IceHammer

So I bought a 2001 SS the other day. Its bone stock with the exception of a magnaflow catback. It makes a nice sound, especially with the windows down. But, with the windows up it kind of resonates in the cabin, which got pretty annoying after a 7hr drive yesterday.

I plan to use this car as a DD, are there any options to tone down the resonating? The outlets to the muffler go to ~16 in long 3 in (maybe 4 in actually) straight tips.

Does the spacing / size of these tips cause the resonating? Or is it all in the muffler? I'd like to get a CME eventually, would the different tip spacing on those change the resonating?

Sladester2

iTrader: (1)

find a Slp Dual/Dual or stock catback because other than that.. magnaflow is pretty much the quietest.

TransAmWS.6

Switching over to different tips might help, however, I have the Magnaflow with the 3.5" tips on my car and I get no resonating, on the highway cruising it almost sounds like it did when it was stock.

MikeWS6

It doesnt get much more tame than a magnaflow. You could always go back to stock.

IceHammer

Well I don't have an issue with volume, so I'm not necessarily looking for a quieter exhaust. It almost sounds like the type of noise you get from a bad wheel bearing, just pulsating when crusing on the highway at an up-hill throttle level.

Its really not a huge deal, I was just curious if anyone had experience with changing their sound based on tips mostly. Or if tips make a difference at all.

jlcustomz

I,ve seen threads here on using a dead ending J-pipe near the muffler, which is pretty much how the new factory camaro mufflers are designed. I didn't fully grasp the formula for figuring pipe length needed, but this is what you, (we) need to do to remove unwanted resonances & leave the exhaust loud.
Research it, figure it out, & explain it to me.
Ps, drop it out of overdrive & see if the noise goes away. At highway speed, mine is horrible at 1600- 2000rpm, but resonance goes away if I'm buzzin @ 3000 plus rpm.

IceHammer

Yes, the resonance (throbbing) noise is much redcuced at 2500+ rpms.

This makes me happy that I'm not the only one with the issue. I googled a little bit and I found a few threads explaining the dead pipe thing (resonator). Lots of people have done this on mustangs apparently. Also there is actually a good thread on the sister truck forum here:

http://www.performancetrucks.net/for...-drone-489463/

He's got a layman's terms explanation in there. This will certainly work, just need to find out the proper lengh of tube for each individual exhaust setup. I don't know if I'll be able to get around to trying this anytime soon. Has anyone else tried this before?

jlcustomz

That article is pretty much what I meant by still don't understand how to figure the length. I do remember now it was on camaro5.com that I saw discussion of this . They used terms like Helzholm frequency if I,m spellin that near correctly. Whenever I get around to this ,I'll probably just pick a length others have used like 23" & try it.
I do understand that it works though, even factory intakes commonly have an area of what we would think to be nothing but dead air space for this reason. Similar principal used in water piping, I removed these 2short dead ending pcs of water pipe near my washer. Later I noticed my sink faucet would squeak & rattle the pipes & didn't know why till years later.