How much offset for muffler mounting tab is too much?

[rbm]

I'm customizing my BMW K75 and have located a suitable muffler for my build from a 1975 BMW /5. The mounting tab for the /5 muffler is positioned closer to the inlet than the same mounting tab on the stock K75 muffler -- 11-1/2" versus 14". I will have to fabricate a custom bracket anyway to adapt the /5 muffler. The mounting tab's offset from the stock position is 2-1/2" closer meaning the bracket will have a moderate dog-leg shape. Will this be a problem? Is this 2-1/2" too much offset for this application? What I cannot do is insert an extension tube between the exhaust and muffler because it would make the entire length of the exhaust system too long. And I cannot weld on a new bracket because it would damage the chrome.

 

[kopcicle]

Mock it up and they will come ....

Seriously post pics .We have some fine minds here . Give them something to ponder and they will come up with a solution .

~kop

 

[crazypj]

Dogleg will probably be OK but you may need to have double bolts at least one end or it will be able to rotate.
The pipe will be supporting more than it was designed to so may crack?

 

[rbm]

I'll try to illustrate my concern with pictures. At this point in my project, I haven't yet PURCHASED the /5 muffler; only just LOCATED it and now I need this information to make or break the deal.

The K75 stock muffler is a triangular affair with a vertical support plate to which is bolted a hanger. The picture below shows this and also shows the 14" length (NOTE: this is not my muffler; it's a picture from Fleabay. It's only for illustration)

The hanger bolts to the footpeg plate, as illustrated below:

The new muffler has a smaller bracket set back by 11-1/2" and not 14"; as well as a different bracket style, as illustrated below:

So, using one's imagination, the bracket for the new muffler will not line up with the hanger on the footpeg plate, and it will need a new hanger to be fabricated. That offset will be nearly 2-1/2" short of the mounting bolts on the footpeg plate.

So my question is whether I should be concerned with stress or vibration for this muffler installation. I guess if I use thick gauge steel plate when I fabricate the hanger, there will be no concern.

 

[crazypj]

You have dual mounting bolts so it shouldn't be a problem.
I wouldn't use anything thicker than 1/8" steel or 3/16" alloy plate

 

[rbm]

Thank you for the confirmation and the advice, crazypj.

 

[kopcicle]

See ? Told ya ...

~kop