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Resonance reality

Resonance-

My visit to “The Exhaust Shop”-stkexhst

I showed up and we started talking about what I was looking for in a system. I explained that I wanted the most flow without losing all my back pressure and not creating an unsettling tone. The stock muffler was a “T” where the exhaust flow hit the back of the muffler like a wall and then was forced out either side to exit.

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We agreed on a 2-1/2″ Magnaflow tube into a custom “Y” that provided 2 2-1/4″ outlets out to some 4″ tips.

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I was generally pleased with the results. It sounded good, looked great, and I noticed a bit of difference from the hip dyno.

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As you can see not bad, right? You can hear this one by going to my you tube link page and select “exhaust 1.0 link” or click in the link below.

https://www.youtube.com/watch?v=yWx6XhjRjYc&t=1s

I was happy enough going through the gears and driving on secondary roads. However, in 6th gear at 80 mph the cabin drone was excessive.

The question now was how to retain performance and reduce or eliminate the drone.

Resonance – Wikipedia

https://en.wikipedia.org/wiki/Resonance

In physics, resonance is a phenomenon in which a vibrating system or external force drives another system to oscillate with greater amplitude at specific frequencies. Frequencies at which the response amplitude is a relative maximum are known as the system’s resonant frequencies orresonance frequencies.

THE EXPERTS SAY

After some research it seemed that installing some kind of resonator was going to give me the answer.
But, how much, what type, and where to locate were the questions.  So I turned to “Childs Performance” in Montgomery, AL. They have done a lot of quality work for me over the years. We talked about several ideas and I decided to make this a one trip event and install an 18″ pre muffler and a 21″ (maybe 24″) post muffler stainless steel mesh resonator before the “y”.
resonator
The results were astonishing.
You tube page link exhaust 2.0 is where you can hear that all the noise goes out the back and from the cabin during regular driving it is very tame. Only at higher revs do you hear the race car sound in the cabin. Those are documented on my you tube link page “Barber parade lap short” and “long” video link. By the way, if you have not visited the Barber Motorsports Museum, put it on your list! 1,000s of bikes from wood to steam and all the famous ones. Plus many open wheel racing legends like the John Player special and a lotus collection. Many floors of interesting finds and a must see when in the Birmingham area and a reason to stop buy when you are passing through to the beach. Now onto my tire trepidation.

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