Interior exhaust resonance (3k-4k)

[brlukosk]

I just recently had a custom magnaflow exhaust installed after i finally pieced one together. Pipe is stock ID 2.25" Mid straight through resonator (cheap ass) and magnaflow rear section polished SS muffler, (2.25 in dual 3 out).

Overall it sounds good, REALLY deep. I mean, it sounds like I have a couple of 12" subs in the trunk playing a midbass sweep. It is really loud around 3/4k inside the car, however outside it really isnt that bad.

I was wondering if I should get a better resonator for the mid section from magnaflow, either a magnapack or just a satin straight through.

OR if I should attempt to add some sound deadening in the trunk to get rid of the big loud sweet spot around 3-4000 RPM's. I would probably get some eDead from elemental designs and do the trunk as well as right above the muffler under the car.

Anyone have any experience?

[kjr7888]

I have the same problem with the same setup, getting this installed tomorow, ill let you know

http://vibrantperformance.com/catalo...0c8aa15eb5ed5c

[wood_e]

Try putting in a glasspack. I just installed one today and now my exhaust note is perfect!

[brlukosk]

Try putting in a glasspack. I just installed one today and now my exhaust note is perfect!

I did.

25" Cherry Bomb none the less....

Vibrant res looks nice, but it has a price tag to go with it.

Damn car is anoying. exhaust note sounds amazing except for the interior "sonic boom."

[AudiRacerS4]

its louder inside my car than it is outside and I'm running a 3'' testpipe 2.5'' piping from the turbo back to a magnaflow muffler with no resonators. It sounds great but the drone is ungodly between 3k and 4k but i've become acustomed to it now

[ct1.8t4me]

I have quite a drone as well. I have a 2.5" exhaust from the flexpipe back, no resonator, and a Dynomax muffler in the rear. Mine is definitely louder inside than it is outside.

[brlukosk]

I looked into some sound deadening options.

I think I am going to try liquid eDead from Elemental Designs.

You paint it on as a liquid. I think doing the whole trunk floor with a couple of layers should help quite a bit. I think a lot of the resonance comes from the spare tire well.

[offroader1006]

meh, i like the way it sounds.

its the same pitch as the sax or whatever it is on DMB's Bartender & The Stone.

[Naudilos]

I just got a custom 2.5" exhaust with a 2.5" test pipe, vibrant resonator, and a magnaflow muffler. The drone is way to loud, a lot more loud than I thought it would be. Like most guys state above, the resonance around 3-4K rpm is almost unbearable.

What are a few ideas on how to limit this drone and quite it done a bit???

1. Put stock res back on?
2. Put stock cat back on?
3. ....

[DND]

I've got a 3 inch HFC and 3 inch piping, resonator, and dual 2 1/2 out muffler and the noise is resonating really bad inside the car between 2500 - 3000 rpm.
I really can't go back to stock... so I'm told a bigger resonator is my only option.

[gotaudi]

just turn up the radio that is what i do.

[DND]

The radio won't help prevent the vibration from causing headaches.

[Leifer]

I have a custom cat-back 2.5" with Magnaflow 14815 tips, resonated, and the drone between starts at 2.1K and ends around 3k. It doesn't drone that much on the freeway; it's manageable, but I can see how other people might get irritated because of it.

[Militant-Grunt]

My rear speaker brackets rattle at idle, its soo annoying. I'm 3" turbo back into 3" inlet S4 gutted muffler, funnily enough theres no drone.

[ceas]

the worst droning I've had with my custom magnaflow (no resonator).. was when I was on the highway going uphill in 5th with concrete sound barriers on the sides.. the drone was so bad I felt like my ears were going to explode.

[dualaudi]

anyone think its the custom set up is vibriting on the bottom of the car? My custom setup was great till the stock gutted cat broke at the flange. After we welded it up the drone became super loud.
I think when we welded it back up it got cocked a bit and is now touching more of the body causing the loud hum.

[DND]

My rear speaker brackets rattle at idle, its soo annoying. I'm 3" turbo back into 3" inlet S4 gutted muffler, funnily enough theres no drone.

You're kidding me? None at all? I'm 3" turbo back all the way too and it's horrible between 2500 and 3000. Nothing rattles normally although there is plenty of rumble...
Do you find it loud but just no bad resonance or is it actually not even loud?

the worst droning I've had with my custom magnaflow (no resonator).. was when I was on the highway going uphill in 5th with concrete sound barriers on the sides.. the drone was so bad I felt like my ears were going to explode.

I get interesting acoustics beside concrete barriers or inside parking garages but the headache inducing drone is actually when out in the open at WOT after 2500 RPM.

[Calabria]

Usually the resonator will keep the drone to nothing, maybe a little. Its also about placement of the resonator that helps drone.

[Naudilos]

The radio won't help prevent the vibration from causing headaches.

It sure won't!

So I see a lot of other guys with custom exhaust's are having the same problem, with noise inside the car.

Is a bigger resonator or using the oem resonator the only solution to this??

[quattro_psi]

I to am having this problem. First i installed a custom 2.5" catback with magnaflow muffler and the drone was horrible, so i added a dynomax resonator. That fixed it for about a day til the resonator burned in, and then it was just as bad, has anyone had any luck running two mufflers?

[Naudilos]

Usually the resonator will keep the drone to nothing, maybe a little. Its also about placement of the resonator that helps drone.

So what's the best location for the resonator to help reduce drone?

[fenderstrat1184]

i had the same exact problem 2.5 piping magnaflow muffler... added a glasspack.. really didnt help, i finally lost patience and just gutted everything and got a borla... couldnt be happier

but if you really want things to be quiet go with an apr or milltek if you have the $

[Calabria]

So what's the best location for the resonator to help reduce drone?

That i do not know... but Magnaflow mufflers also create a lot of unwanted turbulence through their mufflers...
Magnaflows B5/6 exhausts are 2.5in to resonator, the, to 2.25in from axle back into a muffler and it supposedly doesnt have any drown. Maybe the pipe break down from 2.5in into 2.25in helps., this also creates more back pressure and less of a bottom end loss aswell.