He is using a giant pinion gear, so the gear ratio on the car is maybe a 1:3 ratio, instead of your 5.825:1 ratio with stock gearing. Since the servo is already geared down, there is no need for the extra reduction from the gearbox, therefore using a giant pinion gear will give you more speed, but less (but still a lot) of torque. Any more questions feel free to ask =P
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