and fourth overall. The two coupes entered were so fast that they left their GT class competitors in the dust and were running among the faster prototypes. Boundurant was amazed by the reaction of the French people. They were captivated by the beautiful body (how French) and the raucous V8 engine (how American) thundering down the long Muslanne straight. Everywhere he traveled in Europe after Le Mans, he was greeted as a hero and a celebrity.
After Le Mans, it was victory after victory. Unable to beat the all-conquering Daytona Coupes on the track, Ferrari tried to get his mid-engined 250 LM Prototype homologated as a GT car. With only a handful of cars in existence, the FIA rightly refused. In retaliation, Ferrari then pressured the Italian organizers of the Monza event to cancel it, depriving the Shelby team of an almost certain victory and the points that would have carried them over the top. When it was all over and the dust settled Ferrari won the World Manufacturer’s Championship in 1964 by the narrowest of margins. But everyone, including Ferrari, knew that the Daytona Coupe was the class act of 1964 - an amazing performance in its first year out.
Shortly thereafter Ferrari announced he would not compete with a factory GT team in 1965. He knew he could not win and channeled all his energy into the Prototype category. Privateers would carry Ferrari’s GT banner.
Ford and Shelby had turned their attention to the emerging GT-40 program leaving the Alan Mann racing organization from England to manage the Cobra effort in Europe for 1965. Under Mann, the dominance by the Daytona Coupes in the World Manufacturer’s Championship was absolute and complete. The Daytona Coupes took 1-2, 1-2-3, or 1-2-3-4 in eight of the ten races. The 1965 championship trophy was easily won.
In a final competitive hurrah, the original coupe CSX 2287 was taken to Bonneville in November 1965 for a series of land speed record runs. Configured just as it had completed its racing career and with no special preparation, it set a Class G record at 187 mph and set a total of 23 USAC/FIA world speed and distance records.
The striking shape of the Daytona Coupe was never tested in a wind tunnel and its drag coefficient - the measure of aerodynamic efficiency - never determined. But the Bonneville run gives us the most accurate measure of the top speed of a particular car and engine under known atmospheric and altitude conditions. From this data and some rather complex mathematics, I calculate the drag coefficient to be 0.29. Wow! This is as good as modern automotive designers have been able to do for the most aerodynamic of modern cars with computer aided design, wind tunnels, huge budgets, and a strong directive to reduce drag and improve fuel economy.
The 1964 season began with a single Daytona Coupe, the 1965 season with four. In all, only six were produced. It is amazing that such a small number of cars could have such a significant impact on the world of motorsports competition and on worldwide automotive design.
As beautiful and as successful as they were, the Daytona Coupes were forgotten at the end of the winning 1965 season. Ford wanted no part of a design that would threaten its GT-40 on the track, so Dearborn’s contract with Shelby stipulated that the Daytonas would be abandoned. Ford went on to great success with the GT 40s.
After the end of the 1965 season, Shelby and Ford had no interest in the Daytonas, so they were left to languish in Alan Mann’s shop. Mann threatened to dump them in the North Sea off the coast of the England rather than pay a huge tax penalty that would be due if the cars remained in England. They had been brought in under bond with the agreement that they would leave England after the 1965 season. Somehow the accountants figured out that it would be cheaper to fly the cars home rather than pay the tax or the cost of their destruction at sea. So they were returned to Los Angeles where they were initially advertised for sale for $8,500. Most sold in the $4,000 to $5,000 range and it was several years before all were sold. Since Shelby had moved on with Ford’s GT-40 program, no attempt was ever made to produce a street or competition version for sale to the public.
In the intervening years, the world has come to value the Daytona Coupe’s legendary shape and winning ways. Today, the six Daytona Coupes are each worth millions of dollars.
Above article from secondstrike.com: http://www.secondstrike.com/Coupe/Brock.htm
Max GOT a trophy
Originally Posted by chachee52
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