D2 A8/S8 (1997 - 2003)
All messages | Search Forums | Return to D2 A8/S8 (1997 - 2003)
I've gone through several revisisions and still not happy with the drone on mine, but getting close
Posted by: alxdgr8 (6515) on 2018-03-12 22:34:53
In Reply to: Custom exhaust posted by lunamar on 2018-03-09 00:18:44

Share | Report
Originally I did an X-Pipe (real X-pipe, not one of the stamped ones) in place of the H-pipe (as close as I could reasonably get it to the cats) and with the OE center resonator and the rear muffler replaced with a straight thru insulated design Milltek rear muffler from a B5 S4. That had all kinds of drone and was like you said, un-driveable.

Rev 2 kept the same forward x-pipe, and then two small bottle resonators (glasspacks essentially) immediately after the x-pipe on each branch, then into a Magnaflow Tru-X muffer in place of the center resonator, and the same Milltek rear muffler. I'm really happy with the 'tone' on this setup, it's a pretty mild OEM+ sort of sound. However there is still a bit too much 100-110Hz drone below 2k rpms, at least for me as a daily driver. I've designed a Helmholtz resonator that I'm going to install on one of the branches between the mid and rear mufflers and hoping that removes the drone. Was hoping to do that soon, but now I have engine problems that are taking priority. A longer rear muffler might be a solution too.

And honestly after all the pain and fab work of getting two pipes to line up all the way back, I should've just gone with a y-pipe and done single 3" or 3.5" all the way back. That probably would've allowed for larger mufflers too which would've helped drone.

MVIMG_20180120_181036<script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
post follow up

You must be registered and logged in to post. Please select an option:

Login with existing account
Create a new account

All messages | Search Forums | Return to D2 A8/S8 (1997 - 2003)