I posted this in the C5 section but wanted everyone to see it so I'm posting it here too. Mods if this is a problem let me know, thanks.

Ok, so I like the sound of the ti exhaust of the Z06, but I want something louder. Seeing as this is my first Vette, I was surprised at how much $$ exhaust systems, catbacks, even mufflers are for this car. So I started looking for viable alternatives. I knew that I would be fabbing up something myself and installing it on the car to keep it cheap.

The first idea I looked at was the bypass mod on the ti’s. I think that would sound good and be easy, but I don’t have the stuff to do it and don’t know if any of the muffler shops close to me have even heard of titanium exhaust pipe. Besides I don’t want to pay a shop for something I could do myself with some effort and my crude set of rudimentary tools.

The next idea I looked at and listened (online) to was straight pipes after the factory cats and midpipe. I thought with stock catbacks easy to find and cheap I could cut one up and add some pipes and be done. This looked easy enough to do for a diy’er like me but I didn’t think I would like the sound., especially the popping on deceleration or when you rev the engine.

Then I saw a couple of threads on modifying the stock C5 (non ti) mufflers. After seeing the pics of a stock muffler opened up I knew exactly what I wanted to do. Credit to pkmoose ( http://forums.corvetteforum.com/c5-t...-mufflers.html )for these pics:





If you look close you can see there’s a gap in the inlet pipe in the small center chamber of the muffler and the another small section of pipe that directs flow into the rear of the muffler where it has nowhere to go.

Looks to me like this muffler would create a fair amount of backpressure (as well as sound reduction). After reading a thread where the guy opened up the stock muffler from the top and cut off all the pipes flush with the inlet: http://forums.corvetteforum.com/c5-g...ing-out-2.html


Well I knew I wouldn’t like the tin can raspy sound so I came up with an idea to open up the stock mufflers and retain some of their muffling but let them flow better and hopefully sound better and louder.
Here’s my idea - cut out most of the far baffle to expose the outlet pipes to direct pressure from the exhaust bouncing off of the rear of the muffler.



Hopefully this will prevent the raspiness and cut down on the popping. My thinking is that by allowing the exhaust to travel all the way thru the muffler and leaving the inlet and outlet pipes the way they are it will still be like having full use of the muffler. Kind of like a “chambered” muffler (I hope).

So I found a stock uncut set of axle back pipes and mufflers locally on Craigslist for $30:



I cut off the end cap of the stock mufflers:



Here’s what it looks like from the end:



Here’s what I cut out with a drill, sawzall, and dremel:



Then weld the cap back on (I have a flux core wire welder so it is hard to weld sheet metal for me that’s why no close ups of the welds) Took a while and a couple of passes but I got it on and sealed up, ground down and primered with high heat primer:



After the primer dried I painted the welded area with high heat bbq paint to prevent rust:



Now they are ready to go on the car. I’m waiting on some jack pads I ordered to get here and then time off work to do the swap. My plan is to swap the catback in the garage on jackstands. I’ve seen threads where others have done it so I believe I can do it too. I’ll post some clips after I get these installed but I’m not sure when that will be. Just wanted to post up my idea on modding the stock exhaust for any budget minded modders out there. Thoughts?

 

Cool DIY mod, i'll be interested in hearing how it sounds.

Be careful... I remember posts that used words like "scary" and "wouldn't do it again".

 

Yeah I saw that. I think I can pull it off though.

 

That's a pretty good job,lots of effort. I hope you get the sound you're looking for. And be sure to send us a sound sample.

 

Thanks. I don't mind doing the work to save the $$. I figure I can do the bypass mod on these too If I'm not happy with the sound and I'm only out $30, some welding wire and my time.

 

Word of advice - I wouldn't do the swap on jack stands. I'm also the type to DIY everything, and when I swapped mine, I also thought it would be no problem, despite the general opinion. Looking back now, if I need to do it again, I'm just going to take it to a muffler shop and pay them the $50 to let them do it. You can do it on jack stands, no problem, but it's a pain in the ***, and rather unsafe since you need to get it so high. Just my $.02

 

very cool! I am interested in hearing your results as well...

 

Ok I got these on yesterday.
Couple of observations:
1. I am amazed how LIGHT the ti system is. I will be putting that back on in the future with longtubes & x w/ hi flo cats. (It would be really sweet to have a titanium x pipe w/ ti cats!)

2. These mod muffs sound almost exactly like the ti system from inside the car, only slightly louder. (I will probably do the bypass mod on these seeing as it will be easier and I don’t have the stuff to do the ti’s)

3. They aren’t that loud outside the car. Best part is no popping when you let off the gas!

4. I guess I am not used to the exhaust note of the LS series of engines. Seems like finding the sweet spot in sound is difficult.

5. For those who haven’t and are planning to swap your catback yourself: You must have a minimum of 30” from the ground to the bottom of the exhaust tips to get it off without cutting. I had 27 ½” to start with and it wasn’t enough.
On the same note it was a little nerve racking to get the car up that high, but once it was up there doing the work was not bad at all. (My neighbor thought I was crazy) I have been working on my own cars for 27 years so I know to be VERY careful jacking/supporting vehicles before working on them.
All in all it took me 1 hr. and 45 min. start to finish and that’s with having to stop and jack the car up more.

So I tried to take a couple of cell phone vids but the audio is really crappy. In person the exhaust sounds VERY good. Remarkably similar to the ti system - maybe slightly louder.

Idle/Rev:


Drive By:

 

Not bad!