ssmike56

Is there a cheap and easy way to make the stock mufflers on an '06 C6 a little louder? Maybe drill something out? I plan on an NPP upgrade next year but looking for something in the mean time.

kevmcrae

im interested too

bdanyluk

Just cut them off and put on straight pipes. Shouldn't be that loud with the stock exhaust manifolds.

Any muffler shop should be able to do it for $100 or less.

ssmike56

That would be too loud

Sayfoo

https://www.corvetteforum.com/forums...ffler-mod.html

jbrown8238

I did the one Sayfoo references. Skip to page 33-34 for instructions and pictures. Made it sound a bit louder (specially at WOT), little bit of cackle on downshift but no noticeable drone (2005 Convertible). Takes about 15 minutes to do the mod.

ssmike56

Thanks for the link! This is exactly what I'm looking for! I tried doing a search before I posted but came up with a bunch of unrelated threads and didn't see this one.

kevmcrae

I did the drilling in mine tonight. Pretty straight forward. Went to Home Depot and bought a package of 3/4 inch electrical knock out seals, (plugs.) They actually fill a 1 1/16" hole. Also got a 1" bi-metal hole saw with arbor, pilot bit, and a new Milwalkee 1 1/8" step bit because I needed one for the shop anyway. Used the hole saw with some cutting oil to drill through the shell, then all the way through the inner pipe. The step bit cleaned up the outer hole and took off another 1/16". Used some high temp RTV around the outside edge of the hole before tapping in the plug. Want to give it time to cure before I really hit the high RPMs. But start up and light cruising sounds pretty good. Just a bit of rumble. It's a highway cruiser for me so don't want it sounding like my 71 Chevy K20 454 with dual Flowmasters!

ssmike56

Let me know if it drones at all on the highway at 70 or so. Not sure if I want to do 1" or 3/4"

kevmcrae

Put a few hundred miles on the last two days. Definitely like the start up and idle sound better. Does have a tone at 70 ssmike56. Not objectionable for my taste. Seems most evident at roughly 1500 rpms, which is about 70 for me. Louder when going uphill of course, silent going down, flat is about equivalent to a normal hum. Literally, like your humming! I like it. But if you're concerned you could try 3/4 inch first. Can always go bigger, but can't go smaller! Only issue I can foresee is you won't be able to use a bi-metal hole saw the second time. You'd need a step bit but I think I've only seen 7/8 and 1 1/8.

ssmike56

Thanks for the update! I think I'm going to try this mod today with a 7/8" hole saw. I don't mind a little "hum" and 7/& seems like a good start from everyone's reviews.

ssmike56

I just did the muffler mod and the car isn't even on the road yet! Lol! Waiting on the lean release from the bank. Ended up using a 1" all the way through. Sounds good. Just that little extra I was looking for. Thanks for everyone's help and especially the link! Much appreciated!

dmoneychris

Here is a cheap way...to actually get the NPP mufflers, just missing the actuators.
http://killeen.craigslist.org/pts/5180767510.html