For over a decade from the very late 1960s, a man with a varied and mysterious past took the fight to far bigger and more established companies in both Can-Am, Formula One, and Formula 5000.

While success was limited, the elusive backstory of Don Nichols (1924-2017) and the unorthodox approach to design warrants elaboration.

Don didn’t live the hallmark movie upbringing that ultimately brought him into motorsport. From losing his mother in a tornado as an infant to enrolling in the military at high school age, Don found himself leaping out of a plane in Normandy on D-Day as part of the 101st Airborne Division.

The military lifestyle suited Don. He rose through the ranks, becoming a captain following his service in Korea. But after that, things became a little more vague, but infer from it what you will.

Don’s next vocation was military intelligence during the Cold War. Being a man of few words still subject to the Secrets Act meant he gave little away in interviews, but we can surmise with some certainty that Don was a spy.

It was after this that Don started becoming ingrained in the motorsport industry. He became a fixer, facilitating and brokering parts sales through a growing network of contacts. This prowess and dedication garnered him a strong reputation. Some notable achievements included being heavily involved in Fuji Speedway’s development and introducing Mooneyes products to Japan.

The wealth that accompanied the success gave rise to another opportunity. Behind the scenes, his company, Advanced Vehicle Systems (AVS), took advantage of the liberal rules in the Can-Am series to bring something groundbreaking into the fold. The Shadow drew its name and inspiration from a 1950s radio program called The Shadow, which opened with the tagline: “Who knows what evil lurks in the hearts of men? The Shadow knows!” It was entirely befitting of the man who knew many people, but many people knew little about it.

The 2024 Goodwood Members’ Meeting held in May provided a taste of the incredible creations that rolled out of the doors at AVS. But it was my follow-up at Era Motorsport, who supported the cars during their stay in the UK, that I gained some real insight.

There isn’t enough space to talk about all of the cars that rolled out of the Southern California workshop, so we’ll be taking a closer look at four that are significant in their own rights.

Mk1 Prototype

The solid black paintwork of the Shadow Mk1 Prototype is the most reserved part of the car. To the untrained eye, it resembles something out of Wacky Races, with the car earning the nickname ‘Knee-High’ for obvious reasons. Designer Trevor Harris sought to interpret the Can-Am rules in a way not done before, and started by reducing the frontal area dramatically (by 1/3rd) compared to other cars on the grid. This necessitated many more changes, the first being how to get hold of tyres that would fit.

Don’s relationship with Firestone provided the diminutive tyres; 10×11 inches wide on the front and 12×16 inches wide at the rear. The brake discs within the front wheels were turned down from a larger vehicle, while the wheel aero discs started life as magnesium engine cooling fans in Chevrolet’s Corvair.

To help slow the car down, an ingenious airbrake system was designed. Activated by a steering wheel mounted button, two smaller panels rose on air rams ahead of the front wheels, and a larger perforated panel rose at the rear.

Movable panels to help divert air to the rear-mounted radiators were also fitted.

The periscope tube-style intake was an effort to reduce drag, at the expense of a slight power loss.

The relaxed ruleset that gave Harris such creative freedom was heavily revised and altered ahead of the 1970 Can-Am season in which the Mk1 was due to enter. Moving aerodynamic devices were prohibited, which necessitated some dramatic revisions. The Mk1 Prototype was done before it had even gotten started.

Mk1

This provides a convenient segway to another of the cars, the equally outrageous Mk1.

Gone was the long sleek body shape. The extender rear, which previously held the cooling package is no more, with a huge rear wing standing high in its place. An unorthodox solution for the radiators was to mount them on the wing. This was only allowed for one race due to a technicality, with further revisions having the radiators inside the wing aerofoil itself, with the leading edge cut open to allow flow through.

As with the prototype, little consideration was given to leg room, with the driver originally needing to splay their feet out to control the throttle with the right foot and braking with the left. A hand control operated the clutch, but this has since been updated, with the hood blister allowing the throttle and brake to sit on the right and the clutch on the left.

The periscope was also gone, reverting to the more traditional ‘row of trees’ for the intake, finally letting the 427ci Chevrolet V8 motor breathe. The two tapered tubes next to the engine intakes feed cold air to the rear brakes.

Firestone no longer makes the rear tyres, so in their place is a dual setup, running modern Formula car rubber. The fronts are the same as those used on the Tyrell 6-wheeler, given they’re very similar in size.

Success would elude AVS for a while yet, with this car only entering three races, DNF’ing the first two due to overheating issues and barely finishing the third. During this period, Shadow was on the verge of bankruptcy, with law enforcement knocking on the doors one day to seize the cars. Overnight, Don and the team hastily assembled some sham race cars from spare parts, before setting off for the border to race earlier than planned.

Mk3

Through sheer luck and tenacity, Don negotiated a deal to have Universal Oil Products sponsor Shadow from the 1971 season. Money meant more development, or rather experimentation. The Mk2 only had limited success; it was just too different from the conventional (and successful) competition.

A drastic change was required in the form of the Mk3, nicknamed ‘The Conventional One,’ at least by Shadow standards. A modified Mk2 chassis provided the base, with around 50 dramatic changes.

Most notably, 15-inch wheels allow the fitment of conventional tyres.

For an unknown reason, the front brakes remained inboard despite having wheel clearance. A shaft connected the brakes to the front wheels, which needed replacing almost every outing.

The radiators were placed ahead of the rear wheels to mitigate any overheating issues with the engine and gearbox oil coolers aft of the motor.

While this car retained the iconic intake trumpets, the later seasons saw AVS adopt turbocharging so it could keep up with Porsche, McLaren, and the rest of the Can-Am grid.

The Mk3 showed glimmers of competitiveness, qualifying in the top five for all but one of the eight races it entered.

Was the unlucky streak for AVS lifted? No. A slew of DNFs yet again, so back to the drawing board.

DN4

Skipping ahead to the 1974 season, the fuel crisis was in full swing. A rule revision mandated a minimum 3.0mpg fuel consumption rate, something done by limiting the maximum tank capacity. This time around, the redesign yielded a genuinely competitive car.

The 13-inch/15-inch staggered wheels permitted a drastically reduced frontal area compared to the Mk3.

The fuel restrictions meant reverting to a naturally aspirated 8.1L (494ci) Chevrolet V8 engine, which thanks to refinement of the mechanical injection and rotating assembly resulted in outputting close to 800 horsepower towards the end of the season.

Because Shadow had been running cars in Formula 1 concurrently, much of the suspension design had been brought over, with minor adjustments for bodywork dimensions.

Having thousands of miles of testing and development paid dividends. Jackie Oliver drove the DN4 to outright victory in the first four races, beating the competition from McLaren, Porsche, and Ferrari, and ultimately winning the championship.

This would prove to be the peak of the Shadow’s success. Can-Am was no more, with the focus shifting to Formula 5000, which Shadow entered cars into alongside Formula 1. The single-seaters failed to draw in spectators, which resulted in an attempt to later reprise Can-Am by clothing F1 cars in full bodywork under the Can-Am II banner.

Success is lauded long after the moment passes, but creativity and ingenuity seldom attract the same admiration. Don and the Shadow team never reached the highest echelons of success. Pushing boundaries was prioritised, bringing something that, had they had more testing time, could have resulted in a different story being told.

That unwavering determination is something I fear we will never see the likes of again, given how restricted modern motorsport rulesets are.

We often refer to decades past as the ‘good old days.’ In this case, they were just that.

Thanks to Era Motorsport for being so hospitible and owner Jim Bartel for bringing the cars to the UK.

Chaydon Ford
Instagram: chaycore