Re: opinions on open pipes

Posted by LukeM on Apr 20, 2010; 12:19am
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/opinions-on-open-pipes-tp722704p731113.html

Based on the limited reading I've done so far (Clymer and Haynes manuals), if the exhaust is less restrictive, all other things being equal, the motor will run lean.  With the decreased back pressure, when the motor comes around on the intake stroke, some of that intake charge will go out the exhaust port, meaning less fuel and air in the cylinder for the power stroke.  That's why you jet up one or two steps when running open pipes.

Just my opinion, and what I've gleaned from the research I've done so far.  I do like the sound of the factory pipes on my bike, and find my son's CB550F with straight pipes a bit obnoxious and loud.  However, I can chalk that up to him being young and riding his first bike.  He also believes loud pipes save lives, which has some merit, but is more of a philosophical discussion.

My $0.02 worth.
Luke M