Exhaust questions?
Exhaust questions?
Ok guys,
When I bought my truck(2006 5.4) it came with the exhaust already done.
its got a SI/DO Flowmaster 40 series. with 24"x3" Stainless tips.
BUT THE DRONE IS DRIVING ME INSANE!!
I love having the exhaust in the pick up, but hate the drone.
On my old truck(2001 5.4), I had a SI/DO Flowmaster super44 series. with 18"x3.5" tips. It had a little drone, but I was able to live with it.
But the drone on the new truck is just ridiculous.
It sounds decent when accelerating. Not much drone at 40-45. But once I get to highway speeds, 60-70 its just crappy. When I am decelerating, it puts off this popping sound too which I hate.
SO all in all, I guess I'm trying to get at, What exhaust can I get that has minimal drone. I know it won't ever go away completely.
Magnaflow? Flowmaster? X-pipe? H?
Thanks guys.
Tanner
When I bought my truck(2006 5.4) it came with the exhaust already done.
its got a SI/DO Flowmaster 40 series. with 24"x3" Stainless tips.
BUT THE DRONE IS DRIVING ME INSANE!!
I love having the exhaust in the pick up, but hate the drone.
On my old truck(2001 5.4), I had a SI/DO Flowmaster super44 series. with 18"x3.5" tips. It had a little drone, but I was able to live with it.
But the drone on the new truck is just ridiculous.
It sounds decent when accelerating. Not much drone at 40-45. But once I get to highway speeds, 60-70 its just crappy. When I am decelerating, it puts off this popping sound too which I hate.
SO all in all, I guess I'm trying to get at, What exhaust can I get that has minimal drone. I know it won't ever go away completely.
Magnaflow? Flowmaster? X-pipe? H?
Thanks guys.
Tanner
Senior Member
Joined: Jan 2009
Posts: 10,731
Likes: 47
From: Concord, NC
Well how loud do you want it man? A 14" magnaflow is similar loudness to a flow 40 on acceleration, but has less drone and less of an idle volume. I run one with hi flows and it sounds great. Before the high flows, it sounds like something you would like. Also, you want the muffler as close to the rear axle as possible to reduce the reverberations from entering under the cab
Senior Member
Joined: Apr 2007
Posts: 517
Likes: 0
From: Ohio
yea if you have the muffler towards the rear, and the tailpipes exiting out the rear, it shouldn't be too bad at all. I noticed a difference when i took off my tailpipe and routed a new pipe out in front of the rear tire. Noticeably louder and more drone, but nothing i can't live with. also a super 44
Well I'm looking maybe doing a SI/SO Magnaflow muffler. that runs into a Y pipe.
I like the sound of the truck. It could be a little deeper, a little louder possibly.
But I just need to get rid of that dang drone. I just just got up under mine, and the muffler is placed right under the rear seat of my SCab.
I like the placement of my tips as they are. (duals out the back).
I like the sound of the truck. It could be a little deeper, a little louder possibly.
But I just need to get rid of that dang drone. I just just got up under mine, and the muffler is placed right under the rear seat of my SCab.
I like the placement of my tips as they are. (duals out the back).
Senior Member
Joined: Dec 1999
Posts: 1,372
Likes: 12
From: California
Please excuse my long answer.....
Exhaust drone & exhaust noise while both are different by definition, both are created as a result of impactors/promoters. Exhaust drone is that which is caused by harmonics- a soundwave generated which in essence takes the exhaust sound and sends it back up the exhaust system (towards the engine) and is released or transferred into the passenger compartment. This transfer typically happens where large contact areas exist that have little to no sound dampening qualities and/or materials- as a result of the muffler construction or vehicle manufacturer.
Exhaust Noise (in passenger compartment) is what most people actually complain about. While harmonics do play a contributive role, it is not the primary cause.
Impactors/Promoters
I would love to tell everyone that “x” is the cause 99% of the time for exhaust noise complaints, but it is typically a series or combination of numerous factors which leads or develops the level of noise which is uncomfortable to the ear. The first “rule” of an exhaust system is that the noise should be generated at the point of discharge (ie tailpipe tip). Obviously, if the tip terminates at your door or immediately under the passenger compartment, the sound level will be much greater at the exhaust discharge point than if the tip exits the rear of the vehicle, but this is common sense.
Assuming that there are no exhaust system leaks and isolators are correctly installed at all mounting points, what is not acceptable by industry standards, is when an exhaust system has been installed correctly, exiting well past the passenger compartment to have substantial exhaust sound transfer into the passenger compartment at a level which does not allow a person to talk without raising their voice to well above ambient noise levels. Whether you love to hear your engine roar (which I do), stereo blast or have a conversation, this interfers with your ability to enjoy what you like.
Now for the Causes
The first problem is most muffler shop staff today have little to no knowledge of exhaust systems, the “tricks” to installing a system that will “please” the customer, and simply verbally repeat the marketing materials provided to them by the system manufacturer. As previously noted by several others, there are 3 basic muffler designs, Absorption, Diffusion, and Chamber (Resonator), no matter which one suits your ear best, the criteria for promoting unnecessary in-cabin noise is the same.
Impactors:
Exhaust system material thickness should be no less than 16 gauge- double-walled pipe was commonly available through the 1970’s until manufacturers began seeking ways to reduce costs. Many of the “Muffler Chains” who marketed lifetime warranties always used double-walled pipe before “stainless steel” became the “in-crowd”. If a shop had it available, I would choose double-walled aluminized coated steel or 14 gauge stainless steel (depending on environmental conditions or personal tastes) - it is very quiet, solid and in terms of costs, pipe is pretty cheap, depending on length, 16 gauge aluminum coated runs about $11 to $20 wholesale (depending on diameter), stainless about double for the same gauge.
The muffler should be located as close to the axle (far away from the passenger compartment) as possible, allowing at least 3” of straight run pipe before a bend occurring (if installed to the forward position of the axle), with the overall length as long as possible. In the oem location, 24" will fit fine, located at the head pipe, 30" will fit fine as well and eliminate almost any possibility of drone in this particular location due to the size, length and insulation qualities (and yes, Allied does make units this long).
With regards to the 5.4/4.6 engines, The head-pipe (the pipe installed in between the exhaust manifold and the muffler) should be no greater in inside diameter the 2 7/8”, at 3” it now becomes a contributor.
Duel Tailpipes should be limited to no greater than 2.25” inside diameter, single tailpipes 3” maximum inside diameter- tips which are larger can certainly be installed but should be limited to 12” in length and have a discharge point past any material that may “catch” a soundwave or exhaust. When you exceed these diameters, it now becomes a contributor.
Tailpipe length in general should be as short as possible, minimal bends, etc, terminating past the axle, 1.5" past the body or bumper. Lengths greater than 4 feet promote “drone” (ie harmonics), typically about 3 ½ feet past the muffler.
Pipe diameter reduction should occur before the muffler. While many muffler installers like to use mufflers which reduce pipe diameter or split the exhaust at the point of discharge at the muffler, or install reducers to connect the tailpipes after the muffler induces “noise”.
Ultimately, it is the quality of the material and the installer which 90% of the time leads to a successful installation. I would like to also emphasize that it is not necessary to spend a fortune on a muffler ($100+) or system to have an excellent sounding, performing and long lasting result.
There are many good mufflers out there, WyoTech, Hot Rod Magazine has numerous published articals on this. On the net, please read:
broaderperformance.com/muffler_flow_tests.htm (Independently tested cfm flows of the more popular mufflers, glasspacks and resonators @ 15” wc:
2 ½” diameter straight pipe 521
2 ¼” diameter straight pipe 365
2” diameter straight pipe 283
2 ¼” diameter tailpipe 268
2 ¼” round glasspack- no louvers 274
2 ¼” round glasspack- with inward punched louvers 133
2 ¼” round glasspack- inward punched louvers/installed backwards 141
2 ½” inlet/outlet Dynomax SuperTurbo 268
2 1/4” inlet/outlet Thrush CVX 260
2 ½” inlet/outlet Flowmaster 2-chamber 249
2 ¼” inlet/2 ½”outlet Cherry Bomb turbo 249
2 ¼” inlet/outlet Flowmaster 3-chamber 229
2 ¼” inlet/2 ½”outlet Maremount Super C (OEM Replacement) 149
2 ¼” inlet/2” dual outlet Maremount 183
2 ¼” inlet/outlet California Turbo 229
2 ½” inlet/outlet Hooker Aerochamber 324
2 ½” inlet/outlet Hooker MaxFlow 521
2 ¼” inlet/outlet Maremount Cherrybomb Vortex 298
2 ½” inlet center/outlet offset Borla Turbo 373
Allied makes an excellent resonator (glasspack style) that has a deep tone, a light rumble, and cost about $40-50, and available at any muffler shop. very high quality and last incredibly long period (20 years on my vehicles)
Exhaust drone & exhaust noise while both are different by definition, both are created as a result of impactors/promoters. Exhaust drone is that which is caused by harmonics- a soundwave generated which in essence takes the exhaust sound and sends it back up the exhaust system (towards the engine) and is released or transferred into the passenger compartment. This transfer typically happens where large contact areas exist that have little to no sound dampening qualities and/or materials- as a result of the muffler construction or vehicle manufacturer.
Exhaust Noise (in passenger compartment) is what most people actually complain about. While harmonics do play a contributive role, it is not the primary cause.
Impactors/Promoters
I would love to tell everyone that “x” is the cause 99% of the time for exhaust noise complaints, but it is typically a series or combination of numerous factors which leads or develops the level of noise which is uncomfortable to the ear. The first “rule” of an exhaust system is that the noise should be generated at the point of discharge (ie tailpipe tip). Obviously, if the tip terminates at your door or immediately under the passenger compartment, the sound level will be much greater at the exhaust discharge point than if the tip exits the rear of the vehicle, but this is common sense.
Assuming that there are no exhaust system leaks and isolators are correctly installed at all mounting points, what is not acceptable by industry standards, is when an exhaust system has been installed correctly, exiting well past the passenger compartment to have substantial exhaust sound transfer into the passenger compartment at a level which does not allow a person to talk without raising their voice to well above ambient noise levels. Whether you love to hear your engine roar (which I do), stereo blast or have a conversation, this interfers with your ability to enjoy what you like.
Now for the Causes
The first problem is most muffler shop staff today have little to no knowledge of exhaust systems, the “tricks” to installing a system that will “please” the customer, and simply verbally repeat the marketing materials provided to them by the system manufacturer. As previously noted by several others, there are 3 basic muffler designs, Absorption, Diffusion, and Chamber (Resonator), no matter which one suits your ear best, the criteria for promoting unnecessary in-cabin noise is the same.
Impactors:
Exhaust system material thickness should be no less than 16 gauge- double-walled pipe was commonly available through the 1970’s until manufacturers began seeking ways to reduce costs. Many of the “Muffler Chains” who marketed lifetime warranties always used double-walled pipe before “stainless steel” became the “in-crowd”. If a shop had it available, I would choose double-walled aluminized coated steel or 14 gauge stainless steel (depending on environmental conditions or personal tastes) - it is very quiet, solid and in terms of costs, pipe is pretty cheap, depending on length, 16 gauge aluminum coated runs about $11 to $20 wholesale (depending on diameter), stainless about double for the same gauge.
The muffler should be located as close to the axle (far away from the passenger compartment) as possible, allowing at least 3” of straight run pipe before a bend occurring (if installed to the forward position of the axle), with the overall length as long as possible. In the oem location, 24" will fit fine, located at the head pipe, 30" will fit fine as well and eliminate almost any possibility of drone in this particular location due to the size, length and insulation qualities (and yes, Allied does make units this long).
With regards to the 5.4/4.6 engines, The head-pipe (the pipe installed in between the exhaust manifold and the muffler) should be no greater in inside diameter the 2 7/8”, at 3” it now becomes a contributor.
Duel Tailpipes should be limited to no greater than 2.25” inside diameter, single tailpipes 3” maximum inside diameter- tips which are larger can certainly be installed but should be limited to 12” in length and have a discharge point past any material that may “catch” a soundwave or exhaust. When you exceed these diameters, it now becomes a contributor.
Tailpipe length in general should be as short as possible, minimal bends, etc, terminating past the axle, 1.5" past the body or bumper. Lengths greater than 4 feet promote “drone” (ie harmonics), typically about 3 ½ feet past the muffler.
Pipe diameter reduction should occur before the muffler. While many muffler installers like to use mufflers which reduce pipe diameter or split the exhaust at the point of discharge at the muffler, or install reducers to connect the tailpipes after the muffler induces “noise”.
Ultimately, it is the quality of the material and the installer which 90% of the time leads to a successful installation. I would like to also emphasize that it is not necessary to spend a fortune on a muffler ($100+) or system to have an excellent sounding, performing and long lasting result.
There are many good mufflers out there, WyoTech, Hot Rod Magazine has numerous published articals on this. On the net, please read:
broaderperformance.com/muffler_flow_tests.htm (Independently tested cfm flows of the more popular mufflers, glasspacks and resonators @ 15” wc:
2 ½” diameter straight pipe 521
2 ¼” diameter straight pipe 365
2” diameter straight pipe 283
2 ¼” diameter tailpipe 268
2 ¼” round glasspack- no louvers 274
2 ¼” round glasspack- with inward punched louvers 133
2 ¼” round glasspack- inward punched louvers/installed backwards 141
2 ½” inlet/outlet Dynomax SuperTurbo 268
2 1/4” inlet/outlet Thrush CVX 260
2 ½” inlet/outlet Flowmaster 2-chamber 249
2 ¼” inlet/2 ½”outlet Cherry Bomb turbo 249
2 ¼” inlet/outlet Flowmaster 3-chamber 229
2 ¼” inlet/2 ½”outlet Maremount Super C (OEM Replacement) 149
2 ¼” inlet/2” dual outlet Maremount 183
2 ¼” inlet/outlet California Turbo 229
2 ½” inlet/outlet Hooker Aerochamber 324
2 ½” inlet/outlet Hooker MaxFlow 521
2 ¼” inlet/outlet Maremount Cherrybomb Vortex 298
2 ½” inlet center/outlet offset Borla Turbo 373
Allied makes an excellent resonator (glasspack style) that has a deep tone, a light rumble, and cost about $40-50, and available at any muffler shop. very high quality and last incredibly long period (20 years on my vehicles)
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