What is the fine-grained topic of the following text: All of this work comfortably doubles the horsepower of the standard bike and there’s a big lift in torque all the way from 48 ft/lb at 3200rpm through to a peak of 55 ft/lb at 6200rpm, tailing off only a little to 50 ft/lb at 8000 rpm. Only return the topic.
Improving motorcycle horsepower and torque