16 things you need to know before racing rc cars.

There is a strong likely hood that you have been interested in remote control cars since you were a kid. You most likely own or have owned a remote control car at some point in your life. Racing remote control cars is very exciting, demanding and rewarding. When I started racing, I jumped in at the deep end and felt a little out of my comfort zone. Over the years I have picked up the lingo and learned about the different aspects.

In my opinion racing RC cars is the best way to have fun with remote control cars. It’s a cheap form of motor racing that poses no risk to injury like most other forms of racing. For those of you thinking about getting into RC racing I have put together this list of 16 things I think all enthusiasts should know before you start.

1: Pick a popular local race class.

There are so many different classes of remote control cars to choose from, and sizes within each class. It can get a little daunting to begin with. For you to have the most enjoyment I would suggest you look for tracks local to you. Once you find a few tracks locally you will get a good idea for which is popular near you. Pop down to your local track and have a look at what the racers are using.

Its wise to go with a popular car used at your local track. You stand more chance of spare parts and support being available. It’s no fun purchasing a car and the nearest track is in the next state. Or you have to wait for weeks on end for replacement parts. Some tracks have shops on site.

The most popular classes worldwide are:

  • 1/10th off road 2 wheel drive & 4 wheel dive electric.
  • 1/10th on road nitro and electric.
  • 1/8th off road nitro and electric.

2: Nitro cars – fuel percentages.

Nitro cars are fun! – the sound of the engine and the smoke out the exhaust. Gives them a more authentic feel than electric RC cars. When you start looking at the fuel options, you will notice different brands and percentages. In racing you tend to use higher percentage nitro fuels 20% – 25%.

In general 1/10th scale RC cars have smaller engines than 1/8th scale cars. With that said you also have different size engines for each class. The manufacturer often states the recommended % fuel in the instruction manual which came with your engine.

If you increase the percentage then your engine will run leaner. You will need to re-tune your engine to compensate for this. The opposite effect happens when you decrease the percentage. Your engine will run richer and you will need to re-tune to compensate. Your engine can also need re-tuning when you switch brands. It’s wise to stick with the same brand and percentage. Some manufacturers will state the brand of fuel they recommend. Don’t worry too much if that brand is not available locally. The important factor is the percentage rating.

 

3: Nitro Cars – engine basics.

  • Glow plugs – 1/8th scale nitro engines most commonly use a “turbo glow plug” in race spec engines. These are shaped differently to a standard glow plug, the thread is also different.
  • Exhaust pipe – Exhausts are sold separately in most cases (combo deals include exhausts). The reason for this is exhausts are used as a tuning option. Your engine can produce more low end, mid range or high end torque depending on the exhaust you use. In the beginning you won’t notice much of a difference.
  • Tuning – Nitro engines have 2 main tuning points. When you make tuning adjustments make sure you make very small adjustments. We are talking 1/8th of a turn. Turning the screws clockwise will make the air-fuel mixture leaner. Turning the screws anti-clockwise will make the mixture richer. The high speed needle is to adjust how lean or rich the engine is at the top end of the rev range. The low speed needle is to adjust lean or rich settings at the low end of the rev range.
  • Venturi – a venturi is an air restrictor that sits inside your carburetor. You attach your air filter over the venturi. You can adjust the performance of your engine with different size venturis.
  • Engine starting procedure – Once you have fuel in the tank and a glow plug igniter attached your ready to start your engine. Most nitro engines designed for racing do not come with a pull starter. The only way to start a race spec engine is with a starter box. This is essentially a box with a rubber wheel. When you push your car down on the starter box the rubber wheel makes contact with your flywheel and turns your engine over. I wrote a more detailed article on how to pick the best starter box here.

4: Electric cars – Lipo batteries.

Lipo (lithium polymer) is the latest in battery technology. Before Lipo came along the most commonly used batteries where Nimh (Nickel-metal hydride) and Nicad (Nickel-cadmium battery).

Lipo batteries provide a longer run time (higher mah ratings) and more initial punch (higher discharge “C” ratings). More speed for longer is very good for the racing industry. The main downside to Lipo batteries is you cannot let them fully drain. You need to keep them above 3.0v per cell. With the older technology you could drain the battery till it was flat and then charge it all the way up.

Make sure your ESC (electronic speed controller) is compatible with lipo batteries. This will take care of the 3.0v per cell cut off. When it comes to charging lipo batteries you will need a lipo charger. This will constantly monitor the voltages as your battery is charging and automatically cut off at the correct voltage. Usually around but no higher than 4.2v per cell.

Racing restrictions – 1/10th electric cars are usually restricted to 2 cell batteries (2s). 1/8th electric cars are restricted to 4 cell batteries (4s).

5: Electric cars – motor & esc basics.

You can get brushed and brushless electric motors. Brushless is the more common electric motor used on race tracks. You can still get the odd class which will run brushed motors.

  • Sensorless brushless motors. These motors will work with almost any type of brushless ESC (electronic speed controller). You connect the motor to the ESC using 3 wires normally in 3 different colors or labeled as A,B & C. You can change the direction of the motor by switching any 2 of the 3 wires around.
  • Sensored brushless motors. Very similar to a sensorless brushless motors with 3 wires. The main difference is you have a sensor cable which tells the ESC exactly where the rotor position is. Sensored motors are smoother in acceleration and initial starting. Your ESC will need to be compatible with sensored brushless motors. These motors will also work in sensorless mode if you do not use the cable.
  • Brushed electric motors. Considered old school these days. You connect the motor to your ESC using 2 wires normally black and red. Brushless ESC’s are not compatible with brushed motors. You need to maintain the brushes on an electric motor, without the brushes the motor will not rotate properly.

6: RC Car setup options.

Racing spec rc cars have so many tuning options available. If you think of F1 and all the tuning options they have shocks, differentials & tires. You won’t be far off the options available on an RC car.

Here is a list of some of the tuning options that spring to mind:

  • Chassis tuning – differentials, camber, camber rise, droop, ride height, anti roll bars, ackermann, weight balance & steering symmetry.
  • Suspension – shock shafts, bladders, shock oil & spring rate.
  • ESC & Motor – drag break, punch rate, breaking force & initial force. More details on ESC options here.
  • Nitro Engines – exhausts, fuel, venturi & air filters.
  • Wheels & Tires – different compounds, inserts & tread pattern.

7: Track day format.

There are some differences to how a track day will work depending on the class you race. 1/10th scale tends to be indoor, each qualifying round lasts about 5 minutes. Finals are not much longer most tracks still run on the old rules set with weaker batteries (nimh and nicad). 1/8th scale is mostly outdoors each qualifying round will last approx 6 minutes with 2 minutes warm-up. The finals can last up to 1 hour with nitro and around 15-20 minutes with electric cars.

Both indoor and outdoor events will start the day with a drivers briefing. Pay attention to this as the race director will explain the rules and layout of the day.

Here is an article I wrote on what to expect at a track day.

8: Marshalling.

 

Unfortunately is not all about racing. At some point during a race event you will need to marshal on the track while other drivers race. Unless you have very helpful friends you can bring with you. You will normally marshal the round after or before yours. The marshal point you stand at will be the same as your race number.

You will find out your race number during the drivers briefing. Most tracks don’t have a budget to pay for marshals and that is why you marshal other racers. A marshal is your best friend when you crash on the track. They are the only people allowed to be out on the track during a race.

9: Track surfaces.

Depending on what is local to you. You may not have a choice on the track surface. If you are willing to travel or lucky enough to live in an area with different tracks. There are different surfaces to race your RC car(s) on. The common theme for Europe indoor tracks is carpet. For outdoor tracks they are usually astro turf. In America the indoor tracks are commonly carpet, clay or dirt and outdoor is mostly clay or dirt.

  • Astroturf – great all year round surface easy to maintain 1/10th & 1/8th scale.
  • Carpet – indoor tracks only and used for 1/10th & smaller scales.
  • Dirt – very different to astro turf. requires more maintenance very difficult to race on when it’s raining.
  • Clay – similar to dirt mostly found on indoor tracks.
  • Tarmac/concrete – more common for on road cars although some dirt and astro tracks can feature tarmac/concrete sections.

10: Transponders.

A transponder is a small electronic device which carries a unique ID. You connect this to your cars receiver. As you go over the loop (pick up device under the finish line) it sends the unique ID to the decoder. The computer can then accurately record your lap time and position on the track. The same type of system is used at go kart tracks.

It’s best to mount your transponder so the signal is aimed down. I have attached my transponder in all areas and not usually had a problem. There is no evidence to say the front of the car is the best area. You may get 0.0001 of a second difference however the decoders don’t record at that level.

If you do not own your own transponder, speak with the race director and ask if they have hand outs. Some tracks lend out transponders. This is not very common as they are expensive devices. If you do not have a transponder in your car you will not know how you performed. Some race directors will not let you race without one.

11: Radio equipment.

In simple terms this consists of a transmitter, receiver, servos and transponder. 2.4ghz is the most used frequency, it was once 27 mhz and 40 mhz. With 2.4 ghz you bind the transmitter and receiver together. Just like when you sync xbox or Wii controllers. You don’t need to use a crystal. This frequency offers better range and signal strength.

There are 2 main types of transmitters for racing RC cars. Wheel transmitters use a finger trigger to operate forward and brake. They use a wheel to operate the steering. Stick transmitters have been around longer and as the name implies use sticks. You operate forward and reverse with the left stick and left/right directions with the left stick.

Wheel Transmitter

Sticks Transmitter

Receivers come in all sizes be sure to check the rx box dimensions. Some are waterproof, if yours is not you can put it inside a small balloon. You plug everything into your receiver, ESC, servos and transponder.

Servos are used for steering and in nitro cars to operate the throttle and breaks. They come in different speed & torque ratings. HV (high voltage) servos operate at 7.4v this is the voltage of a 2 cell (2s) lipo battery. The higher voltage provides quicker response times and more torque. I like to use the same servo for steering and throttle/breaks here is my favorite servo and why.

12: Body shells.

RC body shells are usually made out of Lexan and on race spec rc kits come clear. You can paint them yourself or have them professional painted to have any design you want. Be mindful when you start out that mistakes will happen and body shells take the brunt of most crashes.

13: Camping.

If your a keen camper than you will love this. Some people who travel long distances will camp the night before race day. Larger racing events are held over the weekend or several days. Camping and racing go hand in hand. Most RC tracks will let you camp on site or may have permission of a nearby field.

If you are not keen on camping and you want to attend tracks further away or events over several days. Check hotels and B&B’s local to the track. Large events like the Neo race will have recommendations on hotels and places to stay – If your lucky you may get a discount at the place you stay (no harm in asking).

14: Tools.

You will inevitably create a growing list of RC tools. You can’t really maintain your car or change a setup/tuning option without tools. When you buy your first race kit it will come as a box of bits. You will need to assemble every part by hand. Unless you decide to pay the shop or a someone to build it for you. I wrote a list of the most common tools I use.

15: National and worldwide championships.

Once you get involved in the racing scene. you soon quickly realize that it is bigger than you think. Speak to any of your non RC friends about racing rc cars. Do they look at you with a strange glare?. RC racing like any other form of motor-sport has club, regional, national and world tournaments.

There are paid professionals in this industry just like Nascar. Not as many mind you and they won’t be paid on the same scale as a Nascar professional. As you get more involved you start to notice more, there is a big following!

There are requirements to enter the larger races. Some you must qualify highly in order to be considered entry. Club level is always a good place to start learning and developing your skills. It’s not uncommon to see a high profile racer attending a club race. This is one of the few sports where you could find yourself racing against the best or having a coffee with them at lunch time.

16: Spare parts.

Last but not least. It’s no fun when you break something especially on a product you are invested in. The beauty with hobby grade RC cars is they are made up of vast amount of parts. 99.9% of the time when something breaks you can just order the replacement part and you will be back on track.

Crashes will happen, parts break or wear down over time. This is why its important to pick a popular brand which is raced locally. Not only will you have parts availability, but there will be people who can tell you the most common parts which break. You can build a backup of parts and have them ready for when the inevitable happens.

 

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