Rear Wing

Like going on a strict diet, sometimes you have to make a concession or two and step outside typical guidelines. The ongoing focus for Big Red is to keep the look of the car as original as possible. That’s what RJ likes, and that’s what has attracted fans over the decades. The overall design of the large rear wing is a huge help with drivability, which equates to safety at high speeds. The functionality of the factory spoiler runs out at way before 200 mph. The rear wing creates downforce on the rear of the car, which equates to increased traction at the rear tires. The sides of the rear wing keep the air flowing over the center panel of the wing. When the air spills over the sides, it creates aerodynamic instability and unsafe drivability. An important part of the overall design was to conform to SCTA rules and to keep the rear wing self-contained to the real estate of the trunk lid. Doing so allows the ability to unbolt the four bolts that attach it to the trunk hinges and easily swap a different trunk lid with a smaller spoiler. Dave started by creating the side panels out of 0.090-thick 5052 aluminum. He added a flange to fasten to the trunk lid, and then mounted them equally spaced from front to rear, which made it easier

to fabricate the hinged element in the center of the wing. The round bar between the side panels is what the hinged center section rests upon. The bar can be raised to increase downforce or lowered to decrease it. In these pre-wind-tunnel test images, there are five adjustment holes. Later, a higher sixth hole was added for increased downforce when it was discovered that they could add more downforce without creating unwanted drag. There are two rows of holes drilled from right to left across the trunk lid. The smaller holes are for mounting the piano hinge for the center flap, and the larger holes are access holes for tightening the hardware on the flap-side of the hinge. 

Dave preferred to bolt the hinge directly to the trunk lid, rather than using Nutserts to attach it. Through-bolting the hinge is stronger with an important safety item like the flap; this way, the hinge mounted flush to the trunk lid. Since the center flap rests on the bar between the side panels and it’s hinged on the trunk lid, the design allows the flap to flip over and rest on the trunk lid if Big Red ever spun around at 200-mph plus on the slick salt at Bonneville or on the loose lake-bed silt at El Mirage. Doing so keeps the panel from becoming a big air scoop and creating lift,

which could cause the car to flip up in the air. The spoiler extends nine inches off the back of the trunk lid. The underside of the flap is braced to keep it rigid. The trailing edge also has a half-inch high 90° aluminum brace/wickerbill that spans the width of the flap to give extra strength and create a little more downforce.