[Diy_efi] Can constant WOT operation destroy a muffler?

[Mike]

At 10:14 AM 6/15/06, you wrote:
>I have an unusual "problem" (if you can even call it that) with my  
>Jeep Wrangler that I think can be attributed to near-constant WOT  
>operation.  Every year, no joke, I have to install a new muffler on  
>my Jeep because the old one cracks underneath in exactly the same  
>spot.  Even after only a few hundred miles of use, you can see the  
>metal casing begin to warp and swell, presumably from high heat.

A crack, in that environment, usually means metal fatigue, this can be
caused by any number of issues, inadequate design, excessive vibration,
resonance dynamics, type of mounting being too rigid or flexing in the
wrong area, leverage due to thermal expansion being aggravated etc etc 

Cheapest thing to do would be to weld it and support it in a different
way, just out of curiousity what revs are you doing at WOT to make
it move ?

If you have the means, I'd suggest (and I dont know for sure how its
mounted at the moment), you consider placing a wide band of steel
or aluminium around it (shouldnt melt even at WOT) and hang this from
the body on a pair of rubber mounts suitably positioned to avoid having
them exposed to too much heat - such as, make the band ends much
wider than the body of the muffler so when the rubber mounts are
screwed in the main bulk of heat rise wont go directly to the rubber mounts.

Ostensibly, you would be moving at WOT, so the muffler wont get hot
enough to melt a wide aluminium band around it and the rubber mounts
will be cooled enough anyway. I would use aluminium as its easier
to shape and drill to the task at hand but thin 1mm thick steel would be
ok...

For rubber mounts, you can use a slice of tyre, seen this very often for
aftermarket mods to exhaust systems, had something similar when I had
a 3" exhaust put through...




Regards from


Mike
Perth, Western Australia
VL Commodore Fuse Rail that wont warp or melt !
Twin tyres for most sedans, trikes and motorcycle sidecars
http://niche.iinet.net.au