Kinda weird that the hotbodies doesnt require jetting, yet its one of the freer flowing exhausts out there. I have an FMF carbon/titanium tip slip-on, and it was guaranteed to not need jetting. I need to rejet mine. There is a price to pay for going the easy route. U will gain a little power in some areas and lose power in others. Ive been on here a while and seems at the very least everybody suggests shimming the needles. Seeing as I have the 2 year extended warranty with mine, I will have to let the dealership install my jet kit.
I agree with spooph on this one. I have the HMF which has grown a notorious reputation as the "deep, bass, growly humming" sound you want in lower-mid range RPMs, along with a nice angry SNAP to it once you hit the 8.5k line.
I recommend it highly, it is easy to install, comes with full directions, can be customized drastically, and the people from HMF are GREAT! I have the brushed black elliptical with polished euro tip. Pretty standard, and is the one in the video you see above.
But, I did get a jetkit and have my carbs re-synched along with putting it on. I also went and removed the stock snorkel from the airbox and topped it off with a K&N air filter instead of the crappy foam stock.
When I first installed and road without these modifications, it backfired quite frequently, albeit not a severe, hugely loud backfire, more of a bunch of low firecracker thuds as I backed off the throttle or downshifted at too high an RPM. It also was more bogged down then it was after the above mentioned rejetting and mods, undoubtedly.
Don't ruin your valve timing for no reason- spend the cash or time (or both ) and get it properly rejetted or at the least have the needles shimmed.
If you want I can post a video of my exhaust with a great GoPro HD camera (great audio and wide lens capture) in revs from 2-6k / 3-9k / and than some from 2-12.5k, plus an additional drive-by so you can really make an educated decision. Just let me know via PM or this thread.
I also have a bunch of YouTube videos up with some silly video logs of random rides,