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Exhaust help! NA Miata

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  • Exhaust help! NA Miata

    Hello all,

    I have a 95' NA Miata that I bought at the end of last year. It was built as a 'track car' but I use it as a daily driver. My issue is with the excessively loud exhaust. It was cool at first, and understandable for track purposes, but it's getting annoying. Noise wise and the amount of people trying to race me on the street.

    A. I'm not sure what exhaust it is
    B. Best way of silencing? I would prefer not to replace the entire exhaust.

    I believe it's custom, but my knowledge isn't the best. All thoughts are welcome, thanks in advance!

    PICTURES ARE HERE: I put them in google drive because the file size was too large.





    Last edited by Nharpo; 20-05-2017, 02:34 AM.

  • #2
    That rear muffler looks like an absorption type aka "straight through", which would be appropriate for a track car. Replace it with a reactive type muffler, that should sort out your noise issue. You can see a join next to the diff, you would only need to replace from that point back.


    • #3
      how big is your pipe diameter? and have you got a turbo? that downpipe looks exactly the same as my stock rx7 turbo one, while your cat back looks like it could be 2.5". if so that's almost definitely too big for your 1.6L engine (i'm guessing that's your displacement): you'll be losing torque to pointless booming and your exhaust should probably only be 2"or less from your header collector back, but a competent performance exhaust shop should be able to advise you. Too big pipes on naturally aspirated cars is a common problem when racer boy wants "dem tuff sounds", pressure wave exhaust scavenging is totally a thing (you could also look into a helmholz resonator by the way)
      I live my life a quarter mole at a time. Nothing else matters: not the volume, not the temperature, not the lab and all it's bullshit. For those 1.5055 x 10^23 molecules or slightly more, I'm accurate.


      • #4
        Cherry Bomb exhaust is super easy to install and will get the noise level down. As long as you use the glass pack longer then 18"
        Here are some catalogs for you.
        1991 Bronco Eddie Bauer ~ 351w EFI 5.8 (5752cc) ~ E4OD ~ BW1356 (Manual) ~ Manual Hub{s} ~ 265/75 r15