Exhaust drone
Thread Starter
Pro
Joined: Dec 2004
Posts: 710
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From: Raynham MA
Exhaust drone
I have a 72 350 with Hooker competition headers and side pipes.. It looks like the PO had put some insulation underneath the car between the headers and front floor.. I have a lot of drone inside the cabin.. I think its worse when the tops are on and windows are closed.
What would you say is the best way for me to minimize the drone?
Thoughts:
1. Drill holes/Insulate side pipe inserts more (I have 2 1/4 sweet thunder inserts)
2. Use dynamat or something similar inside cabin under carpet in front and rear compartment.
3. ?
Any suggestions from someone who has been down this road already?
Thanks
What would you say is the best way for me to minimize the drone?
Thoughts:
1. Drill holes/Insulate side pipe inserts more (I have 2 1/4 sweet thunder inserts)
2. Use dynamat or something similar inside cabin under carpet in front and rear compartment.
3. ?
Any suggestions from someone who has been down this road already?
Thanks
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I have a 72 350 with Hooker competition headers and side pipes.. It looks like the PO had put some insulation underneath the car between the headers and front floor.. I have a lot of drone inside the cabin.. I think its worse when the tops are on and windows are closed.
What would you say is the best way for me to minimize the drone?
Thoughts:
1. Drill holes/Insulate side pipe inserts more (I have 2 1/4 sweet thunder inserts)
2. Use dynamat or something similar inside cabin under carpet in front and rear compartment.
3. ?
Any suggestions from someone who has been down this road already?
Thanks
What would you say is the best way for me to minimize the drone?
Thoughts:
1. Drill holes/Insulate side pipe inserts more (I have 2 1/4 sweet thunder inserts)
2. Use dynamat or something similar inside cabin under carpet in front and rear compartment.
3. ?
Any suggestions from someone who has been down this road already?
Thanks
Its lighter then dynamat (a little cheaper too) but its weight to performance ratio is amazing. Does a great job at crushing vibration.
Here's a link to check out it if your interested. There's a 20sqft and a 36 sq ft kit. http://store.tkoperformance.com/1997200412.html
There is also a quick video provided to show you what a 5 inch piece does. Good luck.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Idea #1 sounds like it's worth a shot. Drone is from a certain resonance frequency. If you can change that frequency then it will not be so irritating to you. Insulating the insert and or drilling holes should change that frequency. Without know how it will change it will be a method of trial and error though. Different inserts may be the only solution if idea #1 doesn't work.
I'm guessing your drone is occuring in the 1800 to 2200 RPM range or so?
I like those dead mats too but the drone will still be there from the pipes. May end up being a combo of the two. Drone is also subjective. Drone to one person is just a rumble to another. So you'll have to be the judge.
I'm guessing your drone is occuring in the 1800 to 2200 RPM range or so?
I like those dead mats too but the drone will still be there from the pipes. May end up being a combo of the two. Drone is also subjective. Drone to one person is just a rumble to another. So you'll have to be the judge.
Last edited by REELAV8R; Nov 3, 2016 at 03:08 PM.
Drifting
Joined: Mar 2011
Posts: 1,347
Likes: 121
From: Kernersville NC
I think your hearing the exhaust. Sweet thunders are loud. Hooker glass packs are pretty quite at cruise. They are restrictive under WOT but if you like cruising they are pretty good.
Thread Starter
Pro
Joined: Dec 2004
Posts: 710
Likes: 2
From: Raynham MA
Thanks guys.. Yes they are 2 1/4/ inch sweet thunder inserts.. It seems to be louder with the tops on and windows closed.. almost giving me a headache.. i was thinking its drone.. but maybe its just loud and echoing inside the cabin?
I think my #1 option should be inexpensive.. and with a combination of that and some kind of dead mat or dynamat inside the cabin I'm thinking that *should* help.. My carpet is not so nice so might not be a bad idea to replace it anyway.
Any other suggestions? other than changing the exhaust.. ?
Should I be doing something underneath the car? With padding/sound material?
I think my #1 option should be inexpensive.. and with a combination of that and some kind of dead mat or dynamat inside the cabin I'm thinking that *should* help.. My carpet is not so nice so might not be a bad idea to replace it anyway.
Any other suggestions? other than changing the exhaust.. ?
Should I be doing something underneath the car? With padding/sound material?
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
I put sound deadening material inside the door. Took the door panel off, took off the plastic and stuck it directly to the inside of the outer panel of the door. It's basically a big fiberglass drum for sound. Helped a lot with my sidepipes.
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Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
A product called Fat-mat Mega-mat. Very similar to Dynamat extreme. It's a butyl rubber with foil on it. Peel and stick. There is lots of room inside the door though so a guy could put something much thicker in there.
I may go back in and apply something even thicker to get more sound deadening. Pipes louder now since I upped my CR to 10.6:1.
I may go back in and apply something even thicker to get more sound deadening. Pipes louder now since I upped my CR to 10.6:1.
Last edited by REELAV8R; Nov 4, 2016 at 12:29 PM.
Melting Slicks
Joined: Jun 2016
Posts: 2,979
Likes: 332
From: Woodinville WA
Is there such a thing as H pipes or X pipes with side pipes? -I know they can cancel out and dramatically reduce exhaust drone for normal dual exhaust; just not sure if they're feasible with such huge distances (relatively) between the two tubes with side pipes.
Adam
Adam
Thread Starter
Pro
Joined: Dec 2004
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From: Raynham MA
Thanks Guys. I'll start by pulling the inserts, drilling hole sin them and wrapping with insulation and steel wool.. Then I'll take off the door panels and insulate in there.. See how that helps.. I may even buy a DB level tester so I can see if it really helps.
Thanks
Thanks
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Thanks Guys. I'll start by pulling the inserts, drilling hole sin them and wrapping with insulation and steel wool.. Then I'll take off the door panels and insulate in there.. See how that helps.. I may even buy a DB level tester so I can see if it really helps.
Thanks
Thanks
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Standard fiberglass will just get pounded into dust and exit the pipe in a relatively short period of time.
In my dirt bike muffler packing days I used a stranded fiberglass material that lasted significantly longer. Like this pink stuff.
http://www.motorcycle-superstore.com...FQgMaQod71cOUw
It also comes in a mat made for four stroke bikes, I used either the mat stuff cost more.
Just an idea of what might be available. There may be an automotive specific packing application that will work better.
In my dirt bike muffler packing days I used a stranded fiberglass material that lasted significantly longer. Like this pink stuff.
http://www.motorcycle-superstore.com...FQgMaQod71cOUw
It also comes in a mat made for four stroke bikes, I used either the mat stuff cost more.
Just an idea of what might be available. There may be an automotive specific packing application that will work better.
Last edited by REELAV8R; Nov 5, 2016 at 10:53 PM.
Safety Car
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From: Los Angeles CA