Cobra C2213/18 Motor Propeller Data
Motor Wind Motor Kv No-Load Current Motor Resistance I Max P Max (3S)
18-Turn Delta 1350 RPM/Volt Io = 0.68 Amps @ 8v Rm = 0.068 Ohms 20 Amps 220 W 
 
Outside Diameter Body Length Total Shaft Length Shaft Diameter Motor Weight
27.7 mm,  1.09 in. 28.0 mm,  1.10 in. 42.0 mm,  1.65 in. 3.17 mm,  0.125 in. 61.0 gm,   2.15 oz
 
Prop Prop Input Motor Watts Prop Pitch Thrust  Thrust Thrust Eff.
Manf. Size Voltage Amps Input RPM Speed Grams Ounces Grams/W
APC 8x6-E 7.4 12.64 93.5 7,830 44.5 484 17.07 5.17
APC 8x8-E 7.4 15.94 118.0 7,220 54.7 461 16.26 3.91
APC 9x3.8-SF 7.4 13.02 96.3 7,730 27.8 637 22.47 6.61
APC 9x4.5-E 7.4 11.89 88.0 7,940 33.8 609 21.48 6.92
APC 9x4.7-SF 7.4 13.23 97.9 7,690 34.2 657 23.17 6.71
APC 9x6-E 7.4 13.66 101.1 7,620 43.3 618 21.80 6.11
APC 9x6-SF 7.4 19.87 147.0 6,510 37.0 701 24.73 4.77
APC 9x7.5-E 7.4 18.12 134.1 6,830 48.5 593 20.92 4.42
APC 9x7.5-SF 7.4 21.96 162.5 6,070 43.1 634 22.36 3.90
APC 10x3.8-SF 7.4 18.41 136.2 6,750 24.3 816 28.78 5.99
APC 10x4.7-SF 7.4 19.54 144.6 6,550 29.2 824 29.07 5.70
APC 10x5-E 7.4 15.80 116.9 7,240 34.3 733 25.86 6.27
APC 10x6-E 7.4 15.91 117.7 6,916 39.3 741 26.14 6.29
APC 10x7-E 7.4 17.51 129.6 6,610 43.8 742 26.17 5.73
APC 10x7-SF 7.4 23.80 176.1 5,730 38.0 796 28.08 4.52
APC 11x3.8-SF 7.4 19.78 146.4 6,460 23.2 875 30.86 5.98
APC 11x4.7-SF 7.4 22.59 167.2 5,860 26.1 914 32.24 5.47
APC 11x5.5-E 7.4 18.22 134.8 6,470 33.7 846 29.84 6.27
GWS 8x4x3-DD 7.4 8.59 63.6 8,570 32.5 460 16.23 7.24
GWS 9x5-DD 7.4 11.78 87.2 7,970 37.7 623 21.98 7.15
GWS 9x5x3-DD 7.4 14.42 106.7 7,500 35.5 675 23.81 6.33
GWS 10x6-DD 7.4 15.21 112.6 7,370 41.9 736 25.96 6.54
GWS 10x6x3-DD 7.4 18.65 138.0 6,720 38.2 825 29.10 5.98
GWS 10x8-HD 7.4 21.43 158.6 6,170 35.1 681 24.02 4.29
GWS 11x7-DD 7.4 20.27 150.0 6,350 42.1 885 31.22 5.90
 
Prop Prop Input Motor Watts Prop Pitch Thrust  Thrust Thrust Eff.
Manf. Size Voltage Amps Input RPM Speed Grams Ounces Grams/W
APC 7x4-E 11.1 10.57 117.3 12,330 46.7 620 21.87 5.28
APC 7x4-SF 11.1 10.87 120.7 12,280 46.5 617 21.76 5.11
APC 7x5-E 11.1 13.17 146.2 11,790 55.8 626 22.08 4.28
APC 7x5-SF 11.1 13.36 148.3 11,760 55.7 653 23.03 4.40
APC 7x6-E 11.1 13.88 154.1 11,640 66.1 672 23.70 4.36
APC 7x6-SF 11.1 16.07 178.4 11,230 63.8 619 21.83 3.47
APC 8x4-E 11.1 15.09 167.5 11,410 43.2 829 29.24 4.95
APC 8x6-E 11.1 20.84 231.3 10,230 58.1 895 31.57 3.87
APC 9x4.5-E 11.1 20.00 222.0 10,380 44.2 1082 38.17 4.87
GWS 7x3.5x3-DD 11.1 8.07 89.6 12,900 48.9 520 18.34 5.81
GWS 8x4-DD 11.1 12.00 133.2 12,030 45.6 767 27.05 5.76
GWS 8x4x3-DD 11.1 14.53 161.3 11,530 43.7 840 29.63 5.21
GWS 9x5-DD 11.1 19.48 216.2 10,510 49.8 1096 38.66 5.07
 
Prop Prop Input Motor Watts Prop Pitch Thrust  Thrust Thrust Eff.
Manf. Size Voltage Amps Input RPM Speed Grams Ounces Grams/W
APC 5.5x4.5-E 14.8 9.74 144.2 17,080 72.8 441 15.56 3.06
APC 6x4-E 14.8 10.99 162.7 16,780 63.6 604 21.31 3.71
APC 6x5.5-E 14.8 13.92 206.0 16,080 83.8 579 20.42 2.81
APC 7x4-E 14.8 17.00 251.6 15,370 58.2 1011 35.66 4.02
APC 7x4-SF 14.8 18.14 268.5 15,100 57.2 997 35.17 3.71
APC 7x5-E 14.8 20.71 306.5 14,490 68.6 979 34.53 3.19
APC 7x5-SF 14.8 21.39 316.6 14,340 67.9 993 35.03 3.14
APC 7x6-E 14.8 21.52 318.5 14,320 81.4 1047 36.93 3.29
APC 8x4-E 14.8 23.33 345.3 13,800 52.3 1268 44.73 3.67
                   
Propeller Chart Color Code Explanation
   The prop is to small to get good performance from the motor. (Less than 50% power)
   The prop is sized right to get good power from the motor. (50 to 80% power)
   The prop can be used, but full throttle should be kept to short bursts. (80 to 100% power)
   The prop is too big for the motor and should not be used. (Over 100% power)
PLEASE NOTE: 
The data contained in this prop chart is based on actual measurements taken in a controlled test 
environment.  The test voltages used are based on a properly sized Li-Po battery for the current
draw of the motor being tested.  If you are using a larger than normal capacity battery, or a very
high C-Rated battery, your actual voltages will be higher than those shown in this chart, and this
will result in higer current draw for each prop used.  You should always test your power system
with a watt meter whenever a prop is used to ensure that you are not exceeding the recommended
rating of the motor being used.  The prop recommendations in this chart are based on the motor
receiving adequate cooling throughout its operation.  If your motor is being used inside a cowl, you
must provide adequate cooling to the motor and make sure that the motor is not getting too hot
during operation.