[QUOTE=LogicalRetard;3371215]Why is that? Just because more rpms = more opportunity to burn? Just wondering dood.
[QUOTE]

no problem, nitrous is a commonly misunderstood power adder.

the initial hit, and torque spike attibuted to it, puts a lot of unwanted stress on the rotating assembly. its why people say to retard your timing, because nitrous burns hotter and quicker, thus the piston will have alot more load on it before it actually reaches TDC. you can spray a 25shot at 3000rpm, and see a 60rwtq increase, wherease that same shot at say 9000rpm, would only net you a 20rwtq increase. basically, the constant to the equation is the flow of nitrous(given bottle pressure stays the same) ...its all dicated by the solenoid and jetting.

basically you have an engine consuming ~61 cubic inches of air per rotation, for ease of this, we'll just say .035cfm per roation. at 3000rpm(x .035cfm) the ZX10 is pulling in 105cfm, while the nitrous is encompassing 45 cubic feet of that. now at 9000rpm the motor is taking in 315cfm, but still only 45cfm of that is nitrous.