Quad resonated vs. HFC x pipe

[VR1]

Hi all,

I currently have an Macht Schnell catless x pipe (it’s dual resonated) paired with an active autowerke gen 2 axleback.

The exhaust sounds great, but it’s pretty bassy from 1-1.5k rpm. The bass translates into NVH into the cabin which I would like to remove.

I’m currently debating adding two resonators (Vibrant 1792, making my x pipe quad resonated), or adding 2 HFCs in the secondary position (GESI 300 cell GSPORT).

I’ve tried comparing through videos but it’s pretty much impossible to compare sound volumes through video, and I’ve yet to find someone who’s had or heard both. Any recommendations on which option would be better to reduce/eliminate drone, quiet down the system a bit and which would eliminate the low end bassiness?

Thanks!

[nycplumber]

You need HFC to fix that. I am quad resonated currently on BW x pipe

[VR1]

Originally Posted by nycplumber

You need HFC to fix that. I am quad resonated currently on BW x pipe

Got ya, thanks! I’m guessing you have similar NVH/Drone then with your quad resonated setup?

[nycplumber]

Yes. Adding some gesi cats to fix it. My neighbors will be very appreciative lol

[VR1]

Originally Posted by nycplumber

Yes. Adding some gesi cats to fix it. My neighbors will be very appreciative lol

Thinking I’ll do a similar route - debating magnaflow 200 Cell cats or the GESI 300 cell cats. Leaning toward the 200 cell since that’s what they used on the RKP sport system. Interested to get your thoughts on how it sounds once you put them in!

[nycplumber]

I don't have empirical data but from everything I read Gesi is a much higher quality. HJS is the best but fabspeed quoted me $2600 for 2 cats so Gesi it is. I will post videos when I do it

[E92Bean]

I have a BW x pipe with 6 resonators. 2 magnaflow that came with the x pipe, and 4 extras added on (in the primary cat location and right after the X). Zero drone/bass with my corsa rear section, and a very clean exhaust note.

[GOFAST M3]

Originally Posted by E92Bean

I have a BW x pipe with 6 resonators. 2 magnaflow that came with the x pipe, and 4 extras added on (in the primary cat location and right after the X). Zero drone/bass with my corsa rear section, and a very clean exhaust note.

I would love to hear that if you have a clip.

[VR1]

Originally Posted by E92Bean

I have a BW x pipe with 6 resonators. 2 magnaflow that came with the x pipe, and 4 extras added on (in the primary cat location and right after the X). Zero drone/bass with my corsa rear section, and a very clean exhaust note.

Got ya! How big of a difference did adding the resonators make volume wise?

[GOFAST M3]

What about adding HF Cats to the OEM x pipe? OEM X plus Cats seems it would be the quietest HF catted x pipe no?

I am considering buying HF Cats and adding to my OEM X instead of replacing the X.

Edit:
This is the closest I could find, 1:21 mark or so is cold start on Eisenmann Race, OEM X fitted w/AA HF Cats. Seems very reasonable for the race system mated w/HF Cats, but all we get is a cold start comparison. I think I will go this direction paired w/ Borla ATAK.

[GORDON.M3]

Originally Posted by E92Bean

I have a BW x pipe with 6 resonators. 2 magnaflow that came with the x pipe, and 4 extras added on (in the primary cat location and right after the X). Zero drone/bass with my corsa rear section, and a very clean exhaust note.

can you show a photo curious how it looks like lol

[E92Bean]

Originally Posted by GORDON.M3

can you show a photo curious how it looks like lol

Working on a YouTube video of the sound too, haven’t had much time recently! Details are I bought this as is, my friend went through the trouble of adding resonator sets. 1 extra set limited general rasp, but DCT shifts had a rasp he disliked. The second set cleaned up the upshift rasp.

The resonators at the primary cat position do have slight clearance issues, I’ve nicked them on oem ZCP suspension with large speed bumps.

[E92Bean]

Originally Posted by GOFAST M3

I would love to hear that if you have a clip.

Exhaust Setup

Here it is! I have a few examples in the video.

[GOFAST M3]

Sounds great, especially at high RPMs! Thanks for posting.

[VR1]

I added a set of GESI 300 cell cats in the secondary position to my Macht Schnell catless x pipe (basically have recreated the RKP Sport X pipe). The car sounds much better imo than before. About 20% quieter but the drone is mostly gone, NVH is much improved, and the cats filtered out the rasp/low end bass sounds from the catless setup. The catted setup sounds higher pitched imo (due to filtering out the rasp and low end frequencies), and has a much cleaner sound. 15/10 would reccomend.

[MineralWhiteF80]

it's also important to call out that the rear muffler can also introduce low end bass and extreme NVH depending on age, style, and design. It's not just the x-pipe configuration that causes rasp/NVH problems.

I had an RPi GTM axle back exhaust and completely stock x-pipe and the amount of deep low-end bass and NVH that muffler setup caused was INSANE. It would visibly rattle all of the interior panels at idle and below 2500 rpm. It sounded like had two 15" subwoofers in the back, and Im not even joking. Funny thing, was that at redline, the car was the quietest and would get louder the closer to idle you were.

I swapped to the Corsa axle back and test pipes and the car sounds awesome now with zero rasp or unwanted garbage sounds.