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  1. #1

    Default Catalina Exhaust Drone 1970

    I had one of these back in the early 80's with a 350 and the exhaust/engine noise was too much inside! Now I just got another one. What works best to reduce the interior noise? I am looking into dynamat type products. Anyone have any luck with making things quiet inside?

  2. #2
    Join Date
    Oct 2008
    Location
    Portland In
    Posts
    781

    Default

    TRy a quieter muffler or a set of glas****ks hung in the tailpipes as resonators?

    I grew up in a 69 and never noticed it.

    MIke

  3. #3

    Lightbulb Cabin resonance............

    Mike has the right idea: my 462 powered GP has Doug's headers, 2.5" x-pipe, 2.5" X 18" Magnaflows, and full length 2.5" tailpipes, all mandrel bent. I had a terrible resonance inside the car as soon as the trans shifted into top gear @ around 30-40mph. After trying even more restrictive mufflers w/o success, I installed 2.5" inlet X 30" case length, bullet type glas****ks which totally removed the resonance. I butt-welded them into the tailpipes on each side of the gas tank as resonators. I attribute the change to altering the harmonics of the really long exhaust system on this big car, moreso than the quieting of the exhaust note which seemed the same.

    Les
    Attached Images Attached Images
    1966 GTO Sport Coupe
    1968 Grand Prix
    1972 Trans Am clone

  4. #4
    Join Date
    Oct 2008
    Location
    Portland In
    Posts
    781

    Default

    Like Les my 65 G/P with 2.5" exhaust and Pypes Race Pro mufflers would rattle the trunk floor from 2100 to 2500 RPM. I installed a set of glass packs in the tailpipes and the problem is solved.

    MIke

  5. #5

    Default 70 Catalina Station Wagon Exhaust question-

    Quote Originally Posted by Mike Nixon View Post
    Like Les my 65 G/P with 2.5" exhaust and Pypes Race Pro mufflers would rattle the trunk floor from 2100 to 2500 RPM. I installed a set of glass packs in the tailpipes and the problem is solved.

    MIke
    Hey guys, this is my first post to this website and I know this thread is a few years old but figure I'd hit it up and see if I get any responses.
    I just recently purchased a 1970 Catalina Station Wagon ( cheap BDay present to myself). The exhaust is totally shot. I know I can't find headers for this car (I've tried everywhere) so if I were just to replace the exhaust (manifold back) I was thinking something fun like a set of Flowmaster 40's, dump the pipes right out the side near behind the rear doors (if possible) but after reading your responses and having a 68 Bel Air some years back with Flowmaster 40's ( no carpet) I understand the loud droning sound one would experience while hauling at a good speed so figured I'd just get another opinion.

    Also- when you say Glass ...cks- is there any specific brand? Would generic NAPA ones work?

    Thanks, Frank

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