The Unfair Advantage
So, you and your mate have bought yourself some slot cars to have some fun with over a few beers. He’s a Ford man and you like the idea of racing his Brut 33 Falcon with your HDT Torana, and kicking his butt like it’s 1974 again. But wait. That Scalextric Torana is no match for the Falcon. Why can’t you keep up? When your Torana hits a curve, it trips and rolls over like a Las Vegas hooker. Unlike the heyday of the real L34, the Scalextric Falcon is a better racer, and the reasons for it are plain and simple. The dynamics that help your Scalextric hang in the slot mean that the wider and longer chassis of the Falcon is more predictable in a slide and less likely to jump out of the slot.
The late Mark Donohue was a great racer and car developer. The title of his biography The Unfair Advantage, was indicative of his racing philosophy – get the car set up so that beating the other guy isn’t hard work. In the same way, setting up your slot car can reduce the number of spectacular, carwrecking crashes, and hopefully level the playing field. Set out in this month’s column are some lowkey improvements for the Torana that could make you look like the Harry Firth of slot cars.
The first step is to take off the bodies, and it reveals the essence of the problem for Torana racers. The Falcon has a much bigger footprint on the track and uses a sidewinder motor. The Torana is the same height as the Falcon but much shorter and slightly narrower. It also runs an inline FF motor, which is notorious for its all-ornothing power delivery.
At this point it is a good idea to rotate the rear axle by hand. Check for any notchy or clicking feeling between the gear on the axle and the motor pinion. It could mean mould flashing from the casting, or as commonly seen in older cars by Spanish maker Flyslot, a cracked pinion. In this case the Scalextric ones felt good, however I did detect a significant amount of slop between the axle and the nylon bearings. This allows any imbalance in the wheels and tyres to show up as wheel hop.
Removing the tyres revealed that the outer rim of the plastic wheels has been made with a larger diameter (13.3mm) than the inner rim (12.7mm). It’s only a small amount, but this difference makes the tyre sit up on the outside. This is handy for reducing rolling resistance up front, but at the back it stops the tyre from sitting flat on the track and reduces available grip. The tyres that came with my Torana also had a very square edge. When the car starts to slide at the back, this makes the tyre prone to catching on the track surface. Putting a bit of a radius on the edge makes the slides more predictable.
To smooth things out I decided to replace the entire rear axle set-up. I used Sloting Plus aluminium wheels which are wider, a Slot.it 28 tooth gear, a precision rear axle and metal bearings with lubrication holes. The Slot.it gear has a bigger diameter, so I had to grind a relief in the bottom of the chassis to make room for it. It did leave two small pinholes, which I filled with glue and painted black. I found that the precise fit of the new bearings highlighted a misalignment in the bearing mounts, so I ran a small round file across the mounts to straighten things up. The wider rear wheels allow fitting of wider and lower race rubber.
To hide the changes, I turned down the old Scalextric rear wheels to fit as inserts in the new aluminium wheels. This was done by putting the Scalextric axle in a drill chuck and running a Dremel against the plastic wheel. Some patience is required, as it’s easy to take off too much or overheat the plastic. While you are at it, the new rear rubber is significantly wider than the originals and might attract some attention. I ground a little off so it is not so conspicuous.
Another way to improve cornering speed is to get the blade of the guide to sit further into the slot. The replacement tyres I used on the rear have a lower profile so I used the same ones on the original front wheels. That left the front tyres clear of the ground, being held up by the