Hi All, As always...in advance thank you for all the shared knowledge. I'm trying to get a bit more out of my 400s. Riding is about 60% off-road (desert, gravel, BLM roads, power-lines...I ride slow, 35-55 mph) and 40% street (around town, not much highway...again tend to be slow). I've read a lot in Eddie's area about slip-on exhausts vs. full systems and it seems that just adding a slip-on (to an "S" model) doesn't really make much (any) difference because the header is still the restriction. But...I think my question is...if I had an "E" header (which I've read is larger than the "S") then would adding a slip-on be a logical move? Or, is a full-system still going to be the 'best' because the header is even larger and the muffler is 'tuned' for that specific header? Cost/budget is a factor here...seems a slip-on/"E" header could be found for less money than a full-system. But if there's still nothing to gain from adding a slip-on to an "E" header pipe then I'll just save my pennies for a full system. I'm also wondering if I just geared the bike a little differently I would accomplish what I'm after (but that's a different topic I've also been reading up on). Probably to a certain extent but it still seems like the motor could do more work if it was opened up more with a free-flowing exhaust.