good point on rpm, but they(bigbore pipes) were pretty comfy running at 8800rpm. If I wanted to run higher rpm a couple cuts to them would do it. theres no giant differance between the big bore pipes and the high rpm pipes, measured them. There was a slight change in 2 spots. but easily done. I know the race pipes are hard to find vs the big bore pipes, thats why I referred to them. Possibly ,Rich might make him a set,dont know. Most times your going to make some kind of changes to pipes anyways with dyno tuning if your building a race engine so get the pipes in maximum tune with the engine.
most "drag races" for isr would be 500-660ft long, your gonna have a hard time running with a improved f7 in that distance simply because of the weight break for twins vs triple. Now if your referring to speed running it does help the triple to go longer distance.
Minimum combined weights (sled and rider):
Improved Stock 600 - 700 lbs (645 for 2 cylinder engine)
Improved Stock 700 - 750 lbs (695 for 2 cylinder engine)
Improved Stock 800 & 1000 - 775 (685 for 2 cylinder engine)
Sleds moving to higher displacement classes will not be required to meet the minimum weight for that class