• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

Quick Muffler question

  • Thread starter Thread starter Anonymous
  • Start date Start date
A

Anonymous

Guest
On a bike with 2 mufflers... is it a problem if on of them is factory and the other is aftermarket? (besides looking funny.....) Will it cause backpressure problems? Or cause the engine to run poorly?
 
It may make it sound funny. Why not change the other one to match
 
It might make it run very funny. Especially if the premuffler has been removed to accomodate the aftermarket. Unless they are both creating the same backpressure, the cylinders won't be running evenly.
 
Can it cause damage to the engine?

Everything before the muffler looks the same... you would assume they would have replaced it with a muffler of the same specs....
 
wizard said:
It might make it run very funny. Especially if the premuffler has been removed to accomodate the aftermarket. Unless they are both creating the same backpressure, the cylinders won't be running evenly.

Excellent point. It is easy to create large differences by changing only one muffler, and that can upset your fuel usage, power output, or damage your engine. Both mufflers should have exactly the same characteristics. If you are not certain of the new one, buy two and be sure.
 
With a stock header all the pipes join into 1, then back out to 2, so a 4 into 1 into 2 setup. Because of this, wouldn't the back pressure equalize?
 
Assuming that the mufflers don't have identical restriction, the backpressure to the exhaust ports will fluctuate, even with the 4 into 1 into 2 setup that you describe. The left muffler will exert more back pressure than the right muffler, forcing more of the fluid (exhaust gases) to flow to the right muffler until it can't handle the volume. Now the right muffler will be exerting more back pressure, forcing the volume to the left side. Since the assumption is made that the mufflers have unequal restriction, this will not take the same amount of time. This should produce a "thrumming" sound in the exhaust system that rises and falls in different time increments.

Additionally, the exhaust ports will see different pressures. This translates to uneven stress levels on the gaskets, the valves, and even the piston surfaces. Whether this is enough to actually cause any damage I can't say.

What I can say is it would probably be a good idea, even if only for the appearance of your ride, to install matched mufflers.
 
Back
Top