- #1
fastline
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I thought I would try to discuss this here since there seems to be a large misunderstanding in automotive forums and I want to learn the reality, not someone's theory.
basically, I have a car here in which we removed one of the many mufflers. Piping is constructed as 2-1-2. It converges to 1 near the engine, runs through the resonator muffler, out of it about 2ft, to a Y, then 2ft on each side going to the tips.
the overall dbs from this exhaust are not bad but there is a droning noise at 2200rpm. I assume this is hitting the "tuned" resonance if the exhaust system much like a tuning fork and making other sheet metals active in the car. I am not real sure if you could really "eliminate" the resonant frequency but can probably "change" the frequency of resonation?
I have read where some people have cross drilled a hole normal to the exhaust and added a "T" pipe of certain length with a closed end. Some indicate this works like adding pipe length to the system and raising the frequency but I have to wondering if this is actually working on reverse sine cancellation principles or reverse phasing? Basically tuning the length of the this T to reflex a certain frequency of opposite sine or phase in the exhaust note to cancel a certain frequency?
Am I off base here? Would adding mass or weights really help by reducing the resonant frequency?
basically, I have a car here in which we removed one of the many mufflers. Piping is constructed as 2-1-2. It converges to 1 near the engine, runs through the resonator muffler, out of it about 2ft, to a Y, then 2ft on each side going to the tips.
the overall dbs from this exhaust are not bad but there is a droning noise at 2200rpm. I assume this is hitting the "tuned" resonance if the exhaust system much like a tuning fork and making other sheet metals active in the car. I am not real sure if you could really "eliminate" the resonant frequency but can probably "change" the frequency of resonation?
I have read where some people have cross drilled a hole normal to the exhaust and added a "T" pipe of certain length with a closed end. Some indicate this works like adding pipe length to the system and raising the frequency but I have to wondering if this is actually working on reverse sine cancellation principles or reverse phasing? Basically tuning the length of the this T to reflex a certain frequency of opposite sine or phase in the exhaust note to cancel a certain frequency?
Am I off base here? Would adding mass or weights really help by reducing the resonant frequency?
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