Nov. 1, 1997—Callaway stylist Paul Deutschman's full-sized clay model is approved. With team members scattered across the globe, Internet communication across time zones accelerates development. Callaway Cars' president Reeves Callaway: "We were able to assign tasks based on who was most capable rather than who was most convenient and actually turned what used to be a disadvantage—the geographic and cultural distance between our team members—into the advantage of working nearly 24 hours a day."
November 1997—All-new body panels will have to fasten to the original car's frame. Likewise, new suspension and a bigger brake package will have to fit in the space that the original systems had occupied. Pro/ENGINEER automated product modeling software is used to generate designs.
The car is widened to the full two meters allowed in international racing by custom making the A-control arms. Consequently, the steering geometry, the rear camber and caster adjusters and the driveshaft all have to be changed or redesigned. The team also needs to design the enhanced suspension and brake packages. Three-dimensional models that observe the fixed reference points are used with a range of visualization, assembly and motion programs to make sure that the new systems fit onto the pick-up points of the frame. Interferences are spotted and fixed before anything is built. Callaway: "For each prototype we didn't have to build, we saved several weeks."
Dec. 1, 1997—A laser scan of the clay model is completed and e-mailed to Lepage Design's Stephane Lepage, who begins finishing the "digital clay" with Deutschman. The software package from Parametric is used.
December 1997—The hourglass shape of the clay model was too pronounced; a more subtle flow of the door into the front and rear fenders is needed. Lepage makes the change to one surface and the software automatically updates the rest of the model. LePage: "You can build surfaces that are driven by curves and splines, and even by parameters and formulas. When you modify these, the surfaces are modified too, and the design process becomes very supple."
Dec. 24, 1997—Modeling of the car body is completed. To prepare for manufacturing, Lepage uses the software tools to quickly add features, such as return flanges to the body panels, and to ensure fit by trimming, removing gaps and revising dimensions.
At 9:00 am, the first IGES file with data for the car's door arrives in Germany. The IVM staff imports the data into an in-house program, which creates CAM programs. The first completed door panel exits the mold within 48 hours of the data's arrival.
January 1998—Manufacturing the rest of the composite body panels goes smoothly and quickly; no molds have to be reworked.
March 3, 1998—The Callaway C12 debuts. In the wake of a successful project, enthusiasm is high for new challenges. Callaway: "The feeling in the automotive industry is that no-one is willing to go from the screen to the tool without seeing the thing in three dimensions, but we're getting there."
|The Callaway C12: Anatomy of a Supercar|
|Specifications||Front engine, rear drive, two-seat coupe|
|Frame||Torsion-resistant hydroformed steel frame|
|Body||Exterior skin made of GRP/Kevlar hybrid composite|
|Suspension||4 wheel independent suspension system with upper and lower A-arms|
|Brakes||Internally ventilated four wheel 355 mm disc brakes with ABS|
|Top speed||188 mph (302 kph)|
|0-60 mph acceleration||4.3 seconds|
|Engine||Aluminum alloy, 16 valve, 90° V-8, 5.7 L|
|Bore/stroke||99 mm / 92 mm|
|Rated horsepower||440 bhp @ 6300 rpm|
|Maximum Torque||415 ft-lbs @ 5200 rpm|
|Transmission||Rear mounted 6-speed manual transmission|
|2.66:1, 1.78:1, 1.30:1, 1.00:1, 0.74:1, 0.50:1, 2.90:1|
|Rear axle drive ratio||3.42:1|
|Measurements||Length 4,852 mm; Width 1,998 mm; Height 1,192 mm|
|Wheelbase/wheel track||2,660 mm/1,650 mm|
|Curb weight||1,480 kg|
|Tires||Pirelli 295/30 ZR 19|