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"Trumpeting," Causes and Preventions

8K views 13 replies 6 participants last post by  Superman06 
#1 · (Edited)
First let me describe "trumpeting." It is best noted as a sudden increase in noise, around a certain rpm range (generally 2000 rpm but could vary car to car), that occurs just before the car shifts gears (automatics only?). This noise resembles that of a trumpet, hence the name, but can also be related to a bunch of tiny pebbles in a can rattling. In my circumstance it also occurred each time the car reached between 63-67 mph. I referred to that as the "dead" range as I was forced to avoid any speed in that range or else trumpeting would occur. Although very difficult, a person is able to drive around this noise by accelerating very quickly or very slow. This leads me to believe that it is affected by the speed of the exhaust flow throughout the straight pipe setup. As the exhaust travels down the piping, the lack of restriction causes air inside the pipes to bounce up and down creating a vibrating like trumpet sound around certain rpm.

Is anyone familiar with "trupeting" and why it occurs? It is something that becomes present on a car running a cat-less setup. Is trumpeting a result of the mid-pipe itself, or rather the type muffler paired with the mid-pipe? I have experienced a ton of trumpeting when running a cat-less setup paired to a muffler delete. This essentially straight-piped setup caused the trumpeting to become very severe. Is this in direct relation to the mid-pipe itself or due to the lack of a muffler? Would any type of muffler setup still experience this? I have also wondered if other factors such as the type of transmission (Auto/Manual) or the lack of a tune add to the severity.
 
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#2 ·
Sound is a vibration and with no mufflers or cats I suspect the whole exhaust system is vibrating at various harmonic frequencies!!:confused:

FORD has historically used weights (dampers) attached to the system to suppress harmonics......they work hard on exhaust system design to minimize harmonic noise!!:thumb:

I had to put them on my '04 Marauder to suppress exhaust rattle...see photos.......works very well!!:thumb::thumb:
 

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#3 ·
Trumpeting--I'll admit that for half a moment I thought it was some kind of sex thing.


:eek:


;)
 
#7 ·
"Trumpeting," Causes and Preventions

^ to build on that my Roush with only an axelback swap trumpets now. Didn't know until I had some drive it. Swap mufflers and it'll be taken care of.


Pick your poison.
 
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