Beautiful . . . but loud exhaust note

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With our Unique Motorcars Cobras many of us notice when we get together with groups of Cobras of all makes, ours have louder and more beautiful sounding exhaust systems. A few of us may have a problem with this (or more likely, a neighbor problem). Patriot Exhaust systems offers a flexible slip in side pipe baffle which could provide an as required and reversible solution to the problem (see www.patriotexhaust.com -- pan down to Muffler Inserts; Standard Insert -- H3842 3 1/2" pipe dia., 7" length and H3840 3 1/2" pipe dia., 12 1/2" length)


  1. ralphscott's Avatar
    Have you tried it? Will it slip into our turn outs?

  2. DCX35's Avatar
    No, the Patriot Exhaust ad sounds as if it would but better double check with www.patriotexhaust.com to be sure. I'm going to do the same before buying. Also I'm going to look up the pipe with a mirror and stiff wire to convince myself there is room enough to accomodate the insert. If there is, I plan to retain it with a sheet metal screw blocking its exit, once installed, screwed in from the inside side of the pipe (out of sight)
  3. ralphscott's Avatar
    Keeps us informed if you go with the insert. My car is quite loud when I get on it and I really don't like to attract attention from the local constables.
  4. DCX35's Avatar
    The local constables will just give you the "thumbs up". . . if you have gray hair. Seems to work.
  5. ralphscott's Avatar
    Not here .... and I've got the gray hair. If I get on it it is like a bitch in heat and the boys come out
  6. Mike Del's Avatar
    The Patriot gizmo doesn't look like a viable option to me.

    I'm using Vortec header inserts. They fit into the collector. The result is a little quieter and more mellow.

    BIG CAM=BIG NOISE If you want quiet buy a LEXUS.
  7. ralphscott's Avatar
    Mike which size did you use. I brought the 3.5 inch with the thought to install them into the pipe outlets but they just can't seem to make the bend.

    Noise control officer's best friend...

  8. Mike Del's Avatar
    Ralph, I used the 3" on my Windsor block headers. Remember I have a 289 style car. Your "bundle of snakes" collector is going to be a problem in the collector. However you should be able to insert them into the turn down at the tail end of the side pipe and bolt them in with a single 1/4" bolt. Tom did it to his car to get through inspection. He had an inspector that was less tolerant than the guy who checked my car.
  9. ralphscott's Avatar
    Couple of Questions Mike. Are the ones Tom installed 3" or 3.5"? Does he have a 427 sidepipes? Did he have to modify them to get them in the turn downs as I can't get mine to make the turn? Last question ..I presume he installed them cone towards the exhaust flow?

  10. Mike Del's Avatar
    Hi Ralph,
    Tom used the 3" also. Slid them into the turn downs (cone tip points toward the engine) and bolted them in with a 1/4" S/S bolt on the inner side of the side pipe. He later removed them and just put the bolt back in to close the hole.
  11. ralphscott's Avatar
    Thanks Mike for the details. I guess I went 1 size too big when I brought them. Did Tom mention why he took them out? Does Tom have the 427 headers or the FIA size headers?

    I am about ready to give the Vortex a try in a smaller size

  12. Mike Del's Avatar
    Tom has a 427 car with the same side pipes that you have Ralph. He wanted a quieter sound level to meet inspection requirements. In the end, he discovered the inspector was not using the correct scale when measuring the sound level, and his car was OK without the baffles. So he removed them. I've had them installed for over four years now without any problem.

  13. ralphscott's Avatar
    Thanks Mike sounds REAL good!

    Another mod to add to my to-do list!

    Let you know how it goes..