header exhaust

Does header exhuast really hurt the power on my KZ1100, and if so, why?

im sure there are many headers that work worse than stock exhuast

lol ok that doesn't help.

weve had discussions before about dyno results of differant headers robbing power,most ads are hyped up to sell parts

most header and pipe setups force you to trade torque for hp and the japs did a decent job of balancing both really just be sure to do your homework and buy the pipes that fit your riding style

I love the way my headers alone make my bike look...I want to muffle the sound down a little bit, and wrap them up....I dont have the money to get an exhaust system...

what kind of header are you running?

stock....I cut them from the collector..i have a few pics here on the forum...and you can see how they look...

Darkangel wrote:

stock....I cut them from the collector..

So, you are running a straight pipe. Yes, that will screw up the power your motor makes.


Darkangel wrote:

I want to muffle the sound down a little bit

Yeah, straight pipes tend to make your ears hurt.

why does it hurt it..?

Darkangel wrote:

why does it hurt it..?

Bike engines make a LOT of power from very small displacement. To do that, they are tuned up very precisely for airflow and fuel mixture. The intake side (carbs and airbox) along with the exhaust system have airflow characteristics that the carburetors are designed to match. That's why carburetor needles have a specific size, length and taper. Changing the exhaust changes the airflow rate through the engine. Going to a straight pipe greatly reduces backpressure making more air flow through the engine, which means that it will be running too lean with the carbs which were designed to work with the stock exhaust.

Motorcycle exhaust systems are engineered for the specific engines to which they attach. On stock bikes, the factory engineers match the flow characteristics of the exhaust system to that of the engine and carbs to strike a balance between power across the entire powerband and sound attenuation. On race bikes sound attenuation isn’t really an issue so the exhaust is tuned to work at the powerband range most important to the type of racing involved. For example, they may sacrifice power at low RPM to maximize power in the meat of the powerband. Take a look at pictures of any superbikes and you’ll see they don’t simply cut off the pipes. They all have small but highly engineered “mufflers” (by Yoshimura, Muzzys, or some other engineering firm) who purpose is to maximize power rather than minimize sound. Aside from the power loss and excessive noise, open headers can lead to valve failures. Ed