i'm a firm believer in that getting that pipe out from crossing in front of the motor has to allow it to run cooler as the right bends do, and have always wanted a toomey myself, they just sound a different kinda nasty than anything else i've heard, but have f7's on both my and sons bikes, got mine in great shape dirt cheap on here, and it made a huge difference in the power of the bike, comes on strong in the mids and pulls forever,
on my boys bike it comes on earlier with less mods and stock carb, and also pulls forever, but his i have no silencer packing and it sounds like a 250 dirtbike, obnoxiously nasty
but the toomeys are great pipes also, but i prefer the pipe not blowing hot air on the motor