We have a first gen V in the shop today!
10-22-2012, 01:17 PM
#2
FormerVendor
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10-22-2012, 07:10 PM
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I'd like to see how these end up too in the drone-factor.
10-22-2012, 08:43 PM
#6
Guys, the "Magnaflow drone" is caused by excitation of the spare tire tub. It's like a gigantic drum placed between the mufflers that resonates at approximately 1800 RPM/2*8=7200 Hz (see Youtube link below for a sound sample). You can get rid of the resonance by applying a damper layer to the tub. If you really want to quiet down the car, well--I'm still trying to get around to doing a writeup. Suffice it to say that it's a $600, 45 pound mod involving spot damper+MLV treatments of the trunk, back seat, and the air gap in the trunk lid.
By the way, sorry about the weird, new-age crap subject on the Youtube link. I searched for a 7 Hz tone and that's what came up first. The quality was solid, so I figured what the heck.
By the way, sorry about the weird, new-age crap subject on the Youtube link. I searched for a 7 Hz tone and that's what came up first. The quality was solid, so I figured what the heck.
Last edited by FuzzyLog1c; 10-22-2012 at 08:49 PM.
10-22-2012, 11:48 PM
#7
Staging Lane
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Another way that helped eliminate the drone in my car was. I laid 2 thin old bath towel in the spare tire space, and put the spare face down, then put the cover on as tight as I could. It didn't completely take all the drone away but it help a pretty decent bit.
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10-23-2012, 08:13 AM
#9
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iam curious to see why corsa doesnt drone then? i have corsa and kooks, and no drone whats so ever.
i do like the sound of the stainless works system alot, if my car wasnt a daily i would have went that route
i do like the sound of the stainless works system alot, if my car wasnt a daily i would have went that route
10-23-2012, 09:41 AM
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10-23-2012, 10:16 AM
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i also have drive by videos on my channel as well if you look through it, some light crusing drviebys, and a heavy throttle pass.
stainless works has more of a rumble and even tone, sounds a bit nicer but there will be drone.
10-23-2012, 10:29 AM
#12
10-23-2012, 02:17 PM
#14
The Magnaflow catback may be merely louder than the Corsa across the board, but it is more likely that the length and diameter of the piping and the construction of the mufflers has resulted in a greater frequency response than a Corsa catback at about 7 kHz, and that that is enough to excite the spare tire tub nicely.
10-23-2012, 03:30 PM
#15
06-23-2013, 08:34 PM
#16
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The fundamental frequency (where the majority of the acoustic energy is located) of a V8 engine will always be at (RPM/2)*8 Hz. Therefore, every exhaust will produce a 7 kHz tone at about 1800 RPM, but that doesn't mean that the tone will be strong enough to excite the 7 kHz resonance of the spare tire tub. There are significant losses involved in the transfer of energy that have to be overcome before the tub will begin resonating.
The Magnaflow catback may be merely louder than the Corsa across the board, but it is more likely that the length and diameter of the piping and the construction of the mufflers has resulted in a greater frequency response than a Corsa catback at about 7 kHz, and that that is enough to excite the spare tire tub nicely.
The Magnaflow catback may be merely louder than the Corsa across the board, but it is more likely that the length and diameter of the piping and the construction of the mufflers has resulted in a greater frequency response than a Corsa catback at about 7 kHz, and that that is enough to excite the spare tire tub nicely.
06-23-2013, 11:02 PM
#17
In this thread, I explain the reasons for drone, and the reason that Corsa does not drone (with pics). Corsa mufflers have built-in anti-resonance chambers across a wide range of frequencies. This is what results in the very crisp sound that some love and others don't:
https://ls1tech.com/forums/cadillac-...ltz-tubes.html
I also explain how I got rid of drone on my car by having anti-resonance pipes welded on before my Magnaflow mufflers.
https://ls1tech.com/forums/cadillac-...ltz-tubes.html
I also explain how I got rid of drone on my car by having anti-resonance pipes welded on before my Magnaflow mufflers.
