Rotary Racer Performance


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Testing the new GpSpeed controller
Testing the new GpSpeed controller

Rotary Racer 6 Performance

Race Testing

AirTunnel Testing

Gearing

The current gear ratios are 17:57 A spreadsheet showing possible ratios follows: Gearing.xls

Car Computer Logs

Car Details - 2006-11-04

Weight

Cars weight

48.2Kg

Battery Weight

19.4Kg (each)

Drivers Weight

40Kg (average)

Total all up weight

127Kg

Rolling Drag

The rolling drag was calculated by pulling the car at a slow speed using a pair of force guages in parallel. The car had driver but no batteries and the chain and motor where driven. The car was pulled in alternate directions on a tarmac surface and the results averaged. Note the values are inaccurate due to: ground slope, wind, surface roughness.

Weight

88.2Kg

RollingForce

8N

GreenSim simulator

The greensim simulator simulates the RotaryRacer and is configured using the calculated performance values by default. Information is on the page GreenSim.

Battery Testing

This was carried out around 2006-02-09 using the CarComputer to measure the voltage and current and store the results every second.

The load used was RPod's light bulb loads. This consist of two banks of 5 x 12V 50W halogen spot light bulbs. For the 20Amp test one bank was used. For the 10Amp test the two banks were used in series with both banks having 3 bulbs connected.

The Batteries used where the RR1 and RR2 batteries. These were Halfords Calcium HCB096. They have a cold cranking current of 700Amps for 30 seconds and a reserve capacity of 130 Minuies at 25 Amp. They have been raced a few times.

Battery RR1 20Amps 2007-02-09

Battery RR2 20Amps 2007-02-09

Battery RR2 10Amps 2007-02-09

This test shows that Battery RR2 is definitely faulty. It aslo shows that even RR1 did not match the 130 Minutes at 23 Amps.

Battery Testing, Varta

This was carried out around 2007-07-14 using the CarComputer to measure the voltage and current and store the results every second.

The load used was RPod's light bulb loads. This consist of two banks of 5 x 12V 50W halogen spot light bulbs. For the 20Amp test one bank was used.

The Batteries used where the RR5 and RR6 batteries. These were Varta E9 Blue Dynamic. They have a cold cranking current of 640Amps and have a capacity of 70 Amp Hours at the rate. They have done at least three races.

Battery RR5 20Amps 2007-07-14

Battery Testing, Yuasa Elite

This was carried out around 2007-07-13 using the CarComputer to measure the voltage and current and store the results every second.

The load used was RPod's light bulb loads. This consist of two banks of 5 x 12V 50W halogen spot light bulbs. For the 20Amp test one bank was used.

The Batteries used where the RR9 and RR10 batteries. These were Yuasa Elite 100T. They have a cold cranking current of 680Amps and have a capacity of 70 Amp Hours at the 20 hour rate. They are new batteries.

Battery RR9 20Amps 2007-07-13

Battery Recovery Testing, Varta

This was carried out around 2007-07-15 using the CarComputer to measure the voltage and current and store the results every second.

The load used was RPod's light bulb loads. This consist of two banks of 5 x 12V 50W halogen spot light bulbs. For the 20Amp test one bank was used.

The Battery used was the RR6 batteries. These were Varta E9 Blue Dynamic. They have a cold cranking current of 640Amps and have a capacity of 70 Amp Hours at the rate. They have done at least three races.

Battery RR6 20Amps 2007-07-19

Battery RR6 20Amps with recovery 2007-07-15

The battery lasted about 2.6 hours. This is 0.4 hours better than a straight discharge of the RR6 batteries (about 18%).

Motor Speed Controller

Motor speed controller efficiency testing. This was done with two motors connected with a chain. The first motor was powered eithier direct to 12 volts or through the Motor Speed Controller. The second motor was connected to one of Rpod's halogen bulb loads. Voltage and current through both motors was measured. The test shows that the overall efficiency of the motors and drive chain was about 35%. This is probably made up something like: Motor1: 62%, Motor 2: 62%, Chain: 95% although using the motor as a generator is probably less efficient than using it as a motor. The Motor Speed Controller was run a 1.0,0.9 and 0.8 full power and the overal efficiency tested. At full power there was no appreciable loss in the MSC. At 0.9 * full power the efficiency was 97.9% and at 0.8 * full power the efficiency was about 95.75%.

Motor Speed Controller

Type

V In

A In

Power In

V Out

A Out

Power Out

Efficiency

Efficiency MSC

Straight

11.77

17.1

201.27

5.1

13.8

70.38

34.97

S

11.71

16.6

194.39

5.01

13.3

66.63

34.97

MSC 1.0

11.74

17

199.58

5.09

13.7

69.73

34.94

MSC 1.0

11.75

17.3

203.28

5.05

14.1

71.21

35.03

MSC 1.0

11.78

16.8

197.9

5

13.8

69

34.87

MSC 0.9

11.7

14.2

166.14

4.4

12.4

54.56

32.84

97.9

MSC 0.8

11.76

12.1

142.3

3.84

11.4

43.78

30.76

95.74