[Duker]

Has anyone installed a HMF sport series slip on with out doing a fuel/air change? Other than a big improvement in the sound, what would you expect? Would it lean out the engine to the point where performance or damage could occur?

 

[bkabner]

Hey,

I have installed the Bill Ballance Pro Series HMF...full exhaust, and programmer. I just installed the full exhaust and rode it for one days ride....I could tell a little bit of difference, but not all that much. This is just my opinion based on experience, a slip-on is worthless without the head pipe to occompany it. All of these companies claim an 11hp gain with full exhuast system, I would like to see that proof on a dyno. I'm feeling okay with the idea of 5-7hp gains with full exhaust. I know that the stock exhaust on the 700xx restricts a lot of air flow...and a bolt on exhaust system is one of the "big 3" upgrades done by most owners. Thats enough of my two cents, I'd seriously reccomend the full exhaust and the hmf programmer...gotta get that beast some more fuel! lol

 

[THREESVTS]

If you do a slip on you should also do a programmer. They run very lean stock and a pipe would bring it dangerously close to the ragged edge of lean.

bkabner I have to disagree with you. A slip on is the majority of gain you get from an exhaust. A head pipe does make a difference, but not much that you would notice and it's usually in the 1 hp range. The stock head pipe on the 700xx is more than adequate for what we ask of the engine. Now if you do an over bore and cam then yes you need a better head pipe. I installed a Yoshimura RS3 slip on on my xx and the difference was like night and day. But I am using a PCIII and not an HMF programmer. I'll be going to the dyno in a few weeks to see the after "the big 3" hp and tq.