hi i beed to know the difrent bitwin :
hmf sport series (colors) to hmf qs1 ....

 

http://www.hmfengineering.com/atvcatalog.htm

The link above says it all, they give a very good desription of each.

but in a nut shell, the sport is an open core straight thru high flow muffler, and the qs is an internally baffled muffler that is much quieter. naturally the method used to create the quiet is not going to flow as much as the sport, but supposedly does flow more than a stock pipe.

 

ok , so what you telling me its that the chiper is better?
what is better ??? sport or qs1 ??