Exhaust Drone
07-28-2015, 10:17 AM
#1
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Exhaust Drone
My guess this subject has been discussed previously, however being a newbie to this site and also being a new owner of a C6 (2007) I'm hoping that someone out there has the answer.....ok so purchased said C6 about 2 months ago....have replaced stock GPS system, replaced stock air filter system with K & N system and, a few days ago replaced stock exhaust system with a new axle back SLP Loudmouths, the car sounds awesome, however yes there is a drone, as it is i can bear this but, i just feel if there is a way of getting a better interior sound then why not...one question would be what does the exterior sound like while the interior is getting this drone, hopefully nothing like the droning noise from inside???? I have read that it is possible to ease the drone by using pipes added at a 90 degree angle, or by adding baffles somehow...not really wanting to go down these roads however...so any help on this would be great...thank you
07-28-2015, 10:31 AM
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Seriously, IMHO, the car is going to have drone in the 1400-1600 rpm range. You can change gears, change speed, add an H pipe, X pipe, use sound deadener padding, etc., but there is still going to be drone.
07-28-2015, 10:37 AM
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Yup, where the pipes exit the back of the car put on a 90 and run them vertical up the back. Drone gone.
Seriously, IMHO, the car is going to have drone in the 1400-1600 rpm range. You can change gears, change speed, add an H pipe, X pipe, use sound deadener padding, etc., but there is still going to be drone.
Seriously, IMHO, the car is going to have drone in the 1400-1600 rpm range. You can change gears, change speed, add an H pipe, X pipe, use sound deadener padding, etc., but there is still going to be drone.
07-28-2015, 12:12 PM
#6
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As stated above, Corsa is the system that has the least and that's what I put on mine.
07-28-2015, 02:01 PM
#9
I have to agree with the others recommending Corsa. I had B&B Bullets on my car for over a year and the drone drove me crazy. Put on Corsa Sports and I'm very happy with the exhaust note and absolutely no drone on the hi-way.
As to your question about whether drone is heard outside the car, I would say not - drone is a function of resonance between the exhaust and the car body. Corvettes with the open area behind the seats covered mostly in glass create a great chamber for resonance. You would have to do extensive sound-deadening to eliminate even a portion of the drone. Also, I found "shifting around" the drone doesn't always work, especially with hi-way driving. When you downshift to kick up the rpms to get out of the "drone-zone", the sound of the exhaust is also much louder, so you trade one annoyance for another. I don't mind a loud exhaust around town but traveling for hours with that constant loud noise gets old.
As to your question about whether drone is heard outside the car, I would say not - drone is a function of resonance between the exhaust and the car body. Corvettes with the open area behind the seats covered mostly in glass create a great chamber for resonance. You would have to do extensive sound-deadening to eliminate even a portion of the drone. Also, I found "shifting around" the drone doesn't always work, especially with hi-way driving. When you downshift to kick up the rpms to get out of the "drone-zone", the sound of the exhaust is also much louder, so you trade one annoyance for another. I don't mind a loud exhaust around town but traveling for hours with that constant loud noise gets old.
07-28-2015, 02:19 PM
#10
Safety Car
As to your question about whether drone is heard outside the car, I would say not - drone is a function of resonance between the exhaust and the car body. Corvettes with the open area behind the seats covered mostly in glass create a great chamber for resonance. You would have to do extensive sound-deadening to eliminate even a portion of the drone. Also, I found "shifting around" the drone doesn't always work, especially with hi-way driving. When you downshift to kick up the rpms to get out of the "drone-zone", the sound of the exhaust is also much louder, so you trade one annoyance for another. I don't mind a loud exhaust around town but traveling for hours with that constant loud noise gets old.
- mostly.Drone isn't caused by the exhaust, but by the reaction between the exhaust output and the interior of the car. From the outside it isn't an issue. But inside, low pitched exhausts create "echoes" which bounce around the inside, feed off each other, and make really unpleasant noise.
I couldn't talk to the passenger in my car when I was at 70, in 6th, with a light load on the engine. I love the look/sound of my SLP's (PowerFlo), but the drone was awful.
Fixing it isn't as bad as some people think. In the coupes, you have a 'plastic' tub which forms the bottom of the cargo hatch, plus rear glass which focuses the sound to the front of the car. Imagine putting your head inside a plastic bucket, and having someone constantly beat on the outside with drumsticks.
You need to deaden the tub so it doesn't vibrate (Dynamat, or similar material). Then add a layer over the dampening material to block any sounds from the outside (exhaust, road noise, etc) from entering into the rear hatch (Cascade Audio 4.5, Ensolite, or other closed cell foam barriers).
Takes a few hours, $100, and some nicked fingers (aluminum backing on Dynamat). The drone with my SLP's is 90% gone. I hear the exhaust, but not the sympathetic vibrations causing drone.
(tips: the dampening material doesn't need to cover the entire rear tub - people typically recommend 25 - 50% coverage. It is designed to absorb vibrations in the material, so you just need enough to change the characteristics of the material. But the sound barrier needs to be 100% coverage - imagine a wall of windows. If you close 75% of the windows, you don't block much sound from coming in - gotta close them all to have much effect)
Last edited by WAwatchnut; 07-28-2015 at 02:30 PM.
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07-28-2015, 04:54 PM
#12
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07-28-2015, 05:29 PM
#13
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- mostly.Drone isn't caused by the exhaust, but by the reaction between the exhaust output and the interior of the car. From the outside it isn't an issue. But inside, low pitched exhausts create "echoes" which bounce around the inside, feed off each other, and make really unpleasant noise.
I couldn't talk to the passenger in my car when I was at 70, in 6th, with a light load on the engine. I love the look/sound of my SLP's (PowerFlo), but the drone was awful.
Fixing it isn't as bad as some people think. In the coupes, you have a 'plastic' tub which forms the bottom of the cargo hatch, plus rear glass which focuses the sound to the front of the car. Imagine putting your head inside a plastic bucket, and having someone constantly beat on the outside with drumsticks.
You need to deaden the tub so it doesn't vibrate (Dynamat, or similar material). Then add a layer over the dampening material to block any sounds from the outside (exhaust, road noise, etc) from entering into the rear hatch (Cascade Audio 4.5, Ensolite, or other closed cell foam barriers).
Takes a few hours, $100, and some nicked fingers (aluminum backing on Dynamat). The drone with my SLP's is 90% gone. I hear the exhaust, but not the sympathetic vibrations causing drone.
(tips: the dampening material doesn't need to cover the entire rear tub - people typically recommend 25 - 50% coverage. It is designed to absorb vibrations in the material, so you just need enough to change the characteristics of the material. But the sound barrier needs to be 100% coverage - imagine a wall of windows. If you close 75% of the windows, you don't block much sound from coming in - gotta close them all to have much effect)
07-28-2015, 05:37 PM
#14
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You can get a precut kit for the insulation for a vert or coupe. I put one in my coupe back in 08. Also added some Dynomat. Helps with road noise and heat from the headers/cats.
You can find pretty good instructions here also.
You can find pretty good instructions here also.
07-28-2015, 05:54 PM
#15
Drifting
What about the new Borla ATAK? Thinking of installing the atak or the Corsa Extreme. I just don't know. Maybe i'll wait for Carlisle at the end of August.
07-28-2015, 06:50 PM
#16
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IMHO most all cars with dual exhaust have drone. The louder the exhaust, the louder the drone. But, it is all subjective. As WAwatchnut said "I couldn't talk to the passenger in my car when I was at 70, in 6th, with a light load on the engine. I love the look/sound of my SLP's (PowerFlo), but the drone was awful." I had SLP Powerflos on my '05 and yes, there was a mild (to me) drone at 1400-1600 but, overall, the exhaust was too quite (again, my opinion).
Corsa Sports seem to get the best no/low drone rating. Add those and some sound deadener and it may be what you are looking for.
07-28-2015, 09:57 PM
#17
Melting Slicks
07-28-2015, 10:27 PM
#18
Burning Brakes
Exhaust Drone
When my header/cam (NPP no fuse) car starts to emit a drone, I turn the darn radio off.
Really, at a cruise it's just fine. It's a frigging muscle car.
Really, at a cruise it's just fine. It's a frigging muscle car.
07-29-2015, 07:29 AM
#19
Melting Slicks
The drone in my NPP or my modded Z06 Bi-modes didn't drone much at all with no fuse.
DJ
07-29-2015, 08:34 AM
#20
Burning Brakes
- mostly.Drone isn't caused by the exhaust, but by the reaction between the exhaust output and the interior of the car. From the outside it isn't an issue. But inside, low pitched exhausts create "echoes" which bounce around the inside, feed off each other, and make really unpleasant noise.
I couldn't talk to the passenger in my car when I was at 70, in 6th, with a light load on the engine. I love the look/sound of my SLP's (PowerFlo), but the drone was awful.
Fixing it isn't as bad as some people think. In the coupes, you have a 'plastic' tub which forms the bottom of the cargo hatch, plus rear glass which focuses the sound to the front of the car. Imagine putting your head inside a plastic bucket, and having someone constantly beat on the outside with drumsticks.
You need to deaden the tub so it doesn't vibrate (Dynamat, or similar material). Then add a layer over the dampening material to block any sounds from the outside (exhaust, road noise, etc) from entering into the rear hatch (Cascade Audio 4.5, Ensolite, or other closed cell foam barriers).
Takes a few hours, $100, and some nicked fingers (aluminum backing on Dynamat). The drone with my SLP's is 90% gone. I hear the exhaust, but not the sympathetic vibrations causing drone.
(tips: the dampening material doesn't need to cover the entire rear tub - people typically recommend 25 - 50% coverage. It is designed to absorb vibrations in the material, so you just need enough to change the characteristics of the material. But the sound barrier needs to be 100% coverage - imagine a wall of windows. If you close 75% of the windows, you don't block much sound from coming in - gotta close them all to have much effect)