In the late ’60s, Dodge was desperately looking to get more speed out of its Charger race cars so it could turn around its fortunes on NASCAR’s super-speedways, and knew more horsepower wasn’t the answer.
So engineers there began experimenting with the car’s aerodynamics instead, to make it more slippery-through-the-air. After months of testing, they settled on adding an 18-inch pointed nose cone and two-foot-tall spoiler.
It looked outrageous, but it worked.
The race car, which Chrysler called the Charger Daytona, won its first-ever NASCAR event and helped Dodge dominate the circuit the next two seasons. In March 1970, it became the first stock-bodied car to crack 200 miles-an-hour (320 km/h) on a closed course, at Talladega.
The effect of those mods in terms of actual down force and drag figures was never properly measured—until now. When offered access to UOIT’s ACE Speed Lab wind tunnel in Oshawa, Ontario, we knew what we wanted to do with it—use it to find out exactly what the Daytona’s wing and nosecone really did.
And so we set up a comparison between a 1969 Dodge Charger Hemi; an authentic Charger Daytona; and, just for the heck of it, a 2015 Dodge Charger Hellcat. Here’s what we found out.
The Hunt For Five Miles-An-Hour More
Chrysler Corporation started toying with aerodynamics in the ’30s while developing its streamlined Airflow, but it wasn’t until the mid-’60s that they looked closely at how to better move air around a vehicle. In April 1968, Chrysler’s Space Division sent a report to its automotive engineering offices suggesting they use wind tunnel testing in mainstream car development.
Wind tunnel testing – which involves measuring how air moves around a vehicle by putting it, or a scale model of it, in a long tunnel with a wind-generating fan – was by then becoming a common way to evaluate air- and spacecraft design, but was all but unheard of within the automotive industry.
Still the auto engineers gave Chrysler’s rocket scientists an ear. They had just that year debuted the second-generation Dodge Charger, a car heralded by many as the best-looking Chrysler ever produced, but that they were beginning to understand was a disaster aerodynamically.
While the stylish machine was okay on the street, on NASCAR’s high-speed banked-corners race tracks, up at around 180 mph (290 km/h), drivers complained the steering felt light and twitchy.
And so by mid-1968 Chrysler was firming up wind tunnel testing plans with the goal of bettering its Charger race cars’ lap speed by five miles-an-hour, something that would’ve required 50 to 85 additional horsepower but could also be achieved by reducing aerodynamic drag 15 percent, engineers figured.
A Plymouth race car being lowered into the Lockheed wind tunnel. The Lockheed tunnel, previously used to test scale
aircraft, was accessed via a hole in the ceiling, through which cars had to be lowered nose-first.
(images from Greg Kwiatkowski via AeroWarriors.com)
Chrysler would conduct the tests using 3/8-scale clay models in the Wichita State University wind tunnel; and, later, full-size cars in aircraft manufacturer Lockheed’s larger wind tunnel in Georgia.
Before long they had initial results that pointed to Charger’s problem areas—the “flying buttress”-style tunneled rear window; the recessed front grille area; and the windshield-to-side window transition over the A-pillar.
And not long after that they had a solution—a plug that made the rear window flush with the rear pillars; a flush-mounted grille swiped from the Coronet; and chrome metal covers for the A-pillars. They effected all of these changes on a new trim called the Charger 500, which wind tunnel testing suggested should’ve topped out at 194 mph (312 km/h).
The Birth of the Super Charger
That wasn’t fast enough for the speed freaks at Chrysler. They sent the 500 out on the racetrack while they continued working on the Charger in the lab.
At some point, after someone lifted all the restrictions head office had imposed on the engineers, aerodynamicist John Pointer came up with a strange pointed nose cone and huge rear spoiler kit for the car, which he mocked up in cardboard and duct tape on a real Charger and tested at Chrysler’s Chelsea Proving Grounds.
The rough pieces seemed to help, and so fibreglass molds were pulled off of them and scaled down for wind tunnel model testing. After a few months, in July 1969, the refined nose cone and spoiler found their way back onto an actual prototype, internally referred to as the “Super Charger,” for real-world testing.
The company’s efforts culminated in a new model called the Dodge Charger Daytona, which NASCAR forced Chrysler to build 500 or so production examples of, for homologation purposes.
The production Charger Daytona built on the features pioneered on the Charger 500 – the rear window plug and the A-pillar shields – but added an 18-inch-long nose cone with undernose spoiler; two 23.5-inch-tall vertical stabilizers on the rear fenders; and an adjustable wing hung between the stabilizers.
(Did Chrysler really jack up that spoiler to almost two feet so it wouldn’t block the trunk lid on the production car from opening?
That’s the rumour, but some aerodynamicists on the program later confided that height was actually required to get the wing into “clean air,” away from the air separating from the rear window.
What we know for sure is that some Chrysler tests involved spoilers six inches and 15 inches above the trunk.)
All of these changes reduced front axle lift, making the car hold to the road better; and alleviated drag, making it easier for the car go to faster.
In fact they helped the car win its first-ever NASCAR Grand National race at Talladega and nab the gold at more than three-quarters of the races it competed in the rest of the season.
Chrysler easily got the added five miles-an-hour they were looking for, and then some.
In March 1970, a Charger Daytona piloted by NASCAR driver Buddy Baker even became the first stock-bodied car to exceed 200 mph [320 km/h] on a closed course, at Talladega.
The production car, built essentially by hand for Chrysler by Detroit’s Creative Industries, didn’t fare so well, however.
Though the outrageous-looking Charger Daytonas won on Sundays, they didn’t sell on Mondays, and instead mostly sat on dealership lots, some until the salespeople manually removed the nosecones and wings.
They were on sale for just a few short months beginning in late 1969, but were replaced in 1970 by the Plymouth-branded Superbird; a ’71 Daytona was considered, but never built.
Fade Paint Jobs And Shag Carpet
The Charger Daytona we secured for our wind tunnel comparison is a little bit—different from most. It’s nicknamed “Discotona,” and comes from the collection of Ontario-based Mopar enthusiast Jim Bodanis.
Discotona was purchased new in New York and, some time around late 1971, was transformed into a “street freak” show car. It had its factory orange covered up with a custom red-gold fade with white scallop-type stripes; and its interior replaced with ’66 Charger pieces and red shag carpet.
In 1979, after several years on the show circuit, Discotona was parked with just 16,000 miles on its odometer. It wouldn’t move again until early 2006, when Bodanis bought it from a pair of classic car brokers who’d recently got it off the original owner.
Bodanis revived the car, going over its mechanicals and shining up its untouched retro paint job. He yanked the custom interior out and in 2013 put its original seats (they were part of the purchase) back in.
Custom paint job aside, the car’s body is generally stock. The large seam between the front fenders and nose cone has been filled in and smoothed over, and the rearward-facing scoops on top of the front fenders have been molded to the body, too, theoretically giving it a slight aerodynamic advantage over an unmodified Charger Daytona. But for the purposes of our test Discotona would do just fine.
Drag, Lift, Down Force And The Principles of Aerodynamics
Our tests would be conducted at the ACE Speed Lab located at the University of Ontario Institute of Technology (UOIT). Their wind tunnel has been used extensively by automakers for product testing, but is open for bookings by race teams, amateur car enthusiasts—really anyone who needs a wind tunnel or wants to make their car go faster.
“We can test things you can’t test anywhere else, because we can do both climatic and aerodynamic in the same facility,” explains Gary Elfstrom, ACE Speed Lab’s aerodynamicist and an industry veteran. “From snow, wind, sun, sleet, dry, cold, as well as aerodynamics [testing]—we can do everything.”
The wind tunnel testing we’d be conducting would be different from the testing Chrysler did back then, Elfstrom explains, largely because the science has come so far since 1969. “What we call computational fluid dynamics they didn’t really have at all back then,” he says. “It was a lot of by-guess-and-by-golly.”
Our tests would be different, too, from those of other modern wind tunnels, which might lock the car’s rocker panels down to a testing rig; ACE Speed Labs instead measures aero effects via sensors under the car’s tires. “[The former] is more of a purist approach, but requires more testing at different ride heights,” says Elfstrom. “Our tests give you the real road feel.”
What we’d mostly be looking at, Elfstrom explained, was lift – and its counterpart, down force – over the front and rear of the Chargers.
“When airflow goes over a body that’s highly curved, it will [exhibit] lower pressure, and tend to literally lift the vehicle up,” he says. “You generally don’t want that—if you get a lot of lift, the car will be unstable. You want it pushing down a bit, what we call ‘down force.’”
We’d also consider aerodynamic drag, which does exactly what its name implies. “Drag is the loss of the energy of the flow as it goes around the vehicle—think of it as dragging the car backward, slowing the car down,” Elfstrom says.
“Drag is [typically caused by] something called flow separation. The airflow tries to keep attached to the surface, but when there’s a lot of curvature, it can’t so it says, ‘Oh, to hell with it!’ and literally leaves the surface.”
1969 Dodge Charger Hemi: The Bouncer
“Oh, to hell with it!” was something the air flowing over our first test car, the 1969 Dodge Charger Hemi, said quite often.
The gorgeous black-with-red-stripe car had belonged to Ontario’s Wayne Boland for just about a year when we tested it. It boasts a lightly-tuned-and-dressed Hemi V8 under the hood but, more importantly for our purposes, looks relatively stock outside, save for a slight nose-down stance.
The ’69 would act as our benchmark, so we tested it first, driving it into the tunnel and centering it over the sensors. When it was ready, we got out of the tunnel and into the control room to run it up.
Within seconds, the air in the tunnel was moving at some 100 km/h (62 mph), and from there was gradually ratcheted up in 20 km/h increments to 200 km/h. Elfstrom pointed out trends in the data projected on the computer screens. “[Rear] down force hasn’t increased that much with speed. The front lift has gone up,” he said.
At around 140 km/h and up, we noticed something the numbers couldn’t show us: the rear end of the car bouncing more and more on the suspension, almost half-an-inch. The effect was caused by air flowing over the roof toward the rear window tucked between the “flying buttress” roof pillars and breaking away or separating, Elfstrom explained.
“It’s unsteady, so it’s shaking the car around,” he explained. “[At near 200 mph, the speeds Dodge’s race cars were approaching] it would be just the same, only worse. The drivers would say it feels very light.”
That flow separation over the rear window, as well as a similarly severe separation over the leading edge of the hood, created both significant drag and lift—“something that was preventing this hot rod from really getting up to top speed,” as Elfstrom put it.
At 200 km/h (124 mph) our final numbers were 373 lbs of lift on the front end and almost 80 lbs of down force out back (keep in mind those numbers don’t take into account the weight of the car, and just represent how much the wind wants to lift the car up or push it down).
We also measured 435 lbs of drag pulling the car back, a number it’d take 144 horsepower to overcome (again, that’s not the total horsepower it’d take to stay at that speed, just how much it’d take to overcome that much drag).
1969 Dodge Charger Daytona: Disco Forever
Next we loaded Discotona into the tunnel and ran it through the same test. It was, in a word, better. Way better.
The Charger Daytona exhibited none of the bouncing the Charger had, though there was a slight sway side-to-side—it’s possible the stock Charger wiggled its butt, too, but the two-foot-tall spoiler made it more apparent.
The numbers at 200 km/h (124 mph) were, as you’d expect, improved. Drag was cut down by a little under 100 lbs, giving the car the equivalent of an additional 30 horsepower. And while we read 200 lbs of lift on the nose – a gain of some 170 lbs of down force – the change in rear down force wasn’t quite so dramatic—we’d merely cut out 24 lbs of lift out back.
While we scratched our heads and looked at the charts, the car’s handler, Mopar restorer Jeff Cabot, suggested something: what if we adjusted the angle of the wing like the race cars?
(The street Charger Daytona’s airfoil rear wings were, like the race car’s, adjustable, so that the leading edge could be tilted some 10 degrees downward and about two degrees upward.)
Restorer Jeff Cabot wrenches on the Daytona’s wing while Mopar expert Todd Savage (foreground) helps adjust the
angle of attack.
The first test was conducted with the wing left neutral, as shipped from the factory. Cabot borrowed a wrench out of the ACE Speed Lab toolbox, loosened the nuts, and pitched the wing about eight degrees down.
During that 200 km/h (124 mph) test, front lift went up slightly to 224 lbs, the equivalent of adding 150 lbs of ballast to a stock Charger’s nose to really plant the tires to the pavement. But down force at the rear went up to about 125 lbs thanks to our wing tweak, though of course it also drove drag up slightly as a result, to 363 lbs. Why?
“Because everything affects everything,” said Elfstrom. “Aerodynamics is not like mechanics. You can’t do something that only affects one thing. It will affect something else, either near to it or far away.”
In this case, the tweak to the wing affected just about everything. When we ran the smoke over it at low speed, Elfstrom was ecstatic. “That’s beautiful! See what it’s doing?” he exclaimed, pointing. “It’s curving the flow! It’s doing exactly what it’s supposed to do!”
After the wind tunnel engineers saw how securely anchored the vertical stabilizers were to the fenders, they also agreed to let us run Discotona up to 250 km/h (155 mph), close to the ACE Speed Lab tunnel’s maximum speed.
That test demonstrated how the relationship between drag, speed and power worked. To sum it up, a car moving at a certain speed needs to use not twice, but eight times as much horsepower to go double that speed. We’d ramped up the wind speed by just 50 km/h (30 mph), but drag went up to 542 lbs, a force it’d require 110 more horsepower to overcome.
Front lift and rear down force was exaggerated at these speeds, too, to 330 lbs and 170 lbs, respectively. On a NASCAR track at 200 mph (320 km/h), the effect of the wing would have been tremendous.
Getting The Inside Scoop
When we listed the improvements Dodge made to the Charger Daytona over the stock Charger, you might’ve noticed we missed something: the rearward-facing scoops over the front tires.
When the race car debuted, these openings confused both rivals and NASCAR officials. Chrysler explained the scoops, which were often metal and blended into the bodywork on the race cars, covered a hole cut into the fender so the tire wouldn’t rub against it when the down force compressed the front suspension at speed.
But the actual function of the fender scoops became, and still remains, a topic of debate.
Wing car website AeroWarriors.com has an entire page about possible purposes for the scoops – to extract heat from the engine bay, for example – along with a chart from the Daytona’s development they say shows the “exhausters” reduced drag three percent.
Chrysler’s official line is still that the scoops were for tire clearance only, but Greg Kwiatkowski, owner of the #88 Dodge Charger Daytona that Chrysler Engineering used for some of its earliest testing, doesn’t buy that.
“That theory is carried on by guys that don’t have a race Daytona to see what is actually going on,” he says.
Kwiatkowski, a chassis specialist for Fiat-Chrysler (FCA), says vintage photos of his car show the tires’ tops would have contacted other underhood bracing before they got close to the holes for the scoops, suggesting they definitely weren’t for tire clearance.
Street Daytonas got the scoops, too, though these production pieces were made of plastic and covered only a very small mesh-covered circular hole cut into the fender-top. If the scoops did improve the aerodynamics of the race car, they almost certainly didn’t for the street version.
We considered blowing smoke around the scoops during our time in the wind tunnel, but Elfstrom suggested their aerodynamic effect likely would’ve been negligible until the car got closer to its top end. But, being an industry veteran, he was able to give us an inside scoop on the scoops anyway.
“[A former Chrysler aerodynamicist] told me it’s very small, [but there is an effect],” he relates. “I don’t know whether it was the intended benefit, but it was one.”
2015 Dodge Charger Hellcat: Four-door Fury
Our last test of the day was of the new Charger Hellcat, one of the first American four-seaters capable of crossing 200 mph since—the Charger Daytona, probably. Like the stock ’69 Charger, the new Hellcat is one hella good-looking automobile, but unlike the ’69, it was designed with aerodynamics in mind.
Engineers with Chrysler’s SRT division spent more than 100 hours in the Chrysler Technology Center wind tunnel in Auburn Hills, in fact, honing the shape of the Hellcat to make it slipperier through the air.
“Both the designers and aero engineers worked closely together to create a vehicle that has a unique look and a lot of visual presence, but also an impressive 206-mph top speed,” said Mark Trostle, head of Dodge and SRT design.
“We worked to ensure the rear spoiler and the front fascia, with its integrated splitter, created the right amount of aero balance (or high-speed stability) while not creating too much drag. It proved to be a challenge to balance the engine cooling requirements needed when you have a 707-hp powerplant with creating the right amount of front down force.”
Versus the stock 2015 Charger, the Hellcat gets a slightly elevated rear spoiler for better down force; twin heat extractors on the hood, just behind a forward-facing scoop for the engine intake; and a revised front grille and chin splitter.
And do they help? Oh yeah. The way the air clung to the car blew Elfstrom away. “It has smooth airflow over the entire length of the car, and you see no major flow separation, which is a big improvement from before,” he said. “It also means at high speed the car is much more stable, too. We didn’t see any heavy shimmying or anything.”
That the Hellcat blew away the stock ’69 Charger from every angle, thanks to its rounded front end and rear spoiler, was really no surprise. What did catch us off-guard was how it stood up next to Discotona.
“Actually, they’re fairly similar,” Elfstrom said, looking at the data on the screen. At 200 km/h (124 mph), front lift was 201 lbs, to the Daytona’s 200; rear down force was about 80 lbs, versus Discotona’s 100; and drag was 354 lbs to the old car’s 345 lbs. The numbers were almost exactly the same despite the 45 years – and differences in scientific understanding – separating the two vehicles.
Graphs comparing, from left to right, the front down force, rear down force and overall drag. The Charger Daytona’s
numbers are with the rear wing angled downward.
Two Hundred Miles an Hour—No Wing Required
As Elfstrom pointed out, the takeaway is that the numbers may be similar, but that the Daytona looks like a cartoon while the Hellcat looks like, well, a family sedan. Because it is.
“Aerodynamics is much more advanced now, it plays a bigger part [in car design], but it’s all done through these subtle changes—I mean, you can’t build a car like that with a pointy nose these days,” he said.
Furthermore, the designers behind the 2015 Dodge Charger Hellcat had to make a lot more compromises on things that the engineers in 1969 didn’t have to think twice about.
“They have to tie [into their design] things like heat management flow, underbody flow—everything,” Elfstrom adds.
That’s not to undermine how incredibly slippery-through-the-air the Dodge Charger Daytona turned out to be. When you consider how rudimentary the science of aerodynamics was close to 50 years ago, the results it delivered in our tests are rather incredible.
We went into these tests at the ACE Speed Lab curious about what it took to get this gorgeous-brick-turned-ridiculous-racecar to the edge of 320 km/h (200 mph), and what that crazy nosecone and wing really did.
And now we know: a whole damn lot.
Endnote: Vindication Via Mathematics
Our wind tunnel tests were some of the first conducted on the production ’69 Charger Daytona since rival Ford allegedly purchased and tested a car in the early ’70s.
Chrysler wind tunnel test photo via DodgeCharger.com
The only other record we could find of a Daytona wind tunnel test was a photo from one Chrysler conducted themselves in 2012 in their testing centre’s aero-acoustic wind tunnel, to celebrate the facility’s 10th anniversary.
While the test – of one of the ’69 Charger Daytonas from the Walter P. Chrysler Museum – was initially supposed to be “confidential,” FCA’s since de-classified the aero numbers it returned.
When they sent them to us, we were pleased to see their results – especially the coefficients of lift front and rear – were incredibly close to ours—“almost within experimental error,” as Elfstrom put it.
Talk about vindication via mathematics.