Timing on a modern sensored RC Motor system can be confusing for beginners to RC Racing. Knowing the basics will help you get the most out of your RC car.
How altering motor timing affects performance
Altering timing has a similar effect to changing the gearing. Advancing (increasing) a motors timing will result in a higher maximum motor RPM but will reduce Torque. Reducing timing does the opposite – more Torque, lower maximum motor RPM.
RPM (Revolutions Per Minute): higher RPM = higher top speed
Torque: more pulling power = quicker acceleration
How much torque or RPM you need will depend on the car and the track or area you are racing on. Racing on a smooth surface with less rolling resistance means you can get more top end out of your car. Racing off-road on grass or difficult terrain would be better suited to a higher torque setup.
So why bother adjusting Timing if you can simply change the gearing?
There are a number of good reasons to play around with the motor timing. Read on to learn about the various ways it can be changed and a simple explanation.
There are 3 ways to adjust timing on an RC Motor:
- Fixed timing on the motor can (Mechanically)
- BOOST – Electronically on the ESC linked to RPM
- TURBO – Electronically on the ESC linked to full throttle position
Adjusting timing on the RC Motor Can
Timing that you set on the motor can is fixed if no Boost or Turbo is used. Motors are often set to 30 degrees from the factory, and this is a good all round starting point.
How to adjust on the can
Adjusting the timing on the can is usually done by undoing a screw and rotating the back of the motor. Markings will show the current timing setting (usually marked in degrees, but not always) and you can increase or reduce the timing by twisting the rear of the motor. Don’t forget to re-tighten when set.
Some motors don’t allow timing adjustment at all, and some provide an insert that you can swap around to give you two adjustment options. The variable ones are the best as they allow finer adjustments.
The effect of changing the motor timing on the can
More timing on the can will increase the RPM but reduce torque and efficiency (reducing run times). The motor will also run hotter, the more timing you add. It has a similar effect to changing the gearing to a higher gear – so be careful not to go too high if you are already geared high.
Boost and Turbo timing added on the ESC
If your ESC (Electronic Speed Controller) supports it, controlling timing electronically with Boost and Turbo can give you a lot more control over how and when the power comes in.
This can be very useful on different tracks, such as one consisting of a very long straight where you need maximum top end, but then need the car to be easy to drive around the infield and technical sections of the track.
Any Boost or Turbo timing added on the ESC will be in addition to the timing that is mechanically set on the motor. For example, If your motor has the timing mechanically set at 30 degrees, and you have dynamically added 10 boost and 5 turbo, your maximum timing will be 45 degrees when at full throttle and the required Boost RPM has been reached.
Boost and Turbo can be used independently, or together for maximum effect. Some racers only use Boost, and some only use Turbo, so it is all down to personal preference. The size and complexity of the track you are racing at should help you decide what to use.
Boost timing takes effect at a predefined RPM range that you program on the ESC.
For example, starting with 30 timing on the motor, if you then specified on the ESC an additional 10 degrees of Boost at the following RPM ranges:
Boost Start @ 8,000RPM
Boost End @ 20,000RPM
Up until 8,000RPM, you’d have the default 30 degrees of timing. Once you go over 8,000RPM, timing would be incrementally increased by a maximum of 10 – but only when you have hit the 20,000RPM that you set.
Anything above 20,000RPM, and your total timing would always be 40 degrees, not 30.
When setting RPM ranges, always check the ESC’s log feature to see what your maximum RPM is on the track. If you set a value above your maximum RPM, then the full amount of extra timing would never get added, because the car is not reaching the RPM required.
Setting a wide range, such as 4,000-30,000 RPM would create a more gradual increase in timing, so should in theory make the car smoother.
Setting a narrow range, such as 12,000-16,000 RPM would mean the change is more sudden, so may feel more aggressive.
Experiment with different RPM range settings and see what feels better.
Turbo timing is quite simple – it is activated at full throttle, and the moment you come off full throttle it is deactivated.
So if your timing on the motor is 30, and turbo is set to 15, you will end up with 45 degrees of timing when at full throttle, regardless of the speed or RPM of the car.
You can set a delay for when the turbo timing kicks in, which helps when you only want it to activate on the long straights, etc.
Using Boost and Turbo Together
Using Boost and Turbo together simply adds all the timing together. So using the values from the above examples, you’d end up with: 30 + 10 + 15 = 45. Use with caution! Be sure to keep an eye on motor temperature.
Experimenting with different settings and configurations is the best way to find out what works for your situation.
Remember to check your ESC and motor manual for some recommended RPM ranges and helpful information.