Tuesday, August 26, 2014

NASCAR wing car development (by Curtis Redgap)

Excerpted from Curtis' excellent article on Chrysler's NASCAR efforts
The answer to more speed was to cut the aerodynamic drag. The answer to that was already sketched out by two different designers independently of one another. The amazing thing is that their respective designs had the nose of the proposed car nearly the same! The rear wing on one design was a two stage affair, while the other resembled the final result of the proposed Dodge Charger Daytona. ...
window inserts

Plymouth made their commitment to build a winged car. Their own version. This was based on Richard Petty's commitment to return to Plymouth to drive that creation. ... Someone thought that doing the Plymouth version would be easy. Just send a Belvedere two door over to Creative Industries Inc., where the Dodge Daytona for the commercial street market had been built. There they could hang a sloped nose and rear wing on the Plymouth and go racing with it. Having to build 2,000 cars for commercial sale prior to January 1, 1970 didn't leave Plymouth much time.
Dodge Charger Daytona - at Daytona Speedway

The aerodynamic engineers warned Plymouth that it wasn't going to be anywhere near as easy to get a winged car with the Plymouth. Scoffing, Plymouth went ahead and had Creative Industries hang a nose on the front and put a wing on the rear of a stock Belvedere. It was awful!
When they saw what Creative Industries had done, the styling department they threw a fit. Faced with having to build 2,000 cars since NASCAR had upped the ante to get in, commercial acceptance was vital. Something had to be done and done quickly.
1970 superbird

A proposal to hang a Charger front clip on the Belvedere was quickly rejected. The two body styles were vastly different. Trying to tinker with the current Belvedere fenders just didn't work out. Wind tunnel testing showed that by doing that, it actually increased drag!
don white

They also had a problem with the rear window on the Belvedere, which was causing a large drag on the rear of the car. Engineers had the means to cure it, but the surgery to do it stuck out like a sore thumb on the roof. They had some money for development, but to cure the rear window drag would have meant changing the entire rear quarter panels, the rear deck lid, the roof sail panels where it sweep into the truck, and leading edge of the rear window where it went into the roof, the rear window itself, and the back valance where the trunk lid locked down. Essentially, a whole new car. No way, said the top management.

Instead, they concentrated on the rear wing. In the end, the side stabilizer part of the wing were 40% larger than the Daytona. The wing was swept back further, and the stabilizers titled in towards the trunk more. The front "beak" of the Plymouth cut into the air at a slightly higher angle than the Daytona. The front air inlet was redesigned to stop any overheating problems. In the end, what had been achieved without redesigning the entire car was a 99.5% stability rate with a small increase in drag. It was not quite as clean as the Daytona. The numbers looked excellent.dodge daytona
... Coronet front fenders and a Coronet hood were grafted on the Belvedere body. The lines were the same, but the Dodge was more aerodynamic. Once that decision was achieved, it took only a week to clay in the entire car and get that model into the wind tunnel. With results coming in that looked decent, two weeks later a fully operational car was off and running at the Chrysler Proving Grounds at Chelsea. Having achieved that, then the prints and materials were sent over to Creative Industries where the street commercial Plymouths were built. Just prior to that, the model designation was changed from Belvedere to Road Runner SuperBird!

No comments:

Post a Comment