Fancy Tech: How to Get Rid of Exhaust Drone, works great!

'10Anamoly · 05-26-2011, 04:52 PM

Typically, 28-30" of length for each pipe will kill a lot of drone from 2300-2900rpms. Mine are 28".

6MT · 05-26-2011, 05:02 PM

And I thought a banana in the tail pipe cured all exhaust woes.

ka8 · 12-25-2011, 11:48 PM

Hello! Not to hijack a thread but...I searched google to fix drone in my Z32TT and somehow found this thread.

My setup is 3'' dp and 3''->2.5'' tp with 2.5'' Greddy SP exhaust. My butt-dyno is saying I gained about 30whp but I do have annoying drone at 2300rpm-2900rpm lol. I have to speed up to 75+ mph to quiet down drone.

Since exhaust diameter is different which diameter should I use for my setup? 2.5'' or 3''? Based on what I've read 28-30'' capped pipe sounds about right? Thanks in advance!

'10Anamoly · 12-26-2011, 02:18 PM

29" Capped tubes (one per side) at 2.5" each. The pipes need to mate to the exhaust at a 90 degree angle but the bends afterwards dont matter as long as the length and diameter are right.

'10Anamoly · 12-29-2011, 06:44 PM

Lemme know if that worked for you bud.

ka8 · 12-30-2011, 07:58 PM

Quote:

Originally Posted by '10Anamoly

Lemme know if that worked for you bud.

Just got this done today. But I was only able to squeeze in 20'' of piping because as you probably know already nothing's easy with Z32's. Well I thought I was going to go back to muffler shop but no need to. About 90% of drone is gone at cruising speeds. Just curious now is there any performance loss with this? I don't mind sacrificing 2-3whp for quiet cabin.

Here's my progress for reference.

https://www.300zxclub.com/showthread.php?t=202092

Thanks for your help.

'10Anamoly · 12-31-2011, 07:13 AM

Glad it helps! I am surprised that 20" helped but thats definately cool.

Cyberium · 12-29-2011, 08:07 PM

Cutting and welding sounds a bit too much... has anyone used Dynamat (or similar material) with F.I Catback to help kill the drone inside the cab? I could care less about it being loud outside =)

blazen · 03-02-2012, 04:22 PM

Just wondering, how long did the install take and how much did the shop charge you to do this?

Juice14 · 08-23-2012, 03:36 PM

so is it possible to fit a 12 in resonator on there?

'10Anamoly · 08-24-2012, 07:40 AM

Install took about 1.5 hours and cost me $220. No performance loss.

TeamARK · 08-24-2012, 01:37 PM

Another thing you guys should look into is widen the diameter for these helmholtz pipes. It covers a wider range in the area of where the drone occurs

boyboydan · 03-21-2013, 08:22 AM

Hi to all!

I went to do some experiment rite aft I read this post, because my muffler drone like hell at 1300-2500rpm!! My pipe is 2-1/2 inch and I had a 2" pipe weld side by side with the main pipe with the length about 1.3 meter. Unfortunately, it still drone at the same rpm.. is there anything else I could do??

Thx for the help!!

DarkJak · 04-08-2013, 01:07 AM

Did you only weld one pipe or both? Pics would probably help.

I've noticed that Motordyne, ARK, and HKS all use Helmholtz resonators that look much smaller than 29" to cancel their drone. Seems like it works. Does anyone know why? And if resonators like that would work in drone reduction when welded onto any other exhaust? It looks much nicer than having long tubes imo.

Nismonerd · 09-13-2016, 01:25 PM

Found this thread while searching for cures for exhaust drone. Gave it a try today and the results are better than I expected. I've got a 2010 NISMO with HFCs and Beluga axle backs. The goal was to reduce the drone between 2500 to 3000rpm. I had the muffler shop install a side branch resonator on each side just before the axle back flanges. Using the formula found in this thread, each branch length is 28in, using 2.25in pipe and capped at the ends. I'm very happy with the results, as the drone at the target rpm range has been reduced by about 80%, and the entire rpm range sounds smoother.

I'm sure others have done this as well as this thread is pretty old. I wasn't aware of this method and just wanted to report that it does work. I know that some aftermarket exhausts come with the resonators, but never thought of fabricating them on exhausts that didn't include them.

The job cost me $125 including parts and labor.

05-26-2011, 04:52 PM	#1 (permalink)
'10Anamoly Track Member Join Date: May 2010 Location: GA Posts: 882 Drives: 2010 370Z BS M6 Rep Power: 18	Typically, 28-30" of length for each pipe will kill a lot of drone from 2300-2900rpms. Mine are 28". __________________ 2013 Ford Mustang GT 374rwhp, 360rwtq SAE / GT500 Axle-Backs / Brembo Pack / Track Pack / Recaros / 6spd

05-26-2011, 05:02 PM	#2 (permalink)
6MT A True Z Fanatic Join Date: May 2009 Location: ITU Zone 2 Posts: 22,459 Drives: Reliant Robin Rep Power: 1792	And I thought a banana in the tail pipe cured all exhaust woes. __________________ Andrew 2009 370Z Sport/Touring 6MT sold 2013 Honda Civic Si coupe D/D

12-25-2011, 11:48 PM	#3 (permalink)
ka8 Base Member Join Date: Dec 2011 Location: SOCAL Posts: 2 Drives: Z32TT Rep Power: 15	Hello! Not to hijack a thread but...I searched google to fix drone in my Z32TT and somehow found this thread. My setup is 3'' dp and 3''->2.5'' tp with 2.5'' Greddy SP exhaust. My butt-dyno is saying I gained about 30whp but I do have annoying drone at 2300rpm-2900rpm lol. I have to speed up to 75+ mph to quiet down drone. Since exhaust diameter is different which diameter should I use for my setup? 2.5'' or 3''? Based on what I've read 28-30'' capped pipe sounds about right? Thanks in advance! Jorbes13 likes this.

12-26-2011, 02:18 PM	#4 (permalink)
'10Anamoly Track Member Join Date: May 2010 Location: GA Posts: 882 Drives: 2010 370Z BS M6 Rep Power: 18	29" Capped tubes (one per side) at 2.5" each. The pipes need to mate to the exhaust at a 90 degree angle but the bends afterwards dont matter as long as the length and diameter are right. __________________ 2013 Ford Mustang GT 374rwhp, 360rwtq SAE / GT500 Axle-Backs / Brembo Pack / Track Pack / Recaros / 6spd

12-29-2011, 06:44 PM	#5 (permalink)
'10Anamoly Track Member Join Date: May 2010 Location: GA Posts: 882 Drives: 2010 370Z BS M6 Rep Power: 18	Lemme know if that worked for you bud. __________________ 2013 Ford Mustang GT 374rwhp, 360rwtq SAE / GT500 Axle-Backs / Brembo Pack / Track Pack / Recaros / 6spd

12-31-2011, 07:13 AM	#7 (permalink)
'10Anamoly Track Member Join Date: May 2010 Location: GA Posts: 882 Drives: 2010 370Z BS M6 Rep Power: 18	Glad it helps! I am surprised that 20" helped but thats definately cool. __________________ 2013 Ford Mustang GT 374rwhp, 360rwtq SAE / GT500 Axle-Backs / Brembo Pack / Track Pack / Recaros / 6spd

12-29-2011, 08:07 PM	#8 (permalink)
Cyberium Enthusiast Member Join Date: Mar 2009 Location: Vermont Posts: 379 Drives: 370z Touring \| Sport Rep Power: 18	Cutting and welding sounds a bit too much... has anyone used Dynamat (or similar material) with F.I Catback to help kill the drone inside the cab? I could care less about it being loud outside =) __________________ Stillen G3 Intakes \| F. I TDX

03-02-2012, 04:22 PM	#9 (permalink)
blazen Base Member Join Date: Feb 2012 Location: nyc Posts: 1 Drives: 08 maxima Rep Power: 15	Just wondering, how long did the install take and how much did the shop charge you to do this?

08-23-2012, 03:36 PM	#10 (permalink)
Juice14 Base Member Join Date: Nov 2011 Location: International Posts: 132 Drives: Red 370Z Rep Power: 15	so is it possible to fit a 12 in resonator on there?

08-24-2012, 07:40 AM	#11 (permalink)
'10Anamoly Track Member Join Date: May 2010 Location: GA Posts: 882 Drives: 2010 370Z BS M6 Rep Power: 18	Install took about 1.5 hours and cost me $220. No performance loss. __________________ 2013 Ford Mustang GT 374rwhp, 360rwtq SAE / GT500 Axle-Backs / Brembo Pack / Track Pack / Recaros / 6spd

08-24-2012, 01:37 PM	#12 (permalink)
TeamARK Track Member Join Date: Jul 2009 Location: CHINO Posts: 957 Drives: Black 350z/370z Rep Power: 18	Another thing you guys should look into is widen the diameter for these helmholtz pipes. It covers a wider range in the area of where the drone occurs

03-21-2013, 08:22 AM	#13 (permalink)
boyboydan Base Member Join Date: Mar 2013 Location: hong kong Posts: 1 Drives: 370z Rep Power: 14	Hi to all! I went to do some experiment rite aft I read this post, because my muffler drone like hell at 1300-2500rpm!! My pipe is 2-1/2 inch and I had a 2" pipe weld side by side with the main pipe with the length about 1.3 meter. Unfortunately, it still drone at the same rpm.. is there anything else I could do?? Thx for the help!!

04-08-2013, 01:07 AM	#14 (permalink)
DarkJak A True Z Fanatic Join Date: Jun 2011 Location: Madison, WI Posts: 1,397 Drives: 2009 370Z Rep Power: 16805	Did you only weld one pipe or both? Pics would probably help. I've noticed that Motordyne, ARK, and HKS all use Helmholtz resonators that look much smaller than 29" to cancel their drone. Seems like it works. Does anyone know why? And if resonators like that would work in drone reduction when welded onto any other exhaust? It looks much nicer than having long tubes imo.

09-13-2016, 01:25 PM	#15 (permalink)
Nismonerd Base Member Join Date: Jan 2016 Location: North Alabama Posts: 37 Drives: 2010 370z Nismo Rep Power: 11	Found this thread while searching for cures for exhaust drone. Gave it a try today and the results are better than I expected. I've got a 2010 NISMO with HFCs and Beluga axle backs. The goal was to reduce the drone between 2500 to 3000rpm. I had the muffler shop install a side branch resonator on each side just before the axle back flanges. Using the formula found in this thread, each branch length is 28in, using 2.25in pipe and capped at the ends. I'm very happy with the results, as the drone at the target rpm range has been reduced by about 80%, and the entire rpm range sounds smoother. I'm sure others have done this as well as this thread is pretty old. I wasn't aware of this method and just wanted to report that it does work. I know that some aftermarket exhausts come with the resonators, but never thought of fabricating them on exhausts that didn't include them. The job cost me $125 including parts and labor. bbermann likes this.

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