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-   -   Quieting 9 sec. car (https://forums.maxperformanceinc.com/forums/showthread.php?t=883908)

Mike S 01-21-2026 11:54 AM

Quieting 9 sec. car
 
4 Attachment(s)
Winter project is to make the 67 more street friendly. My 10.00 index class requires mufflers. I have been running a 3.5" X pipe and flow master FX mufflers (straight thru) dumped at the axel. It is rather loud on the street. When I start the car in the garage wife hears it in the house 200' away. The drone inside the car is extreme.
I decided to add 3" tailpipes with resonators. I made 3.5" to 3" cutouts after the mufflers. Also I made divertors to direct the exhaust to the tail pipes when cutout are capped. Only thing I couldn't find in stainless was the cutout caps so made them out of 1/4" ss plate.
Car with the tailpipes is 50% quieter. You can actually talk in the car. No louder than my camaro street car. Neighbors will love it.
As soon as the track opens I will do back to back testing with and without tailpipes.

BB70 01-21-2026 03:43 PM

Looks nice ! I like doing exh work.

mysticmissle 01-21-2026 03:49 PM

really well thought out with the deflector and the cutouts, i had never seen anyone start the trip over the axle with a cut out. that is brilliant.

Jay S 01-21-2026 05:38 PM

Nice job!

KGTO 01-21-2026 06:16 PM

That looks amazing! I like the cut out location and deflector as well, great job!

Mike S 01-21-2026 07:07 PM

Really amazed how noisy the roller lifters are when your car is quiet. Must be the link bars.

Was looking into electric cut outs but way to expensive.


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