Motorcycle Repair: 1997 Harley Sportster Exhaust System., harley sportster exhaust, crossover pipe

Question
I have noticed that some Sportsters have an exhaust equalizer or crossover pipe and some do not. Can you please tell me what is the purpose or advantage of the equalizer pipe between the exhaust pipes?

Thanks,
Terry

Answer
The purpose of the crossover pipe is to increase horsepower by using the exhaust pulse of each cylinder to help the exhaust flow of the other cylinder.  Faster exhaust flow means more horsepower.  Problem is lots of people hate the look of the crossover (especially on Sportsters because it covers the cylinders and looks goofy) so they change exhaust to eliminate it.  Harley realized this and incorporated the crossover into the mounting bracket on the twin-cams.  Check out the newest aftermarket exhausts like Vance & Hines Big Shots.  They also have a hidden crossover and claim 20% increase in hp with the addition of this to their existing line.  So if you are going to eliminate it, at least go with a less restrictive exhaust to boost hp and couple it with a hi-flow air filter (and fuel processor on injected models).