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Message: [QUOTE="Oldman125, post: 1148462, member: 70686"] Drag race engines use the power band as much as motocross bikes. Well, bikes race from obstacle to abstacle so its a similar circumstance. The drag engine is launched at near peak torque off a trans brake and a loose converter to get it rolling and then kept around peak HP by way of a built automatic or a 5/6 speed manual trans. The plan is to shift just after HP tops out and use the gear spread to allow the RPM to only drop a few below peak HP. The tuner then specs gear ratio and tire diameter to match ETs and length of track so that RPMs top out just over peak at the lights. Power band can be determined by the inlet port size, piston speed (determined by rod length and stroke) cam duration and lift plus bore and stroke and exhaust pipe diameter and length. Simply changing carb size and/or cam profile can change where the power is or where peak efficiency occurs. Most commonly peak fuel efficiency is where peak VE is and tuning the engine combo to the RPM and speed you wish to operate at will net the best fuel milage. (as if we care about that!) The difference btw drag and MX would be that MX is more demanding by nature such as a road race engine would require. Longer spread (different cam and intake specs) and fatter/longer torque curve necessary. Not really a tech post, but my thoughts in relation to your topic. I just find all of this interesting. [/QUOTE]