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Exhaust help needed!

Discussion in 'Exhaust' started by JMetro64, Jun 2, 2019.

  1. JMetro64

    JMetro64 Member Established Member

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    I recently just purchased a 2004 cobra and this is the second one I have owned. The car makes about 645 rear wheel horsepower and 560rwtq. The issue I am having is that the car is louder than I would like. It has jba mid length headers, an off-road Mac 3 inch H pipe, and a 3 inch Mac exhaust. It also has a built MMR motor which I'm sure doesn't help either. I bought a used borla touring exhaust to throw on the car hoping that it would solve the problem. But unfortunately it does not line up with the mid pipe, also my shop strongly advised against me going from a 3in exhaust(which I have now) to the 2.5 in borla. So where we are at currently is that I ordered 2 Stainless works turbo chambered mufflers to held in place of the Mac mufflers. I am sceptical about the muffler swapp quieting the car down that much so after hours of research I am contemplating 2 options: 1)going for a 2.5 inch Bassani mid pipe(works with mid length headers) and using my Borla touring catback. Or 2) seeing how it sounds with the new mufflers and if it is too loud, put high flow cats on the mid pipe or see of i can find a 3 inch catted X pipe(which I have not yet). Any recommendations are very appreciated
     
  2. TK1299

    TK1299 Nope Premium Member Established Member

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    Put a stock cat back on it
    Disregard you have 3” exhaust. Sorry
     
  3. HudsonFalcon

    HudsonFalcon Premium Member Premium Member Established Member Beer Money Bros.

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    Tons of exhaust choices out there.

    Go with the 2.5 bassani mid pipe with your Borla touring. That should quiet it down significantly. Is the mid pipe an H pipe and catted?
     
  4. JMetro64

    JMetro64 Member Established Member

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    It's an off road H. Just worried that it'll reduce power a bit. But I guess a 20hp loss is better than a headache
     
  5. HudsonFalcon

    HudsonFalcon Premium Member Premium Member Established Member Beer Money Bros.

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    Yeah sometimes you gotta make a little trade off.

    I went with a MRT catted H pipe with a 3" Bassani cat back and I think I finally found that sweet spot of loudness without being obnoxious.

    I was looking at the Borla Touring at first but couldn't find one.

    Honestly I think your power loss, if any, won't be noticeable.
     
  6. JMetro64

    JMetro64 Member Established Member

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    I was spoiled with my GTRs valved exhaust. push a button and it was full straight pipe, push it again, quieter than stock which was great for long cruises. But yes I too am looking for that sweet spot. I do like the little higher pitch sound of the X pipes, so that may be the best option, especially since I already have the Borla. This would have been much easier if the car had longtubes but I will call Bassani Monday to make sure they will line up with the JLBs.
     
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  7. JMetro64

    JMetro64 Member Established Member

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    Those stainless works turbo chambered mufflers do however sound good imo, just feel it wont be that much quieter. its too bad they don't just sell just the catback for those, the mid pipe they use only work with longtubes or stock manifolds.
     
  8. slo984now

    slo984now AKA 01yellerCobra Established Member

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    There's no reason you can't do something similar on this car. Buddy of mine runs Bassani mids, Bassani O/R X, and Magnaflows. When the cutouts are closed it's almost as quiet as stock. You can have a normal conversation in his car. When the cutouts are open it'll wake the neighborhood up.
     
  9. BLOWN9646

    BLOWN9646 E85 COBRA Established Member

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    You could also try welding some resonators in the mid pipe like some have done
     
  10. GodStang

    GodStang Well-Known Member Established Member

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    3" is a bit big for your current setup. That may be why your Torque seems a bit low. I say run it out 2.5".
     
  11. Comp04svt

    Comp04svt Active Member Established Member

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    IMHO I don't think you'll see much of a power difference going back to a 2.5" cat-back. Like said above I would think you may pick up some torque. Maybe at most loss 5hp.

    The optimum setup would be to swap in some 1-3/4 long tubes and run a 3" x-pipe that's made to mate to the 2.5" cat-back you have. Add some resonators in the x-pipe if you aren't happy with that. See my sig for power numbers and setup, the above is what I run.
     
  12. JMetro64

    JMetro64 Member Established Member

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    that sounds like it would make the most sense. Just a matter of swapping over to the longtubes now.
     
  13. slo984now

    slo984now AKA 01yellerCobra Established Member

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    A long time ago I was doing some reading and I want to say that the smaller catback was actually preferred. By the time the pulse gets to the catback it's cooled down and shrunk. So the smaller pipe help keeps the velocity up.
     

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