Batmans bat-shit crazy Can-Am
Written by Jack Passey | 25th October 2024 | Car Tales
The shadows. Like any good horror movie, is where the beasts Emerge. Monsters so wild they've hidden themselves from mere mortals for years. Created long ago in the early 70's, they've been biding their time, and now… they've returned.
If you say the word shadow to 90 percent of people with even a vague interest in cars, it will most likely mean nothing. Perhaps it's before their time, or just too obscure for them to have seen. But Shadow Racing Cars were giant slayers, a single David among many many giants. Racing in all disciplines of motorsport from Formula 1 to Can-am, the latter is my main focus today.
Can-am is much like the title of this article, utterly batshit crazy. No holes barred, all out, unregulated crucible of fire. It’s motorsport boiled down to its very essence. Want to run a carbon fiber body? Of course! Titanium chassis perhaps? Why not! What engine would you like? who cares, have whatever you like! As long as it has a windscreen of course. Group 7 had arisen as a category for non-homologated sports car ‘specials' in Europe and at first pumped out a fairly modest 600-700bhp. However within eight years the cars were producing more than double… think of a Lotus Elise S1 with a scramjet.
The Can-am Shadow story doesn't start until 1968, four years after the start of the series. Don Nichols moved to California and founded Advanced Vehicle Systems (AVS). The cars were named "Shadow", no doubt a reflection of the owner’s affinity to the character from the comic series “The Shadow” from the thirties. He was shortly introduced to Trevor Harris, a young designer with ideas that could only have been imagined in sci-fi movies. Together they embarked on their first Shadow project, the MKI. Which confusingly would have multiple variants, looking completely different with only a nickname to distinguish.
The brief from Trevor's own brain was to fit the largest, most powerful Big-block V8, into the smallest possible chassis. This is something many designers have tried over the years, however Harris's idea on how to achieve this was hardly conventional and with Don's blessing a full size scale model was commissioned. Now if you've seen a picture of any Can-am car they're wide, so wide in fact that only the Americans could have thought of it. The knock on effect of that was the frontal area. Sure they looked sleek but it took an awful lot of that V8 power to push them through the air. As a result Harris's idea was to reduce that area by up to 35%, not only needing to design a whole new chassis but more importantly tyres. Now small tyres have appeared on many cars but the point here is they owe their aero ideas regarding tyre size, to the MKI. Firestone gave their expertise to the project, Nichols had 10 inch front and 12 inch rear racing tires made, which were 11 inch wide in the front and 16 inch in the rear. They were designed to withstand well over the theoretical top speed of 250 mph.
Another part to suffer from the drastic attempt to get the aero in check was the suspension. No conventional suspension would even come close to sliding its way into that bodywork. What was the solution to this? I hear you ask. Make it smaller? technically, yes but what if the answer was more suspension? Each corner was fitted with three springs, making for a total of 12 springs, and each in turn operated by rocker arms. That's an awful lot of bounce for no damping, and no damper would ever fit this setup. That job was left to sets of compact friction dampers.
Due to Trevor's obsession with the shape there were no obvious mounting points for radiators. Bear in mind even in F1 radiators still remained stubbornly at the front. It wasn't for another three years until Chapman moved them to the side, first on the Lotus ‘72. Why not mount them there? Well due to the size of the engine and it's fuel economy, two enormous tanks sat either side of the engine (health and safety gone mad i tell you). To achieve the shape required a pair of twin water/oil radiators were placed behind the rear wheels to make everything as low as possible.
Harris and the MKI are responsible for many new innovations, often attributed to other manufacturers much later on. For example Centrifugal brake cooling fans on the front wheels, attributed to Porsche in the same series! Most things were adopted to the 917/30 in 73.
Air Brakes by means of movable flaps are thought to be births of the modern age. Not so. Much like the original Porsche 917, movable flaps were installed to assist with the braking, especially with the tiny wheels meant tiny brakes. However a change in the regulations outlawed all movable aerodynamic aids, so these airbrake systems were never finalized. Before I waste the rest of your day, other innovative ideas such as… *deep breath. Slimline Induction system, extreme lay-down driver position, two horizontal pedals: brake pedal left, throttle pedal right. Clutch by hand lever, cable operated gear linkage and modular chassis sections for easier dismantling
Now that's an awful lot to test. So test it they did. Late in 1969 and 1970 the car hit the track at Riverside and Laguna Seca respectively. Two different specifications were tested between Parnelli Jones and George Follmer. At Riverside a Streamliner specification was taken out, with a lack of a rear wing but more noticeably no Slimline Induction. Instead being replaced by a constant Flow Hilborn/Kinsler fuel injection system, coupled with some good old fashioned ram air trumpets. (See above). However at Laguna Seca a rear wing was added, Helping to improve the car's natural rear instability. (See below)
Due to lack of time and aerodynamic experience, the team could not resolve the cooling problems which occurred during the track tests. Extensive Modifications were made, however even though the Shadow Mk 1 showed very competitive pace in practice, it still had to retire with overheating in the following races.
At the start I mentioned there were multiple types of MKI's. While car #1 which is the car you have so far seen was nuts, it culminated together in car #2. First seen at Mid-Ohio 1970. Taking all the knowledge learned from the first car, this almost takes the crown for being the craziest Shadow
Nicknamed the “gokart” which I think we can all see why, was the car to finish the remainder of the season. I say that but they never actually bothered turning up for seven of the ten rounds, so this would be its first and last outing. And what an outing, it wasn't… much like the first car, it proved to be blisteringly fast all throughout practice. While qualifying it set a time of 1:31.4, good enough for 7th! Before you all bash that result, you must bear in mind the McLaren were still top dogs. With multiple cars and the fastest drives from all disciplines; so not so shabby from the Shadow. After just nine laps however, the car was retired due to horrible wheel balancing. So after just three rounds and a Grand total of 46 racing laps, the Shadow MKI Can-am dream for 1970 was over…
Until 1971. Batman's always got more toys.