Using cars with ARC Pro

There are a lot of wonderful slot cars available from many different manufacturers. Pretty much all can be converted to run digitally with ARC Pro or can be used without a digital chip (decoder) in analogue mode. There is one important proviso - that the guide blade must be black in order to trigger the sensors in the powerbase and count laps.

My opinion is that modern Scalextric cars are the best suited for use with ARC Pro - they are easy to convert to digital, they are robust and they are quick, but not too quick. Digital racing is so much more than driving fast, so high-performance slot cars can actually hinder the arts of overtaking and race strategy - and can lead to a very expensive crash-fest.

If you have a good-sized home track - or can set up a big temporary layout - then running slightly faster cars can make an exhilarating change. At our Scalextric digital club, we run mostly standard Scalextric cars with magnets removed, but we do have one race for the Group C cars.

Group C was a golden era of sports car racing in the 1980s and early 90s. Porsche, Lancia, Jaguar, Toyota, Nissan and Sauber were all front-runners and their Group C cars are all available as slot car models from Italian company The slot cars look fantastic, but are also designed for awesome performance. The cars are lightweight, have a flat chassis with an independent motor pod, plus quality components such as aluminium rear wheels and a powerful 23,000 rpm motor.

The SP15B Chip

Most of the Group C cars are designed to take the SP15B digital chip for Scalextric digital - or come with the chip already fitted.

This is my Porsche 956LH fitted with a SP15B chip...

The front of the chip fits tightly around the front body post and the gold-coloured lane changer LED aligns perfectly with the hole in the chassis. I fix the rear of the chip to the chassis with a little Blu-Tak. I also fit a piece of clear polycarbonate sheet to cover the holes in the chassis to protect the chip from dirt, debris and the risk of a short-circuit. The only soldering is to attach the legs of the ferrite filter to the motor terminals. It is important to insulate the motor can from the ferrite filter and also the bottom of the motor from the track rails - I use Scotch Magic tape for both top and bottom.

The ease of converting the cars to digital and their standard black guides make the Group C cars ideal for ARC Pro racing. On a big track, their standard 23,000 rpm MX16 motors are not excessively quick. We remove the traction magnet from the cars and replace it with a SP23 Tungsten weight. This means the cars can't be driven as fast and are actually much more enjoyable to race - the cars are designed for 'non-mag' racing. If you want to reduce the speed even more, it is possible to replace the standard motor with the MX15 21,000 rpm motor or a standard Scalextric (approx 18,000 rpm) motor. A simple alternative is - of course - to adjust the Max Power setting in the ARC app. I find the Profile A or Profile B Throttle Curves are best for running the cars without magnets.

Race Formats

There are plenty of options for race formats. Group C cars raced at Le Mans, in the World Endurance Championship, American IMSA series, the Germany DRM Supercup, the All-Japan Sports Prototype Championship and many more national and regional series. Often these featured a variety of both timed and lap races, allowing us to use either the Endurance or Grand Prix race modes in ARC Pro. For this example, we'll choose a one-hour (60 minute) endurance race using the Custom option in the Time Limit menu...

I've set up the cars as Team 1, Team 2 etc - as we'll be using a pairs format, with each driver racing for half an hour. I haven't picked any pitstop features - fuel, tyre wear, weather or incidents - as the faster cars will require full attention. However, there will be a mandatory one-minute pit stop at half distance. A pit stop window will open after 25 minutes and close at 35 minutes. Within this window, each team will need to stop their car in the pits, remove the car from the pit lane and may clean the tyres (with masking tape), the braids and carry out any other maintenance. The length of the pit stop will be timed with a kitchen timer or a timer on a phone. At the end of the minute, the car is replaced in the pit lane and the second driver starts their racing stint. The timing of the pit window will be the responsibility of the race director - who can be one of the drivers.

I have enabled the Yellow Flag feature, just in case the cars need slowing to remove debris from the track or to repair barriers. The team mates who are not driving will marshal any cars that deslot and return them to the track when safe to do so. Although this is a format that is a little different from our normal ARC Pro races, it works well. With the high performance cars, it makes sense to concentrate on the driving and the racing rather than simulations and pit stops. It is an option for longer endurance races with any type of car.