Rotary Racer - Car Performance
Merryfield 2014-07-19
Results
Weather ended up by being good, almost no wind, warm and with just a slight shower or two, much better than the possible thunderstoms predicted. Practice went very well and the new drivers after their spins went fine although we did get a puncture in one of the new tyres fitted near the end of practice. First F24 race was very good and we managed to win. The F24+ was exceptional. We raced neck and neck with Jet the entire race with laps within a second of each other right up to the flag. We were pushing the batteries to do this, and I think Jet was slightly undergeared, but it led to an excellent spectical :). We were just behind by 0.5 secs at the end ! Tom and Dave drove very well with the amount of concentration they had to put in. The second F24 race was again excellent and we managed to win with a good margin.
Car Computer Log
This shows the main items measured by the Rotary Racers car computer. They are:
Item | Description |
---|---|
Throttle | The position of the twist grip throttle from 0 to 100% |
MotorCtl | The motor power output setting. The Car computer sets the motor power based on the drivers throttle position, the speed of the car and the current being used. There is a software algorithm to implement this "drive by wire" system. The Car computer drives the PWM (Pulse Width Modulation) Motor Speed controller with a duty cycle proportional to this value. 0 - 100% |
Speed | The speed of the car in Km/H calculated from the magnetic read switch pulse generator by the Car Computer. |
Voltage | The batteries voltage under load. |
Current | The current being taken from the batteries. |
Charge0 | The charge left in the battery pack 0. This is calculated by the car computer using an algorithm that has been honed to match the battery discharge curves for the Yuasa batteries. It currently bases its results on the current being used from the battery. |
Charge1 | The charge left in the battery pack 1. This is calculated by the car computer using an algorithm that has been honed to match the battery discharge curves for the Yuasa batteries. It currently bases its results on the current being used from the battery. |
Charge2 | The charge left in the battery pack 2. This is calculated by the car computer using an algorithm that has been honed to match the battery discharge curves for the Yuasa batteries. It currently bases its results on the current being used from the battery. |
BatPack | The battery pack in use (0, 1 or 2), the turbo button (4) and the Pitstop warning (8) . We generally change the battery pack with each driver change. |
Temp | The Temperature of the motors casing in degrees C. |
GPS | GPS position, speed and time together with lap position information |
Misc | Other items describing the operation of the control system |
The graphs show the overall data, the actual ASCII data log files are also available, from the links below, for detailed analysis.
F24+

F24 Race 1
F24 Race 2
Practice Laps Data
Notes
- We used an 16:48 gear ratio in the F24 and a 20:48 in the F24+
- F24+ driver was: Tom.
- F24-1 drivers were: Jacob, Tristan, Louise.
- F24-2 drivers wereL Louise, Joe, Jacob
- F24-1 Batteries were: RR9/RR10
- F24+ Batteries were: RR13/RR14
- F24-2 Batteries were: RR11/RR12