Resonator Bypass review ..
Super Member
Joined: Feb 2003
Posts: 523
Likes: 1
From: Hollywood North
CLK 55 ///AMG Cabrio, ML63 ///AMG
Can't wait to see this thanks. 
Its really not that hard, just make sure you go to a higher end exhaust shop that uses at a MINIMUM stainless steel MIG wire and has satin stainless exhaust piping (preferable 2.75" diameter, but 3.0" will work as well). They can weld custom hangers too. I will try to post pics of mine soon.
I will actually be getting it redone with a Stainless Steel X-pipe (also custom) that will cut out a slightly longer section (before & after the MIG welds and current bypass piping) and do super strong high quality TIG welding instead. I will also have before & after Dyno on a 4WD Mustang Dyno (best dynos for our ML63s, tried to dyno on Dyno Dynamics and the car didn't like it b/c the front & rear rollers were not linked in sync). TIG is not 100% mandatory, especially not for a standard resonator bypass, but for high flow X-pipes you need higher strength welds because the X-merge is combining both sides of the exhaust system into one so all the movement under high forces will place extra strain compared to the stock separate pieces. Also, TIG will never leak, MIG can develop pinhole leaks over time (not a huge issue, you can get them touched up for free, but still its annoying).
Once the shop gets the new dyno up and running I will go ahead and have them do the X-pipe along with before & after dynos do another writeup with pics & dyno charts. Once that is complete then the next step is custom TIG welded downpipes. It could be a month before that happens. I will post pics of my current setup in the mean while along with my Dyno from my most recent tune.
My suggestion is go to a high end fabrication shop in town and see if they will do something for you. They are usually better suited to doing such custom work. Any standard muffler shop will use junk mild steel piping (that rusts), with mild steel MIG wire (which will also rust & leak over time) and kink-bent piping (non-mandrel bent smooth piping).
Usually the best fabrication shops are either Local Domestics (read: muscle car shops), or Imports (read: Turbo shops that custom fab Turbo Manifolds, which require insanely strong welds & piping). They don't mind usually doing a quick side project for a german car here & there, for a small fee of course.
Just my 2 cents
I will actually be getting it redone with a Stainless Steel X-pipe (also custom) that will cut out a slightly longer section (before & after the MIG welds and current bypass piping) and do super strong high quality TIG welding instead. I will also have before & after Dyno on a 4WD Mustang Dyno (best dynos for our ML63s, tried to dyno on Dyno Dynamics and the car didn't like it b/c the front & rear rollers were not linked in sync). TIG is not 100% mandatory, especially not for a standard resonator bypass, but for high flow X-pipes you need higher strength welds because the X-merge is combining both sides of the exhaust system into one so all the movement under high forces will place extra strain compared to the stock separate pieces. Also, TIG will never leak, MIG can develop pinhole leaks over time (not a huge issue, you can get them touched up for free, but still its annoying).
Once the shop gets the new dyno up and running I will go ahead and have them do the X-pipe along with before & after dynos do another writeup with pics & dyno charts. Once that is complete then the next step is custom TIG welded downpipes. It could be a month before that happens. I will post pics of my current setup in the mean while along with my Dyno from my most recent tune.
My suggestion is go to a high end fabrication shop in town and see if they will do something for you. They are usually better suited to doing such custom work. Any standard muffler shop will use junk mild steel piping (that rusts), with mild steel MIG wire (which will also rust & leak over time) and kink-bent piping (non-mandrel bent smooth piping).
Usually the best fabrication shops are either Local Domestics (read: muscle car shops), or Imports (read: Turbo shops that custom fab Turbo Manifolds, which require insanely strong welds & piping). They don't mind usually doing a quick side project for a german car here & there, for a small fee of course.
Just my 2 cents
Super Member
Joined: Feb 2003
Posts: 523
Likes: 1
From: Hollywood North
CLK 55 ///AMG Cabrio, ML63 ///AMG
Can anyone recommend a Shop in Toronto Canada to do this properly? I heard that Hot Rod Scott's is a good one, but he's pricey. Any others?
I have had my ML63 (6.3L V8) for a year now but just recently joined now that I have started modding it. I went ahead and did resonator bypass on the ML63 and it has make the car sound so much better. On the ML63s there is no 2nd cats, only a large primary cat, so the two big canisters underneath the car that look like cats are actually just resonators w/ an expansion chamber to cancel out backfires ...
now that I have removed it, the car sounds MUCH more like the CLK63 black series (just alittle bit less loud and more refined with stock rear mufflers in place.
The modification cost me $250 total including parts & labor and was worth every penny, the car sounds perfect now. I highly recommend it
now that I have removed it, the car sounds MUCH more like the CLK63 black series (just alittle bit less loud and more refined with stock rear mufflers in place.
The modification cost me $250 total including parts & labor and was worth every penny, the car sounds perfect now. I highly recommend it
Junior Member
Joined: Feb 2007
Posts: 34
Likes: 0
any updates?
have you thought about h-pipes?
https://mbworld.org/forums/c63-amg-w...07-h-pipe.html
someone did it with the c63 and noticed no loss of power compared to the x-pipe.
have you thought about h-pipes?
https://mbworld.org/forums/c63-amg-w...07-h-pipe.html
someone did it with the c63 and noticed no loss of power compared to the x-pipe.
Member
Joined: Mar 2013
Posts: 152
Likes: 0
2008 ML63 AMG
Just joined the forum and looking at some options for my 2008 ML63. Looking at doing the resonator delete and would like to see some solid videos of before/after, with an without H or X-pipes and also (more importantly) comments or videos of the increased cabin sounds and/or drone (if any). I would hate to introduce loud drone to a great sounding cabin but I would like to hear a bit more growl so was thinking of doing resonator delete with x-pipe and calling it a day but haven't been able to find decent videos. Found plenty of C63 and E63 videos from outside the cabin but nothing from inside or any info if whether this mod will add drone.
Thanks in advance.
Cheers,
AV
Thanks in advance.
Cheers,
AV
Senior Member
Joined: Nov 2008
Posts: 250
Likes: 0
From: Florida
07' 911 Turbo, 09 ML63
Resonator bypass
I have had my ML63 (6.3L V8) for a year now but just recently joined now that I have started modding it. I went ahead and did resonator bypass on the ML63 and it has make the car sound so much better. On the ML63s there is no 2nd cats, only a large primary cat, so the two big canisters underneath the car that look like cats are actually just resonators w/ an expansion chamber to cancel out backfires ...
now that I have removed it, the car sounds MUCH more like the CLK63 black series (just alittle bit less loud and more refined with stock rear mufflers in place.
The modification cost me $250 total including parts & labor and was worth every penny, the car sounds perfect now. I highly recommend it
EDIT: Picture added
now that I have removed it, the car sounds MUCH more like the CLK63 black series (just alittle bit less loud and more refined with stock rear mufflers in place.
The modification cost me $250 total including parts & labor and was worth every penny, the car sounds perfect now. I highly recommend it
EDIT: Picture added
Can you help on where to order and explain a little more about bypass
I'm new to ml63
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Member
Joined: Mar 2013
Posts: 152
Likes: 0
2008 ML63 AMG
Just did the resonator delete last week on my 2008 ML63. Easy job that any muffler shop can do in less than an hour. Ran me $120. Essentially they cut off the resonators around the middle of the car before the rear axle and then add two equal 18-24" lengths of 3" diameter straight pipe in place of the old resonators. Exhaust sounds great, low and deeper rumble with no drone or any downside in my opinion at all. Great sounding exhaust from a great engine.
Cheers,
AV
Cheers,
AV
Thread Starter
Super Member
Joined: Aug 2012
Posts: 963
Likes: 58
From: USA
CL63 AMG
Glad you finally made the jump! Just wait 2-3 months, you will hear your Exhuast transform over the next few months the more you drive it. It's going to sound amazing. Long road trips help accelerate the break-in process (the hotter you can get the rear mufflers the faster they will break in now that there is a lot more heat reaching them than before).
Cheers
Cheers
Super Member
Joined: Feb 2003
Posts: 523
Likes: 1
From: Hollywood North
CLK 55 ///AMG Cabrio, ML63 ///AMG
Nice! Can you share with us, the name and city/state of the shop?
Thanks.
J/
Thanks.
J/
Just did the resonator delete last week on my 2008 ML63. Easy job that any muffler shop can do in less than an hour. Ran me $120. Essentially they cut off the resonators around the middle of the car before the rear axle and then add two equal 18-24" lengths of 3" diameter straight pipe in place of the old resonators. Exhaust sounds great, low and deeper rumble with no drone or any downside in my opinion at all. Great sounding exhaust from a great engine.
Cheers,
AV
Cheers,
AV
Newbie
Joined: Apr 2013
Posts: 3
Likes: 0
From: Bergen County, NJ
2008 ML63 AMG, 2012 335xi E92
Finally got the resonator deleted on my 08 ML63 and WOW!!
I picked it up from the shop about 3 hours ago and did a little cruising around with my brother in his C63.
The sound is much much better (closer to the C63 exhaust but not quite as loud). WOT exhaust note is incredible with every bit of crackling,burping etc when you depress/release the throttle. Cabin noise is a little louder but the real experience is hearing it from another car or with the windows down (I heard it while I drove my brothers car and he drove my ML).
I haven't heard any drone but haven't driven it enough to make a judgment.
Cant wait for the exhaust to transform and sound even better over the next couple of months.
You really do fall in love all over again.
Will post a sound clip soon.
I picked it up from the shop about 3 hours ago and did a little cruising around with my brother in his C63.
The sound is much much better (closer to the C63 exhaust but not quite as loud). WOT exhaust note is incredible with every bit of crackling,burping etc when you depress/release the throttle. Cabin noise is a little louder but the real experience is hearing it from another car or with the windows down (I heard it while I drove my brothers car and he drove my ML).
I haven't heard any drone but haven't driven it enough to make a judgment.
Cant wait for the exhaust to transform and sound even better over the next couple of months.
You really do fall in love all over again.
Will post a sound clip soon.
Thread Starter
Super Member
Joined: Aug 2012
Posts: 963
Likes: 58
From: USA
CL63 AMG
Give it 3 months of consistent driving, it will sound much much better.
I got the original inspiration from the CLK63 black series. If you look at the OEM exhaust on the CLK63BS, AMG gave it that muscle car sound by simply deleting the resonators from the factory, it's complete straight pipes from the primary cats to the rear mufflers, nothing but straight pipe.
This mod essentially does the same thing but with larger rear w164 mufflers (for a more refined & quieter sound. My ML turns heads now and sounds incredibly meaty and deep. People get out of my way at quick grunt of the throttle lol.
Longer road trips and track time definitely speed up the break in process because it heads up the rear canisters a lot more thereby speeding up the burning exhaust packing process.
You should pick up a couple of HP too as there is no odd shaped expansion chamber as in the ML resonator (it's the only one of the AMGs that has this weird resonator to completely cancell out the backfires, pops, & grunts off throttle. Now my car sounds like a refined black series (only with even more power.)
I got the original inspiration from the CLK63 black series. If you look at the OEM exhaust on the CLK63BS, AMG gave it that muscle car sound by simply deleting the resonators from the factory, it's complete straight pipes from the primary cats to the rear mufflers, nothing but straight pipe.
This mod essentially does the same thing but with larger rear w164 mufflers (for a more refined & quieter sound. My ML turns heads now and sounds incredibly meaty and deep. People get out of my way at quick grunt of the throttle lol.
Longer road trips and track time definitely speed up the break in process because it heads up the rear canisters a lot more thereby speeding up the burning exhaust packing process.
You should pick up a couple of HP too as there is no odd shaped expansion chamber as in the ML resonator (it's the only one of the AMGs that has this weird resonator to completely cancell out the backfires, pops, & grunts off throttle. Now my car sounds like a refined black series (only with even more power.)
Member
Joined: Mar 2013
Posts: 152
Likes: 0
2008 ML63 AMG
No drone whatsoever. Sounds great and brings a smile to my face every morning when it starts up.
Just removing a resonator would not cause a CEL. The secondary cats would be something to be careful with if your state requires emissions testing. Something to keep in mind I guess. Although, my 2008 doesn't have the secondary cats.
Cheers,
AV
Just removing a resonator would not cause a CEL. The secondary cats would be something to be careful with if your state requires emissions testing. Something to keep in mind I guess. Although, my 2008 doesn't have the secondary cats.
Cheers,
AV
Thread Starter
Super Member
Joined: Aug 2012
Posts: 963
Likes: 58
From: USA
CL63 AMG
The ML63s do have a secondary car, but it is fully integrated into the main primary cats. For that reason, doings. Cats on the ML63 is extra tricky business to not getting CEL. It can be done but it's not easy.
Hope that helps
Hope that helps
Thread Starter
Super Member
Joined: Aug 2012
Posts: 963
Likes: 58
From: USA
CL63 AMG
Hey guys,
After one year, absolute ZERO negative effects. In fact, the exhaust got an additional 20% louder from just after doing the mod as the rear muffler "broke in" over time. The car sounds absolutely phenomenal and most ask if I have a high end exhaust system.
On a side note... I am debating on going a fully custom TIG welded high flow mid pipes on the car to extract even more power in a refined way. By keeping stock exhaust manifolds it should keep the sound down quite a bit. I will replace the stock primary/secondary hybrid cats with one high flowing primary. I may possibly integrate a high flow X-pipe as well depending on its design. I think high flow cats with this given design should yield 25-30hp/TQ at the crank. I will make sure it is a bolt on part so I can swap out to the old stock parts if necessary. If they work out well, I am sure the shop I choose will be able to produce more of them using my stock ones as a template (should anyone want them).
My primary concern is actually keeping volume down as much as possible, while increasing power as much as possible.
There is a possibility I will remove my straigh pipe resonator bypass and put in a high flow TIG welded X-pipe and use high flow primary downpipes. Ideally this would be the perfect exhaust system because the X-pipe would help eliminate most of the resonance, as well as, improve the scavenging effects.
I will document and take pictures of the entire process of course.
After one year, absolute ZERO negative effects. In fact, the exhaust got an additional 20% louder from just after doing the mod as the rear muffler "broke in" over time. The car sounds absolutely phenomenal and most ask if I have a high end exhaust system.
On a side note... I am debating on going a fully custom TIG welded high flow mid pipes on the car to extract even more power in a refined way. By keeping stock exhaust manifolds it should keep the sound down quite a bit. I will replace the stock primary/secondary hybrid cats with one high flowing primary. I may possibly integrate a high flow X-pipe as well depending on its design. I think high flow cats with this given design should yield 25-30hp/TQ at the crank. I will make sure it is a bolt on part so I can swap out to the old stock parts if necessary. If they work out well, I am sure the shop I choose will be able to produce more of them using my stock ones as a template (should anyone want them).
My primary concern is actually keeping volume down as much as possible, while increasing power as much as possible.
There is a possibility I will remove my straigh pipe resonator bypass and put in a high flow TIG welded X-pipe and use high flow primary downpipes. Ideally this would be the perfect exhaust system because the X-pipe would help eliminate most of the resonance, as well as, improve the scavenging effects.
I will document and take pictures of the entire process of course.
Junior Member
Joined: Jun 2013
Posts: 23
Likes: 0
ML63 AMG
Finally, I have this done last weekend. Excellent sound and experience as same as you guys said!!! The deep sound is exactly what I want~~~~
Also, I have some pics for people who is going to do this or thinking about it~
Thanks!!!
Also, I have some pics for people who is going to do this or thinking about it~
Thanks!!!
Thread Starter
Super Member
Joined: Aug 2012
Posts: 963
Likes: 58
From: USA
CL63 AMG
Well done shenqjin!! Give it another 2-3 months and the sound will only get better with time.
Mid pipe update:
I will be taking my car into the shop to have a custom set of super high quality bolt on mid-pipes made in the next two weeks. These will be a direct bolt-on factory style replacement for the OEM ones. Once they are completed I will be before & after pictures as well as, before & after dynos. Unfortunately it is very hot in Texas in the number so the before numbers may be slightly lower (especially on Mustang Dyno), but what's important is the overall gains in TQ & HP and where in the powerband these gains occur.
I will be very careful to make the mid pipes designed in a way where the increase in volume will be minimal, but the gains will be maximized (I am looking for maximum power, not maximum sound). I opted to do high flow cat mid-pipes instead of an X-pipe resonator replacement because I do not want to ruine the natural AMG exhaust sound which separates the pulses for that old WW2 fighter plane type sound. Also, at some point the stock cats will fail anyways (typically at 80k-100k miles), so I might as well replace them before they fail and potentially cause damage (which can happen).
I am having the shop use my car as a test bed so you guys can benefit from it and order it directly from them as a mass produced part (my gift to the ML community). . Not sure how much they will cost yet or how much they will charge for final product but they assured me it would be reasonable and cost effective compared to the other options on the market.
Many more updates to come!
Mid pipe update:
I will be taking my car into the shop to have a custom set of super high quality bolt on mid-pipes made in the next two weeks. These will be a direct bolt-on factory style replacement for the OEM ones. Once they are completed I will be before & after pictures as well as, before & after dynos. Unfortunately it is very hot in Texas in the number so the before numbers may be slightly lower (especially on Mustang Dyno), but what's important is the overall gains in TQ & HP and where in the powerband these gains occur.
I will be very careful to make the mid pipes designed in a way where the increase in volume will be minimal, but the gains will be maximized (I am looking for maximum power, not maximum sound). I opted to do high flow cat mid-pipes instead of an X-pipe resonator replacement because I do not want to ruine the natural AMG exhaust sound which separates the pulses for that old WW2 fighter plane type sound. Also, at some point the stock cats will fail anyways (typically at 80k-100k miles), so I might as well replace them before they fail and potentially cause damage (which can happen).
I am having the shop use my car as a test bed so you guys can benefit from it and order it directly from them as a mass produced part (my gift to the ML community).
. Not sure how much they will cost yet or how much they will charge for final product but they assured me it would be reasonable and cost effective compared to the other options on the market.Many more updates to come!
Last edited by ML63 AMG; Jul 10, 2013 at 12:16 AM.
Member
Joined: Mar 2013
Posts: 152
Likes: 0
2008 ML63 AMG
Well done shenqjin!! Give it another 2-3 months and the sound will only get better with time.
Mid pipe update:
I will be taking my car into the shop to have a custom set of super high quality bolt on mid-pipes made in the next two weeks. These will be a direct bolt-on factory style replacement for the OEM ones. Once they are completed I will be before & after pictures as well as, before & after dynos. Unfortunately it is very hot in Texas in the number so the before numbers may be slightly lower (especially on Mustang Dyno), but what's important is the overall gains in TQ & HP and where in the powerband these gains occur.
I will be very careful to make the mid pipes designed in a way where the increase in volume will be minimal, but the gains will be maximized (I am looking for maximum power, not maximum sound). I opted to do high flow cat mid-pipes instead of an X-pipe resonator replacement because I do not want to ruine the natural AMG exhaust sound which separates the pulses for that old WW2 fighter plane type sound. Also, at some point the stock cats will fail anyways (typically at 80k-100k miles), so I might as well replace them before they fail and potentially cause damage (which can happen).
I am having the shop use my car as a test bed so you guys can benefit from it and order it directly from them as a mass produced part (my gift to the ML community). . Not sure how much they will cost yet or how much they will charge for final product but they assured me it would be reasonable and cost effective compared to the other options on the market.
Many more updates to come!
Mid pipe update:
I will be taking my car into the shop to have a custom set of super high quality bolt on mid-pipes made in the next two weeks. These will be a direct bolt-on factory style replacement for the OEM ones. Once they are completed I will be before & after pictures as well as, before & after dynos. Unfortunately it is very hot in Texas in the number so the before numbers may be slightly lower (especially on Mustang Dyno), but what's important is the overall gains in TQ & HP and where in the powerband these gains occur.
I will be very careful to make the mid pipes designed in a way where the increase in volume will be minimal, but the gains will be maximized (I am looking for maximum power, not maximum sound). I opted to do high flow cat mid-pipes instead of an X-pipe resonator replacement because I do not want to ruine the natural AMG exhaust sound which separates the pulses for that old WW2 fighter plane type sound. Also, at some point the stock cats will fail anyways (typically at 80k-100k miles), so I might as well replace them before they fail and potentially cause damage (which can happen).
I am having the shop use my car as a test bed so you guys can benefit from it and order it directly from them as a mass produced part (my gift to the ML community).
. Not sure how much they will cost yet or how much they will charge for final product but they assured me it would be reasonable and cost effective compared to the other options on the market.Many more updates to come!
Looking forward to seeing what your shop comes up with
Thread Starter
Super Member
Joined: Aug 2012
Posts: 963
Likes: 58
From: USA
CL63 AMG
Hello Rippin
Yes correct, high flow cat mid pipes will go from the headers exit to the rear pipes leading toward the catbacks. All 02 sensors will remain along with emissions equipment as well. The spacing of the 02 sensors from the cat itself should eliminate the need to run 02 bung spacers. Most of the time the reason high flow cats cause CEL is stock 02 bung is too close to the cat exit, but if you move it further back that will usually cause them to go away. There should be no CEL issues. I may have them run 300 cell metal core cats just to be safe. Either way the gains should be very healthy.
Replacing one set of cats usually won't increase the sound too much, however, because the cats on the ML63 are totally different than any other AMG, I suspect the increase in noise be greater because you are replacing both primary and secondary restrictive cats with just one set of high flow primaries, the sound increase will be greater than normal. The stock cats limit HP to about 520-530hp because the stock ML63 cats just can't flow much more than that. For that reason it should give much more power between 6000-7200rpm. The tune made a massive difference in the mid range, but top end HP gains weren't nearly as drastic due to the airflow restriction. I am hoping to improve the top end gains as well as boost mid range torque gains even more.
I will update everyone and start a whole new writeup thread once I finally perform the upgrade. I should have more news in the next week or two.
Thanks
Yes correct, high flow cat mid pipes will go from the headers exit to the rear pipes leading toward the catbacks. All 02 sensors will remain along with emissions equipment as well. The spacing of the 02 sensors from the cat itself should eliminate the need to run 02 bung spacers. Most of the time the reason high flow cats cause CEL is stock 02 bung is too close to the cat exit, but if you move it further back that will usually cause them to go away. There should be no CEL issues. I may have them run 300 cell metal core cats just to be safe. Either way the gains should be very healthy.
Replacing one set of cats usually won't increase the sound too much, however, because the cats on the ML63 are totally different than any other AMG, I suspect the increase in noise be greater because you are replacing both primary and secondary restrictive cats with just one set of high flow primaries, the sound increase will be greater than normal. The stock cats limit HP to about 520-530hp because the stock ML63 cats just can't flow much more than that. For that reason it should give much more power between 6000-7200rpm. The tune made a massive difference in the mid range, but top end HP gains weren't nearly as drastic due to the airflow restriction. I am hoping to improve the top end gains as well as boost mid range torque gains even more.
I will update everyone and start a whole new writeup thread once I finally perform the upgrade. I should have more news in the next week or two.
Thanks
Last edited by ML63 AMG; Jul 10, 2013 at 04:56 PM.
