The Coupe Design

The new Coupe’s round tube space frame chassis is as modern as they come. Bob Negstad and Dan Bamford of Roush Engineering completed the chassis design using the latest design techniques and principles. Wes Schultz of ACT did the finite element analysis. Unlike the original 289 chassis, the Superformance Coupe chassis is quite rigid with a torsional stiffness of 6,000 lb-ft per degree.

The design team decided to extend the wheelbase three inches and to increase length, width, and height proportionally. The longer and wider chassis allowed room to optimize the suspension design. The wheelbase and width are close to Bob’s original design for the 427 before AC shortened it.

Bob, Don, and Wes also designed the fully independent suspension. Wes did all the computer design work using the industry standard ANSYS system.

The front is unequal length A-arms with coil over shocks. The rear suspension features unusually long lower arms that pivot almost at the chassis centerline. This unique geometry allows the rear tires to remain in correct alignment with the ground over a wider range of suspension travel and cornering angles than a conventional suspension. The tires therefore stick better than with conventional suspension geometry. The result is a comfortable compliant ride and outstanding handling, a combination rarely found in any car. This unique design was Bob’s last project. He died shortly after it was completed.

The Body Design

The new Superformance Coupe body shape has been designed to conform to Pete’s original design philosophy for the Daytona Coupe and is also based on the aero-technology that he had discovered while at GM. It is not a recreation of the original design, though. It is a step forward in time.

Brock felt that it was important in resizing the form to retain the key proportions, including the roofline, which was never done to his satisfaction with the original cars.

Front suspension with double A-arms, coil over shocks and vented rotors

Coupe rear suspension in final assembly area showing lower arm with inboard pivot, upper arm, trailing link. Coil over shocks will be fitted where temporary bracket connects frame to lower arm.

Design model - 1997

In 1997, a body was mocked up on a chassis to create a design model as a first step toward production. One of the design models actually had different lines on the left and right sides so that visual impact of the different styling themes could be assessed in full-sized form.

The design model was fitted with Halibrand FIA style rims with the same 255/60-15 front and 275/60-15 rear tires used on the Mk III. The tires filled the wheel wells perfectly and achieved the desired period correct look.

Brock went to the plant in late 1998 to work with Jeremy on refining the body design. Many subtle but significant design changes were made and evaluated. During the course of the car’s design, Brock and Price went through six or seven plugs.

Design changes continued up through the beginning of production in 2003. Many more subtle changes, such as an increased plan view radius for the windscreen, flush side-windows, and subtly re contoured body shape were incorporated to improve the aerodynamics and visual appeal. When Brock was done, there is not a single line on the car that paralleled the original.

The finished design is so natural, it is difficult to image how much hard work went into creating it. But the result is pure genius. To the naked eye, the new car looks to be the same size as the original Daytona Coupe, but it is slightly larger in every dimension, allowing for improved handling through improved chassis design and larger tires and for increased interior space. The shape is so tuned to perfection that an original would look somehow off by comparison.

The Wheels

The design model uncovered a major stumbling block to production. The design team agreed that a Z-rated tire would be needed to match the speed potential of the Coupe. The 15-inch rims and tires looked right, but Z-rated tires in the 60 series were not available. The biggest Z-rated tires at the time were a good two inches smaller in diameter and the 35 series sidewalls were too thin to give a period correct look. Visually, the difference was unacceptable. The Z-rated tires simply did not fill the wheel well.

A worldwide search began for the right tires to match both the performance and the look. The search for the right rubber would delay the project for several years. Such was the seriousness of the quest for perfection. It was not until 2002 that proper tires became available.