View Full Version : Quieting down 3 inch exhaust

04-14-2008, 05:49 AM
gt28r 3 inch downpipe 3 inch pipe to milltek muffler. The sound is very nice, the drone is really bad. (you can't take the car out for a half hour without getting a headache)

What to do?

Add a mid-muffler? Add a resonator? Add a HFC?

04-14-2008, 06:27 AM
add a mid muffler. I put a Thermal R&D exhaust on my car which is known for the drone, I personally think the drone is due to the 3" midpipe ... at low rpm rates there's not enough flow so the air kinda gets backed up and does not flow properly.

I found that adding a 18" resonator between the downpipe and right before you get to the Y split really helped. It doesn't completely get rid of the drone, but it does make it much much better to the point where it's not really an issue.

I'll be adding a HFC at some point, so we'll see if that changes anything, if anything I would think that should lower the RPM at which it drones, if my theory on why the drone happens is true, since you'll get a bit better flow so the noise point will move lower down.

Hope that helps.


If I remember right, this is what I used.

04-14-2008, 06:29 AM
oops, sorry, I didn't realize you were on a B5 ... so ignore my comment on the Y split since you don't have that. I think my comments still apply.

04-15-2008, 08:33 AM
The muffler is 2.75 the piping is 3 inch. Think the small change in size would cause such bad drone?

Going to try either mid muffler or resonator

04-15-2008, 08:35 AM
mufflers muffle and resonators get rid of drone.

04-25-2008, 07:31 AM
went with vibrant "ultra quiet" 14 inch resonator. It sounds the same $175 later....

04-25-2008, 07:39 AM
Also - Make sure your hangers are working properly. I had an exhaust put together and it had bad drone. I replaced the muffler to quiet things down - the whole thing is non-resonated. The new muffler quieted things down a bit and changed the sound from raspy to a little more sophisticated/metallic, but while I had it suspended with some wire before I could properly fasten it, it still had the drone. When I put in a new hanger and tightened the mounting up, the drone was largely reduced - even without the resonator. It seems that if the exhaust is just hanging and barely supported by the hangers, there may be more resonation/drone, where if it is more securely fastened, the hangers absorb the vibration and remove the drone.

At least it did with my car...

04-25-2008, 08:07 AM
I had the same problem you had with the droning. I have a 3" custom exhaust from the turbo back. I have a HFC right after the turbo. to quiet the droning i installed a 18" or 24" dynomax race muffler in front of the muffler that was already there. It almost completely eliminated the drone. I bought mine from summitracing.com here is the link http://store.summitracing.com/partdetail.asp?autofilter=1&part=WLK%2D24219&N=700+1003+115&autoview=sku[/URL]
It was only $45.00 bucks too!

04-26-2008, 07:59 PM
2 resonators for me= almost no drone.
2.5" turbo back
T28 turbo

04-27-2008, 09:20 AM
mmm without a cat - your car will drone no matter what - trust

04-27-2008, 09:26 AM
mmm without a cat - your car will drone no matter what - trust

very true.

04-27-2008, 10:45 AM
3inch from turbo to flex pipe to cherry bomb 18" to magnaflow muffler. Sounds fuckin awsome. Almost no drone!

04-27-2008, 06:20 PM
Suck it up, be a man and deal with the drone!:)

04-27-2008, 07:42 PM
I am actually getting used to it sounds great at WOT

04-27-2008, 09:38 PM
mmm without a cat - your car will drone no matter what - trust

i have gtrs, 3" tp and 2.5" exhaust.... i believe it has a resonator.