Quick drone question
Racer
Joined: Apr 2014
Posts: 405
Likes: 10
I have no idea how popular my set up is. Frankly I dont care. That being said. I stock manifolds, stock cats, stock H pipe and im running the Flowmaster force II absolutely love the way it sounds. A little louder than stock at idle, no drone what so ever.
I can easily talk to my copilot all thru the rpm range. It sounds very aggressive and loud at W.O.T.
I can easily talk to my copilot all thru the rpm range. It sounds very aggressive and loud at W.O.T.
Intermediate
Joined: Dec 2014
Posts: 29
Likes: 1
From: kings mountain north carolina
I agree that the X-pipe helps. I have long tube headers, high flow cats , X-pipe , and corsa mufflers . I have zero drone noise. My car is a convertible and it is quiet with the top up or down.
Burning Brakes
Joined: Jun 2009
Posts: 1,135
Likes: 226
From: Roanoke Indiana
Had just the cat back at first. Added the X pipe later. Made no difference, not that there was anything wrong. Should have left well enough alone. My car is an otherwise bone stock 2001 vert.Corsa said the crossover in the H pipe was the size of a dime. Not true.
Oh yea, no drone ever.
Melting Slicks
Joined: Feb 2009
Posts: 2,857
Likes: 234
From: SW Nuh Hampsha
2018 C5 of Year Finalist
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
From 97 to early 2000 the H pipe section was just a tube welded to the bank runners with a plasma cut hole, the size of a dime 0.625 in., to allow cross scavenging.. Early in 2000 this opening was modified to an inch and a half. Still not as balanced as a full flow X pipe.
Burning Brakes
Joined: Jun 2009
Posts: 1,135
Likes: 226
From: Roanoke Indiana
From 97 to early 2000 the H pipe section was just a tube welded to the bank runners with a plasma cut hole, the size of a dime 0.625 in., to allow cross scavenging.. Early in 2000 this opening was modified to an inch and a half. Still not as balanced as a full flow X pipe.
Was not aware of the change. My car is a 2001, so the cross over is much larger. Never the less, with the otherwise stock A4 convertible, there was no noticeable difference.
Burning Brakes
Joined: Oct 2013
Posts: 1,030
Likes: 72
From: Seminole, FL
Ever see the commercial where the opera singer shatters the glass at a particular note?
That is called Resonant Frequency.
My '99 Coupe is a Great Car, and I've been in love since I bought her.
BUT
My first trip to Connecticut from Boston, via the Mass Turnpike, and I was freaking out.
At 70mph the car DRONED me almost to death.
With the top off, windows down, and stereo blasting, the exhaust drone was unbearable.
Around town, who cares, the frequency is always changing due to acceleration and deceleration, and idle... who cares, it sounds GREAT.
But consistent, persistent, CONSTANT fixed frequency DRONE at speed is almost painful.
I fixed it by changing the Frequency at which the rear body vibrated...
Accidentally, I might add.
I did the insulation in the interior because of the engine and exhaust HEAT.
And I did the entire interior.
Suddenly, the DRONE IS GONE.
I can still HEAR the exhaust, but the BODY is not matching the exhaust any more.
Sounds Great.
I posted because of your statement about the targa roof being on causing the sound.
Targa on only causes you to hear MORE of the sound being created by the BODY.
That is called Resonant Frequency.
My '99 Coupe is a Great Car, and I've been in love since I bought her.
BUT
My first trip to Connecticut from Boston, via the Mass Turnpike, and I was freaking out.
At 70mph the car DRONED me almost to death.
With the top off, windows down, and stereo blasting, the exhaust drone was unbearable.
Around town, who cares, the frequency is always changing due to acceleration and deceleration, and idle... who cares, it sounds GREAT.
But consistent, persistent, CONSTANT fixed frequency DRONE at speed is almost painful.
I fixed it by changing the Frequency at which the rear body vibrated...
Accidentally, I might add.
I did the insulation in the interior because of the engine and exhaust HEAT.
And I did the entire interior.
Suddenly, the DRONE IS GONE.
I can still HEAR the exhaust, but the BODY is not matching the exhaust any more.
Sounds Great.
I posted because of your statement about the targa roof being on causing the sound.
Targa on only causes you to hear MORE of the sound being created by the BODY.
Last edited by ArtGle; Jan 15, 2015 at 07:59 PM. Reason: add statement
Burning Brakes
Joined: Oct 2013
Posts: 1,030
Likes: 72
From: Seminole, FL
"But the drone has been so noticeable to me that I've been driving around thinking that I have this super low pitched motor boat sounding exhaust. Yet today I took the targa top off and the exhaust sounded exactly like I thought it would, a slightly louder throatier version of the stock exhaust. What was the most interesting thing to me though is the fact that I really didn't hear any of the drone or deep rumbles with the targa top off. Yet I did the same trip later today with the top on and the car seemed to drone as it has done on all of my previous rides.
So my question is: Could there be something specific with how the targa top transmits harmonics/vibrations that could be causing my car to sound more droney?
I guess the other question that I have is how exactly would I go about reducing/eliminating this drone? "
See my post above.
So my question is: Could there be something specific with how the targa top transmits harmonics/vibrations that could be causing my car to sound more droney?
I guess the other question that I have is how exactly would I go about reducing/eliminating this drone? "
See my post above.
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Burning Brakes
Joined: Oct 2013
Posts: 1,030
Likes: 72
From: Seminole, FL
No pictures of the rear body area, but I continued this all the way to the hatch lip at the rear, and around the entire sides of the body. The addition of this material (apparently) changed the vibration frequency of the body of the car enough to 'move?' it to some other frequency that isn't bothered by the exhaust vibration (sound). Result being that the car is quieter, without the dreaded DRONE.
Melting Slicks
Joined: Feb 2009
Posts: 2,857
Likes: 234
From: SW Nuh Hampsha
2018 C5 of Year Finalist
From 97 to early 2000 the H pipe section was just a tube welded to the bank runners with a plasma cut hole, the size of a dime 0.625 in., to allow cross scavenging.. Early in 2000 this opening was modified to an inch and a half. Still not as balanced as a full flow X pipe.
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
Ever see the commercial where the opera singer shatters the glass at a particular note?
That is called Resonant Frequency.
My '99 Coupe is a Great Car, and I've been in love since I bought her.
BUT
My first trip to Connecticut from Boston, via the Mass Turnpike, and I was freaking out.
At 70mph the car DRONED me almost to death.
With the top off, windows down, and stereo blasting, the exhaust drone was unbearable.
Around town, who cares, the frequency is always changing due to acceleration and deceleration, and idle... who cares, it sounds GREAT.
But consistent, persistent, CONSTANT fixed frequency DRONE at speed is almost painful.
I fixed it by changing the Frequency at which the rear body vibrated...
Accidentally, I might add.
I did the insulation in the interior because of the engine and exhaust HEAT.
And I did the entire interior.
Suddenly, the DRONE IS GONE.
I can still HEAR the exhaust, but the BODY is not matching the exhaust any more.
Sounds Great.
I posted because of your statement about the targa roof being on causing the sound.
Targa on only causes you to hear MORE of the sound being created by the BODY.
That is called Resonant Frequency.
My '99 Coupe is a Great Car, and I've been in love since I bought her.
BUT
My first trip to Connecticut from Boston, via the Mass Turnpike, and I was freaking out.
At 70mph the car DRONED me almost to death.
With the top off, windows down, and stereo blasting, the exhaust drone was unbearable.
Around town, who cares, the frequency is always changing due to acceleration and deceleration, and idle... who cares, it sounds GREAT.
But consistent, persistent, CONSTANT fixed frequency DRONE at speed is almost painful.
I fixed it by changing the Frequency at which the rear body vibrated...
Accidentally, I might add.
I did the insulation in the interior because of the engine and exhaust HEAT.
And I did the entire interior.
Suddenly, the DRONE IS GONE.
I can still HEAR the exhaust, but the BODY is not matching the exhaust any more.
Sounds Great.
I posted because of your statement about the targa roof being on causing the sound.
Targa on only causes you to hear MORE of the sound being created by the BODY.
Bill aka ET
Last edited by Evil-Twin; Jan 15, 2015 at 11:32 PM.
Burning Brakes
Joined: Oct 2013
Posts: 1,030
Likes: 72
From: Seminole, FL
Quote: "So my question is: Could there be something specific with how the targa top transmits harmonics/vibrations that could be causing my car to sound more droney?"
I reiterate my statement. His comment on "THE TARGA TOP" indicates that the 'drone' is more prominent with the roof on... As Was Mine!!!
With the car "CLOSED", the body vibration with the exhaust is PROMINENT!!!
I wear Hearing Aides provided by the VA because I'm Deaf at High Frequencies.
My Coupe was 100% STOCK when my experience occurred.
Since installation of the insulation, NO PROBLEM.
I reiterate my statement. His comment on "THE TARGA TOP" indicates that the 'drone' is more prominent with the roof on... As Was Mine!!!
With the car "CLOSED", the body vibration with the exhaust is PROMINENT!!!
I wear Hearing Aides provided by the VA because I'm Deaf at High Frequencies.
My Coupe was 100% STOCK when my experience occurred.
Since installation of the insulation, NO PROBLEM.
Safety Car
Joined: Apr 2004
Posts: 3,532
Likes: 79
From: pueblo co
When GM was looking for an aggressive exhaust for the C5 Indy pace car, several manufacturers offered a custom exhaust. IN talking to Corsa design engineers I found that sound can be bent by design but you can not get great idle, great wide open throttle with no drone at cruise.. you can only get two out of three.. because the harmonics of exhaust pulses will not allow the frequency responses to cover all three, each has to be tweaked with chambering.. its a science.. so to get no drone at cruise, you have to sacrifice either WOT, or idle.. Corsa have absolutely no drone. Its important at that critical cruise range of 1400 to 1800 rpm..
Many manufacturers go for the obnoxious idle.. many customers want their car to sound this way at idle.. but they have to pay for it at cruise, with drone.
Some people find that adding an Xpipe helps, but because of the specific design of individual exhaust systems, there is no guarantee.
Some people buy an Xpipe and psychologically makes it seem better. If an Xpipe helps, its only by luck. I wont add any further input into this thread...this is just from my conversation with Corsa engineers..
BTW as many know Corsa Indy Pace car system has a GM part number and makes that exhaust considered stock. Not trying to push the OP toward a Corsa system, just trying to explain why some exhaust systems drone.. I would hate to see the OP buy an Xpipe, waste that money and not correct the problem.. This is the reason that I always say. I can not afford to buy anything too cheap... Corsa exhausts are expensive, there is a reason for that.. extensive research, quality control, and the end product.. that's why they are so popular.
I know plenty of people that will buy a 300 dollar exhaust system that sounds " cherry Bomb " obnoxious with obnoxious drone , and they love it.. e.g. the ricer fart can exhaust that many kids put on their car. to me that noise screams cheap, its certainly not muscle car or exotic...
Many manufacturers go for the obnoxious idle.. many customers want their car to sound this way at idle.. but they have to pay for it at cruise, with drone.
Some people find that adding an Xpipe helps, but because of the specific design of individual exhaust systems, there is no guarantee.
Some people buy an Xpipe and psychologically makes it seem better. If an Xpipe helps, its only by luck. I wont add any further input into this thread...this is just from my conversation with Corsa engineers..
BTW as many know Corsa Indy Pace car system has a GM part number and makes that exhaust considered stock. Not trying to push the OP toward a Corsa system, just trying to explain why some exhaust systems drone.. I would hate to see the OP buy an Xpipe, waste that money and not correct the problem.. This is the reason that I always say. I can not afford to buy anything too cheap... Corsa exhausts are expensive, there is a reason for that.. extensive research, quality control, and the end product.. that's why they are so popular.
I know plenty of people that will buy a 300 dollar exhaust system that sounds " cherry Bomb " obnoxious with obnoxious drone , and they love it.. e.g. the ricer fart can exhaust that many kids put on their car. to me that noise screams cheap, its certainly not muscle car or exotic...
Burning Brakes
Joined: Oct 2013
Posts: 1,030
Likes: 72
From: Seminole, FL
Before the drive to Connecticut, I never gave a thought to exhaust noise. In fact, I LOVED IT !!! It's a HotRod, damn it!!! It's SUPPOSED TO BE LOUD....
I drive it every day during the Boston driving season, from home to work and back and then there's the RECREATIONAL DRIVING. I go up to southern NH, frequently.
After doing the insulation, a drive to Brattleboro, VT was a pure pleasure.
And the blonde in the passenger seat enjoyed every minute of the day.
I drive it every day during the Boston driving season, from home to work and back and then there's the RECREATIONAL DRIVING. I go up to southern NH, frequently.
After doing the insulation, a drive to Brattleboro, VT was a pure pleasure.
And the blonde in the passenger seat enjoyed every minute of the day.