Unfortunately I didnít notice until after I had done the work on the 02 exhaust that the stock exhaust on my 07 has additional heat shields on the outside of the cans. Iím not really sure how much these help with heat dissipation, but I do use soft Cortech saddlebags on a regular basis and I wouldnít want to melt them. At any rate if there is a noticeable difference in heat, the 07 exhaust may require surgery as well. Which means Iíll have an extra gutted exhaust for sale.
The concept behind this was to bypass the baffles without removing them or cutting the end off the cans. (I had much grander plans to begin with but ultimately decided I was too lazy for any of them.) Essentially the gasses pass from the front of the muffler to the rear through a large tube, then they are circulated towards the front again through a smaller tube and finally towards the rear through the 2 smaller exhaust outlets. Someone drew a decent diagram of the inside of the muffler somewhere on this forum if you need a visual. This mod will bypass the extra routing and just travel straight from the front to the back of the exhaust through the one large tube.
So without further ado, here it is!
I'm going to assume that everyone either knows how to remove the exhaust and heat shields or can figure out how to do it by searching around this forum. So I will skip the removal and installation and just deal with the hack and slash part of it.
The first step was to take a hole saw with an inner diameter that just fits over the outlet pipe on the exhaust. Hole saws typically require some material for the center drill bit to go through that keeps the hole saw from ďwanderingĒ. However because the exhaust outlet fits inside the hole saw this is not necessary. That being said drill through the end cap around each exhaust outlet as shown. As long as you have a new sharp hole saw this should be fairly easy.
The second step is to cut off the exhaust outlets as close as possible, it is not necessary to be flush with the end cap of the can however the next step is easier if these are a little shorter.
The third step is by far the most tedious and will require some patience and a steady hand. I used a Dremel tool with a shaft extension and small cutoff wheels. Make sure to buy wheels that are small enough to fit inside the exhaust outlets. If they arenít small enough, just wear them down on a scrap piece of steel until they fit inside. I went through about 5 for each outlet or 20 total, fortunately they are really cheap! I cut off the exhaust outlets about 1Ē into the cans but you could change this as Iím sure it would affect the sound quality in some way (not really sure what it would do?) One of the outlets is curved so it would probably be difficult to cut it off any further than 1Ē inside the can.
Here is the finished product all deburred and ready to have the heat shields reinstalled.
Iíve ridden back and forth to work a few times with them on, and I think I love the sound! Itís taking a little adjusting of my senses because over the last 12,000 miles Iíve become accustomed to the sewing machine quality of noise emitting from the machine beneath me. Iíd be curious to hear the difference between what Iíve done and a fully gutted exhaust, so if thereís anyone in SoCal with a gutted exhaust send me a PM and letís compare and contrast. From the sound clips Iíve heard of a gutted exhaust it certainly seems very similar, but itís really hard to tell from an inexpensive video recording. In the meantime Iíll work on getting a video and sound clip.
Thanks for indulging me,
HERE'S THE CRAPPY VIDEO CLIP!! Pay no attention to the hideous Pontiac Aztec in the background, that belongs to my neighbor. I don't think I'm going to quit my job to become a videographer, but this gives an idea of what it sounds like. After living with this for about a week, I'm LOVIN IT! Staintunes may sound better, but for the price I'm not willing to find out.
Edited by JTG, 07 April 2008 - 08:50 PM.