Got the magnaflow stuff installed today. Outside the car, it sounds perfect, very mellow and nice, however I did acquire some interior resonance with it' mostly around the 1500 to 2500 rpm range. I'm not sure if it's the resonator or the mufflers in back but I have a feeling my wife is going to want me to fix it.

Any of you guys running aftmkt exhaust getting some interior resonance with your system?

I ran 2.25" from the cat pipe back, into the 2.25" Magnaflow x-piped resonator out to two Magnaflow mufflers.

Again, sound outside is deep mellow and great but just the resonance. I thought about adding maybe some little bullet resonators to the system inline and seeing if that kills it.

 

Anytime you increase the diameter of the exhaust pipe you are going to introduce more resonance into the system. No way around it. All you can do is add more resonators to reduce it but more than likely it will still be there. I kept all my stock piping aside from the x pipe and the magnaflow mufflers. Sounds awesome and there is no resonance at all.

 

Did you change stock resonators to magnaflow?? Because i just replaced mufflers and it drones too, but not alot!!

 

What mufflers did you get? Im using magnaflows and i have no drone at all. He changed his stock resonators for the magnaflow x-chamber muffler i assume.

 

If it is the sound you want to get rid of, I'd try changing the mufflers to Sebrings (like what FI did) which is also a spiral louvered core design like the Magnaflows, except bigger which is why they muffle the sound a little more. You would essentially have the same components as the FI exhaust.

OR if wifey says it's still too loud, you can go back to the stock mufflers or maybe another chamber style muffler, but lose some performance.

 

thanks for the replies guys. I just wish I knew if the resonance was coming from the resonator or mufflers. I might try to swap out the mufflers to some bigger ones. I did the center - center mufflers and they're straight through as opposed to the stock style offset - center setup. wonder if this has anything to do with the sound, the straight thru part or the tighter bends needed to make the turn. need to look around and search some more. I wasn't aware you could buy mufflers straight from Sebring. Wifey hasn't actually rode in it yet, but I told her to to expect it.

Outside, from what I can tell thus far, it sounds awesome. I'll take some vids outside the car tomorrow for an auible exterior comparison.

 

I use to had stillen before and it's sound great from outside but toomuch for me from the inside.so i replace to stock and add BERK HFC'S Love it.!!!
I will post VDO Clip later. It's soud Deeper and Stock toner was DEEP!!!

 

i might put the stock mufflers back on to test and see if the resonance goes away. if it does, then I'll figure out where to go from there. it's not all that bad but I want to maybe investigate it a little bit.

 

Do you have an aftermarket intake or stock intake.

 

stock intake and all stock otherwise.

 

By "resonance" do you mean drone?

With a louder exhaust setup, it's going to sound louder inside as well. Like you mentioned, some dynomax bullet mufflers may help a bit.

On another v6 car I had, I swapped my flowmaster mufflers (terrible drone) for dynomax and it cut the drone in 1/2.

Some other nice mufflers are dynomax ultraflow. They're straight through mufflers, but have fiberglass inside still, so that helps reduce drone. In my heads/cam/long tube headers Trans Am, it didn't drone. I could still talk on the cell phone no problem inside the car.

Here's a video of the T/A to give you an idea about how mellow the dynomax mufflers are.

http://video.yahoo.com/watch/1596481/5393366

 

It might be the mufflers itself.. FI like terry had mentioned pretty much had the same setup before the sebring mufflers.. any vids?

 

couple of the inside, but none outside yet. give me a couple hours and I'll get something. talked to the exhaust guys this morning, they said they felt it's kinda typical of the magnaflow mufflers and that brand isn't their personal favorite. I do believe the resonance is coming from the mufflers. i'm thinking of maybe installing a 12" or 14" bullet dynomax on each tailpipe section before the muffler to see if it'll knock some of it out. it's not all that bad tho.

I like the idea of swapping to some Sebring mufflers or something, but I don't want to drop $300 in mufflers to see what if. Again it's not bad, in fact, it's very very smooth, zero rasp and sounds killer when revving out. I can live it with it for a bit, but I'm going to try and either tune it out a little or put in a couple of those small thru-flow bullet packs.

 

something like this. small diameter so shouldn't be any problem with fitting it somewhere along a straight section of pipe.

 

Added video.

Here's a youtube of the drone inside the car. Keep in mind, I'm driving at the right speed, right rpms to exaggerate it a lot. Normal driving and I'm through this 'range' somewhat quickly, but this'll give you an idea of what it is.