Resonator or muffler?

[Motomaniac22]

I currently have single stock piling running from cat into a 12" short resonator then pipe running back to a dual tip. I'm wondering what the difference would be with replacing the resonator with a straight through style muffler? I'm sure it will be quieter, but by how much? Would there be less rasp? I know a lot of the exhaust manufacturers use mufflers rather than resonators. So what would the difference be?

[goalieman24]

Mufflers generally make an exhaust sound quieter and less raspy than resonators.

As far as the 'how much' question... that is virtually impossible to respond to. It is a 100% subjective answer.

[Motomaniac22]

Mufflers generally make an exhaust sound quieter and less raspy than resonators.

As far as the 'how much' question... that is virtually impossible to respond to. It is a 100% subjective answer.

Ok. Thank you for the answer though! I don't have the money to drop on an aftermarket exhaust right now but I want to change mine up a little. It's fine down low. Actually almost perfect. But when you get on it and it gets above 3500 it is too raspy.

[alphaVR]

Resonators and mufflers are largely the same thing, but theyre called different names because theyre doing a slightly different job.

Generally speaking, the resonator you have and the muffler you speak of are both straight through mufflers. The difference comes in at the frequencies they target. The length, cross sectional area, and packing material all go into how the resonator/muffler perform and the frequencies they'll take care of. A round muffler will target a very specific set of frequencies whereas an oval muffler will target a different set. This is because the radius from the center of the pipe(s) going through the muffler case to the wall of the muffler on the oval muffler vary based on the height/width of the muffler and this radius is part of a function that when taking into consideration the speed of sound and the radius at a given point on the case of the muffler.

To answer you question most directly, what a resonator is doing is reducing rasp since it's performance target is much higher frequencies (small distance from center of pipe to resonator wall). A muffler, as goalieman mentioned, targets lower frequencies and thus most often will quiet the general volume of the exhaust.

At this point, you need to ask yourself what exactly is your end objective is - more specifically, what do you want the exhaust to do? If you want the loudness without the rasp, keep the resonator and no muffler. If you want to have the rasp with reduced volume, get rid of the resonator for a traditional muffler (wider and shorter will work best all around). If you want to take it all down a notch, add a muffler.

Now, I will make mention that you'll likely end up with more audible drone by adding the muffler to the system since you're going to be reducing/emphasizing droning frequencies and there are relatively easy ways to counteract them. However, that's a lot more SCIENCE and money spent to achieve that.

[Motomaniac22]

Currently is a nice tone but too raspy at wot

[alphaVR]

If you have the means to do so without generally ruining your current exhaust, I'd try putting an oval magnaflow pack muffler on in conjunction with your existing resonator. The two working together should yield the same tone but with a dialed back volume and less rasp. I did however forget to ask - are you catless?

[Motomaniac22]

No I'm not catless. Just have stock size piping going from cat to a short 12" resonator then pipe back to a tip. The short resonator is in the same location as the original resonator.

[Motomaniac22]

If you have the means to do so without generally ruining your current exhaust, I'd try putting an oval magnaflow pack muffler on in conjunction with your existing resonator. The two working together should yield the same tone but with a dialed back volume and less rasp. I did however forget to ask - are you catless?

Do you mean something like this as the manga flow muffler?
https://www.magnaflow.com/automotive...oval/products/

[goalieman24]

I don't have the money to drop on an aftermarket exhaust right now but I want to change mine up a little.

I'd say it's worth waiting and saving a few bucks until you have enough.

Trying different muffler/resonator combinations until you're happy can start to add up, especially if you're also paying for someone else to do the cutting/welding. And in the end, it's still just with stock sized piping.
With the prices of SSAC stuff and availability of used exhausts for sale, it shouldn't take long to save up and buy something that is worth it.

[MagnaFlow]

On our cat-back for the B5 S4, we replace that resonator with a 5" round muffler that is very much like this one (part #12866). ("Magnapack" usually refers to our round mufflers.) People in the Audi community use Magnapacks as resonator replacements pretty commonly and on twin-pipe systems, our Tru-X mufflers (also called "Resonated X-pipes") are pretty popular.

alphaVR's notes above hit most of the highlights, though. That's a solid post.