1974 Shadow DN3

Don Nichols was very familiar with innovation in the automobile industry. This led Nichols to become very influential in the Far East and gave rise to many theories about his life.

Nichols founded Advanced Vehicle Systems and called his cars Shadows; using the rumors swirling around his mysterious life to good effect. While Nichols; himself, possessed an innovative mind, many of those innovations didn't quite work well in reality.

As a racing team, Shadow first became involved in Can-Am racing. Working with his designer Trevor Harris, Nichols helped to create an innovative car. It proved to be quite quick, but wasn't matched by reliability.

Heading into 1972, the team's first design was reworked and actually improved a good deal. This was helped to some degree by the fact it was a titanium car. By 1973, Shadow grew to be one of the more competitive teams in the dying Can-Am series.

At the end of 1972, due mostly to the fact Can-Am racing was dying, Nichols announced Shadow would begin taking part in Formula One. Nichols had been able to secure the talents of Tony Southgate, who had previously worked for BRM, to design the grand prix cars for Shadow.

Southgate's first chassis, the DN1, was quite aerodynamic in its shape and featured some lovely flowing lines. The car proved to have potential, enough anyway to convince Graham Hill to purchase the chassis for his Embassy Racing team. However, the car proved to be quite fragile.

Unlike the DN1, the DN3's lines were not as flowing as what they had been. It would be very hard to tell that the DN3 evolved from the DN1 when the new car was finished and debuted in 1974.

The nose of the car remained low-slung, like on the DN1, but the design was much different. The low, flat nose remained, but quite different than before. The DN1 utilized a contoured plane in its nose design. It looked more like a wing element than a nose, and, would be used as such. This was because the top of the nose contoured upwards as it travelled aft toward the cockpit. The low, flat nose blended into the single-plane front wing seamlessly. Incidentally, it would be in the nose that the car's small battery would be located. The spar running through the front wing would attach to the front of the tubular support structure for the nose.

The nose on the DN3 was quite different. The nose remained low and flat. It also featured a lip design that blended seamlessly into the leading edge of the single-plane front wing. However, a channel was cut into the nose of the car. The nose bodywork also bulged slightly due to the channel cut into it. Southgate had designed a feature that would end up being taken and used in Formula One and Le Mans prototype design into the early 21st century. One of the changes between the DN1 and the DN3 at the back of the car would lead to the channel in the nose of the car.

Radiators were mounted underneath the rear wing on the DN1. These radiators would capture the air flowing around the engine and would help with the cooling operations of the car. In the search for better aerodynamics, these large radiators were taken away. The design of the car was such that there wasn't any place to put these radiators once they had been removed from the rear of the car. The solution was to place smaller radiators in the nose of the car where it would receive a lot of airflow. This led to the channel in the nose of the car.

Ram air entered the channel and into the radiator. This air needed to be extracted so the cooling operations could remain efficient. This led to the slot gap designed into the nose a little further back. The air flowing over the lip of the bodywork covering the radiator would cause a low pressure above the slot gap and would pull the hotter air out through the radiator. This would also go to help pull more air in through the channel at the front. This aspect would be an important feature utilized some thirty-five years later. Instead of being used for cooling operations, this slot gap would be used in designs for the purpose of using the nose to provide extra downforce. The air being pulled out through the slot gap actually pulls the nose down to the track, increasing downforce.

The bodywork aft of the slot gap was similar to that of the DN1. Both the DN1 and the DN3 featured 'ears' in the bodywork to help cover aspects of the front suspension. However, these 'ears' were much more pronounced on the DN3. On the DN3, the bodywork 'ears' extended outward and upwards a bit more than on the DN1. This provided a leading edge for the airflow to blend around and not get all that disrupted by the suspension components.

As with most of the chassis designs of the period, the actual tub structure underneath the car's bodywork was an aluminum monocoque frame. The bodywork served to make the car more aerodynamically efficient. Since the aluminum structure mainly served as a crash structure and a mounting point for the outer bodywork, the bodywork would serve to give the car its actual shape. This meant the driver sat down inside the actual wide-open structure of the car and the bodywork would then surround the driver. It would be similar to a go-cart with a body.

Because the bodywork served as the aerodynamic structure of the car, the driver's cockpit was tight, especially around the shoulders. The driver sat tall in the car. In order to make the design as aerodynamic as possible, the bodywork rose sharply. A monocoque metal roll structure served as a mounting place for the cockpit's instruments and gauges and for a place to rigidly mount the steering column. It was contoured inward along the sides to provide a solid structure of the contoured bodywork to rest, but it also featured a rounded top to do the same for the bodywork rising up to surround the driver in the cockpit.

Because the bodywork narrowed as it rose upward, the area down around the driver's waist was actually quite wide. Therefore, some of the lines and components would be visibly run through the cockpit. One of the more obvious things seen in the cockpit included the line running to the radiator in the nose.

Only a few analog gauges adorned the cockpit. Most prominent in the driver's view was the rpm gauge that turned with the 10,800 rpm Ford Cosworth DFV V8 engine. Power from the 465 bhp engine was delivered to the rear-wheel driven DN3 by a Hewland 5-speed manual gearbox, which was able to push the car from zero to 60 in only 3.1 seconds. The short-shifting lever was located to the right of the steering wheel. Because of its location, and the need for the driver to get his hand on it, the bodywork needed to be built with a bulge in it. When looking at the bodywork from the outside it is noticeable that the bodywork bulges out just as it begins to rise upward. This was to provide room around the gear lever.

Behind the small padded headrest, the car's main roll structure protruded out of the top of the bodywork. This tubular roll-hoop featured other support tubular framing to add stiffness and strength.

Smoothly flowing from the bodywork 'ears' that helped to cover some of the front suspension components, the bodywork begins to widen as it travels back along the side of the car. This is not a steep angle, but one that obviously widens as it heads aft. This led to an upper and lower leading edge. This would help to direct airflow into the small sidepods located well back along the sides of the car. Located in these sidepods were other radiators important to the cooling operations of the car. The internal bodywork helped to direct and speed up the airflow to maximize efficiency. The upper portion of bodywork was one greatly contoured piece that included the surround for the cockpit, but also, the top of the front suspension 'ears' and the upper leading edge of the car's radiator sidepods.

One interesting design feature of the car came with the location of the engine. The Ford Cosworth DFV engine was merely bolted onto the back end of the car. Once bolted on, the engine served as a part of the stressed structure of the car. This meant other parts could be attached right to it. This would include the airbox that fed into the induction pipes for the V8 engine.

The 90 degree Cosworth engine was able to sit low in the car, which helped to lower the car's center of gravity, thereby improving handling characteristics. The induction pipes for each of the cylinders were positioned in between the cylinders in the middle of the engine. Since the engine was normally aspirated, it was important to get air into the engine to produce the 465 bhp possible. The best way to do this was to fashion an airbox that would capture the air and direct it into the engine. Unlike the design used in the DN1, and that of today, Southgate created a tall airbox that extended up in the clear flowing air above the roll-hoop. The DN1, and modern designs, incorporate the airbox and the roll-hoop into one single structure in an effort to forge more aerodynamic efficiency.

The bodywork extended aft only to cover the radiators in the sidepods. The area around the top of the banks of the cylinders was left open. This was mostly due to clearance issues. The rear suspension incorporated twin trailing arms. The upper trailing arm actually attached to the car's structure up near the front of the engine. To ensure the trailing arms were able to move up and down without impedance, there was no bodywork fashioned to cover the engine banks.

Besides the trailing arms, the rear suspension was created in a similar fashion as the front. The rear would utilize coil springs mounted at an angle to provide rear wheel ride control. The rear brake discs were mounted inboard, meaning away from the wheel itself, as the area was already well-occupied because of the suspension components and the drive shaft. Mounting the brakes inboard helped to deal with an important issue in an already busy area of the car. That issue was rear brake cooling. By mounting the brake inboard, the discs were outside of the wheel hub itself and had access to cooler free air. This helped to cool the brakes.

The area between the suspension members was also made more complicated by the presence of the V8 engine's exhaust pipes that ran just below the coil spring and between the drive shaft and lower suspension arms. These single pipes that exited to either side of the gearbox was a blend of an exhaust pipe from each cylinder. They blended together right underneath the coil spring.

The rear wing was simple and straight-forward. It was quite deep and ran to the inside of the rear wheels. The rear wing was one, large plane that was mostly flat in its camber on the top. The bottom; however, featured a tall camber to help produce downforce. A single central structure attached the rear wing to the structure covering the gearbox. Additional stringer posts ran out to points out near the endplates for additional rigidity. Over the course of the season, an upgraded wing was made available. This utilized a twin-plane design, instead of just one single plane.

The cars of the day featured wide rear tires that were great for sliding the cars through the turns. Though easy to break loose because of the power, the 60 inch rear wheelbase made the car comfortable while drifting. The 58 inch front wheelbase also helped to make the car feel stable.

In 1973, the Universal Oil Products (UOP) company came on as Shadow's main sponsor. When the new DN3 car was debuted it did so with its black paint scheme and white UOP letters adorning the cockpit, airbox and rear wing. The improvements over the DN1 became apparent right away. At the first race of the season, the DN3 was able to turn a lap fast enough during qualifying to start the Brazilian Grand Prix 3rd. The car would go on to take 3rd at Monaco.

In spite of the promise, tragedy would come knocking on Shadow's doors during the third round of the World Championship. Peter Revson was at the wheel of a DN3 when he would suffer a fatal accident. As rescuers tried to revive Revson in vain, the DN3 just burned up. The rest of the season also went up in smoke as a result of the tragedy. The very end of the season saw the DN3 revived to new life when Jean-Pierre Jarier was able to take the car to victory at Laguna Seca in October of 1974.

The DN3 would end up taking part in a couple of races in 1975. Then, it would be replaced by the DN5. That was the end of the DN3. Tragedy had managed to kill the potential of the DN3 as the team, and the car, suffered in mourning. However, out of the ashes arose hope. The DN3 would give rise to the DN5, and then, to the mighty DN8—Shadow's most profitable performer. The DN3 was the basis for a future champion. This is what the DN3 should be most remembered for doing.

Sources:
'Shadow DN3', (http://www.histomobile.com/dvd_histomobile/usa/1197/1974_Shadow_DN3.htm). Histomobile. http://www.histomobile.com/dvd_histomobile/usa/1197/1974_Shadow_DN3.htm. Retrieved 4 April 2011.

Wikipedia contributors, 'Shadow Racing Cars', Wikipedia, The Free Encyclopedia, 1 April 2011, 22:14 UTC, http://en.wikipedia.org/w/index.php?title=Shadow_Racing_Cars&oldid=421890507 accessed 4 April 2011

'DN1', (http://img89.imageshack.us/i/dn1.jpg/). ImageShack: Media Hosting Company. http://img89.imageshack.us/i/dn1.jpg/. Retrieved 4 April 2011.

'Cars: Shadow DN3', (http://www.racingsportscars.com/type/results/Shadow/DN3.html). RacingSportsCars. http://www.racingsportscars.com/type/results/Shadow/DN3.html. Retrieved 4 April 2011.

'Shadow DN3 Cosworth', (http://www.ultimatecarpage.com/car/2573/Shadow-DN3-Cosworth.html). Ultimatecarpage.com: Powered by Knowledge, Driven by Passion. http://www.ultimatecarpage.com/car/2573/Shadow-DN3-Cosworth.html. Retrieved 4 April 2011.

By Jeremy McMullen