ATVX4
04-22-2006, 09:50 PM
I have an 04 450R with a sparks aggressive drop in cam and hrc end cap. Jetting is at 185 w/hrc lid. I was wondering if a HMF slip on would be a noticable difference. I did a search and could not get a solid answer. I may be putting in a sparks 12:1 piston in also. I hear the stock head pipe is a decent piece, and am concerned about losing low end. Thats why I'm thinking about just the slip on. Also, a full system bumps me up a class in the dirt drag series I run. Thanks.