Had to resurrect this thread to give an update. After doing this mod and being initially happy with the results I would NOT RECOMMEND this mod. That's right, I would NOT RECOMMEND it.
Here's why....
First. Although there is more sound and at a deeper pitch it comes with some issues. The section of pipe I cut is actually a pipe within a pipe. When you cut the section out as I did the pipe loses it's rigidity result in an embarrassing rattle on deceleration. The internal pipes themselves will vibrate on decel around 3000rpms and it's loud and annoying. There was a simple fix to this.... open the mufflers back up and weld a bracket between the two cut pipes...RESULT....decel vibration gone.
Second. The bracket solves the decel vibration resulting from the internal outer pipe vibrating. This results in another problem, the inner pipe loses part of it's rigidity from the cut as well. This manifests itself on a mild, but noticeable vibration/echo on acceleration around 1500rpms and again at 3000rpms (why these two ranges is beyond me.) There is a simple solution to this problem.... If you decide to cut the pipe, before you weld in a bracket on the outer internal pipe, place a few welds from the inner pipe to the outer pipe tying the two pipes together, then weld a bracket across the span of the two outer pipes tying them together. This solves the vibrating problem.
It might be worth it to some people to do this mod if, and only if, you do the two things I mentioned above when you first open the muffler. I ended up moding the muffler further to bring it back closer to stock.
The choice is ultimately yours, but I just wanted to give you all the heads up and more information to make that choice.
Cheers
Decided to cut into my stock mufflers to modify them for better sound... Why you ask? Well, besides being a complete moron, I have the tools at my disposal to put them back together and figured.... WTF.....
UPDATE - the inner and outer pipes on the outlet portion of the muffler has fibreglass packing layered between them
Just wanted to share a few pictures of the internals of the stock mufflers for anyone who is interested...
I cut the muffler about 2/3 towards the tips and 1/5 in front of the rear inlet. The muffler has a stainless steel inner skin and an aluminized outer skin.
First and second pictures shows a shot from tip end towards the inlet... You can see the inlet pipe on the right side of the picture and the dual outlet pipes on the left. Towards the back of the muffler is a perforated screen. Behind that screen appears to be a "steel wool" type packing material.
Third picture shows a top down shot of the muffler with the flap pealed back, you can see the dual outlet pipes, the inlet pipe (lower right), and just in front of the inlet pipe is another pipe, about 4 inches long that vents from the rear chamber into the front chamber of the muffler.
****UPDATE**** If you plan on trying this mod you only need to cut the section open BETWEEN the two sets of tack welds, you do not need to cut as far rearward as I did in this picture. You can cut the muffler housing in front of the rear support bracket (there is no support bracket (despite the tack welds) towards the outlet portion of the muffler). Doing this also means that your welds do not have to look pretty because they will be hidden when the mufflers are put back on the car.
Fourth pictures is a shot from the inlet end of the muffler towards the outlet. You can see the outlet pipes. The outlet pipes are a "pipe within a pipe". The inner pipe is perforated and outer pipe is solid and wraps around the inner pipe.
The fifth picture is a top down view again, similar to the ones above. You can see on the right side of the dual outlets the "pipe within a pipe" idea I mentioned. The inner casing of the outlet pipes is open on the right end of the pipes. The outer casing stops about 3/8" from the end of each outlet, and the inner pipe is flared out around it (there is a gap between the inner and outer pipes)
I have several thoughts in mind to increase the "loudness" of the exhaust..... closing off the secondary pipe leading from the rear chamber to the front...or blocking off the perforated screen at the inlet end of the muffler.... or cutting a 1 to 2 inch section out of the two outlet pipes in the forward chamber...
****UPDATE**** Picture shows the section I cut out.
Here's why....
First. Although there is more sound and at a deeper pitch it comes with some issues. The section of pipe I cut is actually a pipe within a pipe. When you cut the section out as I did the pipe loses it's rigidity result in an embarrassing rattle on deceleration. The internal pipes themselves will vibrate on decel around 3000rpms and it's loud and annoying. There was a simple fix to this.... open the mufflers back up and weld a bracket between the two cut pipes...RESULT....decel vibration gone.
Second. The bracket solves the decel vibration resulting from the internal outer pipe vibrating. This results in another problem, the inner pipe loses part of it's rigidity from the cut as well. This manifests itself on a mild, but noticeable vibration/echo on acceleration around 1500rpms and again at 3000rpms (why these two ranges is beyond me.) There is a simple solution to this problem.... If you decide to cut the pipe, before you weld in a bracket on the outer internal pipe, place a few welds from the inner pipe to the outer pipe tying the two pipes together, then weld a bracket across the span of the two outer pipes tying them together. This solves the vibrating problem.
It might be worth it to some people to do this mod if, and only if, you do the two things I mentioned above when you first open the muffler. I ended up moding the muffler further to bring it back closer to stock.
The choice is ultimately yours, but I just wanted to give you all the heads up and more information to make that choice.
Cheers
Decided to cut into my stock mufflers to modify them for better sound... Why you ask? Well, besides being a complete moron, I have the tools at my disposal to put them back together and figured.... WTF.....
UPDATE - the inner and outer pipes on the outlet portion of the muffler has fibreglass packing layered between them
Just wanted to share a few pictures of the internals of the stock mufflers for anyone who is interested...
I cut the muffler about 2/3 towards the tips and 1/5 in front of the rear inlet. The muffler has a stainless steel inner skin and an aluminized outer skin.
First and second pictures shows a shot from tip end towards the inlet... You can see the inlet pipe on the right side of the picture and the dual outlet pipes on the left. Towards the back of the muffler is a perforated screen. Behind that screen appears to be a "steel wool" type packing material.
Third picture shows a top down shot of the muffler with the flap pealed back, you can see the dual outlet pipes, the inlet pipe (lower right), and just in front of the inlet pipe is another pipe, about 4 inches long that vents from the rear chamber into the front chamber of the muffler.
****UPDATE**** If you plan on trying this mod you only need to cut the section open BETWEEN the two sets of tack welds, you do not need to cut as far rearward as I did in this picture. You can cut the muffler housing in front of the rear support bracket (there is no support bracket (despite the tack welds) towards the outlet portion of the muffler). Doing this also means that your welds do not have to look pretty because they will be hidden when the mufflers are put back on the car.
Fourth pictures is a shot from the inlet end of the muffler towards the outlet. You can see the outlet pipes. The outlet pipes are a "pipe within a pipe". The inner pipe is perforated and outer pipe is solid and wraps around the inner pipe.
The fifth picture is a top down view again, similar to the ones above. You can see on the right side of the dual outlets the "pipe within a pipe" idea I mentioned. The inner casing of the outlet pipes is open on the right end of the pipes. The outer casing stops about 3/8" from the end of each outlet, and the inner pipe is flared out around it (there is a gap between the inner and outer pipes)
I have several thoughts in mind to increase the "loudness" of the exhaust..... closing off the secondary pipe leading from the rear chamber to the front...or blocking off the perforated screen at the inlet end of the muffler.... or cutting a 1 to 2 inch section out of the two outlet pipes in the forward chamber...
****UPDATE**** Picture shows the section I cut out.
Last edited:
op:
