actually, average thrust doesnt determine model from high power. its total impulse. anything classified as a G is absolutely positively legal,(for lack of a better term) to fly, as long as the TOTAL impulse does not exceed 160Ns. which would be a 100% G motor. so no matter what G motor it is, its got 160Ns or less, and therefore is safe to fly with no cert. and as you progress up the line of the alphabet, the total impulse doubles. so if a full G is 160Ns, then the next highest is an H, so it would be 320Ns TOTAL impulse for a FULL H motor. that doesnt mean it can't be less, but it means it can't be more than 320, and it can't be less than 161 or else its not an H.
AVERAGE impulse is a different thing. if i had a G160(i dont even think anyone makes one...but just as an example) then i would KNOW that that motor will burn for 1 second exactly. because a G motor has 160Ns of total impulse. however, if i had a G320, then i would know that THAT motor would only burn for HALF a second, because its got twice the impulse and in order for it to be a G, it would have to burn for less than a second. PM me if you still dont understand, its not the easiest concept, but it gets more understandable the more you work with it.
