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

Mike · 08-04-2010, 07:13 PM

Wish I knew about this when I had b&b bullets on my C6. Wife would plug her ears with her fingers for the week I had it. Plus rep!

docaam · 08-04-2010, 11:03 PM

Quote:

Originally Posted by '10Anamoly

Yes, you have to use a hole saw to open up a 2" to 2.25" hole on the FI exhaust. That is where the sound waves travel through, down the resonator pipe, and back to cancel out the droning frequencies.

It's a trade off, keep the drone and dont touch the pretty exhaust or mod the exhaust and enjoy the silence (lack of drone, depeche mode style).

Im big Depeche mode fan

.... just trying to prepare myself to get this done as need it badly, lets see if someone with FI exhausts wants to do before me

docaam · 08-10-2010, 03:52 AM

Quote:

Originally Posted by '10Anamoly

Yes, you have to use a hole saw to open up a 2" to 2.25" hole on the FI exhaust. That is where the sound waves travel through, down the resonator pipe, and back to cancel out the droning frequencies.

It's a trade off, keep the drone and dont touch the pretty exhaust or mod the exhaust and enjoy the silence (lack of drone, depeche mode style).

Man when you posted this thread car was in workshop and I have been calculating this drone on rpm range...the vibration starts at 2100 and is there till 2800 depends on the gear and speed as sometime it dies on 2700. Its more if you stay in single gear and accelerate slowly all the way till 3000, but if you push the pedal hard then its a bit less.

So can you throw some light according to your calculations as I have no means to measure those frequencies.

For the pipes does those be in SS or normal exhaust pipe will do the trick. I am about to pull the trigger

by making hole in FI exhausts

'10Anamoly · 08-10-2010, 09:14 AM

Since the FI setup is the same pretty much as mine and the drone in is the same range, I would use 28-30" pipes, one per side. Any shorter and it will tune out drone above 3000rpms where you dont have the problem. Regular steel is fine but I would use some hi-temp paint to keep it from rusting ever.

docaam · 08-10-2010, 09:26 AM

Thanks will plan the operation then

how do you measure like someone would need 28" or 30" or less?

'10Anamoly · 08-10-2010, 10:19 AM

Speed of sound (typically 1100ft/sec, divided by the frequency at which drone occurs, divided by four because you want it to reflect at 1/4 the drone wavelength to cancel it out).

So for drone around 110hz-112hz (around my setup), you get to 2.5 to 2.4 ft, or 29-30".

J. Dub · 10-04-2010, 02:00 PM

So fast intentions CBE drones.... I had no idea. Glad I didn't buy it last week.

TeamARK · 10-04-2010, 02:09 PM

But this exhaust doesn't
ARK PERFORMANCE INC : 370z TRUE DUAL Prototype Teaser w/ dB Test.

Huan'z · 10-04-2010, 03:54 PM

We need to confirm with Tony of f.I and let's see what his advice. I believe Tony tried a Lot of things before he decided to make his cbe. So give him a shot and wait for his respond. That's just only my own idea.

theDreamer · 10-04-2010, 05:52 PM

Quote:

Originally Posted by J. Dub

So fast intentions CBE drones.... I had no idea. Glad I didn't buy it last week.

Might want to check the Fast Intentions thread before making a conclusion. I get mine this week and should have a full review soon, then again there are already over a 100 reviews of the exhaust.

Huan'z · 10-04-2010, 06:30 PM

with thedreamer. And take a look how many sets Tony sell out. I'm one of his customer still waiting for his cbe. And didn't hear anything like drone or whatever negative from other forum member. So let's wait from thedreamer. Hey bro keep us updated. Whenever u got yours and installed. Let me know so I can meet up with u. I want to hear from it and see how's good is it.

phelan · 10-04-2010, 06:50 PM

Quote:

Originally Posted by TeamARK

But this exhaust doesn't
ARK PERFORMANCE INC : 370z TRUE DUAL Prototype Teaser w/ dB Test.

wow, shameless plug much?

Quote:

Originally Posted by '10Anamoly

Speed of sound (typically 1100ft/sec, divided by the frequency at which drone occurs, divided by four because you want it to reflect at 1/4 the drone wavelength to cancel it out).

So for drone around 110hz-112hz (around my setup), you get to 2.5 to 2.4 ft, or 29-30".

So...to get the frequencies of your droning, you put a microphone to your exhaust and ran it through a spectrum analyzer (i.e. Audacity if you're not in a lab...haha) to get the peak frequencies? Out of curiosity, did you run any filters on the output, or was it all raw? How clean was the data?

Nothing serious, just piqued my curiosity. I like reading stuff like this.

XwChriswX · 10-04-2010, 07:09 PM

Quote:

Originally Posted by phelan

Nothing serious, just piqued my curiosity. I like reading stuff like this.

docaam · 10-05-2010, 02:02 AM

Running FI exhausts for few months now, I can say the exhaust sounds awesome but what OP was referring to was not the normal drone (I can live with that) but vibration because of it. I do face that if I accelerate the car slowly(normal crusing) not pushing it hard as rpms has to go steady from 2k to 3k and its there for good 500 - 700, mine starts from 2200 and lasts till 2800.

This thread shouldn't be taken anything against FI as they are an awesome company with awesome product, its just people have their own preferences. My daughter(7yrs) hates this drone and avoid sitting in the car LOL. I went through doing a DYNAMAT sound proofing when upgrading the audio it has reduced this vibration (not talking about drone/sound/noise) but its still there and if Tony gives some input on this thread I am willing to do this DIY

hr350z · 11-04-2010, 09:39 PM

Will this only work after the muffler? I have a single exhaust on my 350 and there really is no way of doing this after the muffler.

side note: not to go too far off topic will HFC's cause more drone?

08-04-2010, 07:13 PM	#46 (permalink)
Mike The370Z.com Sponsor Join Date: Jun 2009 Location: Loganville, GA Posts: 5,944 Drives: 370z Rep Power: 2186	Wish I knew about this when I had b&b bullets on my C6. Wife would plug her ears with her fingers for the week I had it. Plus rep! __________________ NISSAN: 75 280Z / 86 300ZX GLL /87 Sentra SE / 03 350Z / 23 Z Porsche: 93 968 / 23 Macan GTS / 93 968

08-10-2010, 09:14 AM	#49 (permalink)
'10Anamoly Track Member Join Date: May 2010 Location: GA Posts: 882 Drives: 2010 370Z BS M6 Rep Power: 16	Since the FI setup is the same pretty much as mine and the drone in is the same range, I would use 28-30" pipes, one per side. Any shorter and it will tune out drone above 3000rpms where you dont have the problem. Regular steel is fine but I would use some hi-temp paint to keep it from rusting ever. __________________ 2013 Ford Mustang GT 374rwhp, 360rwtq SAE / GT500 Axle-Backs / Brembo Pack / Track Pack / Recaros / 6spd

08-10-2010, 09:26 AM	#50 (permalink)
docaam A True Z Fanatic Join Date: Nov 2009 Location: Dubai Posts: 2,532 Drives: Z34/240z/Hakosuka Rep Power: 29	Thanks will plan the operation then how do you measure like someone would need 28" or 30" or less? __________________ Old 370Z SOLD but not forgotten 370Z 40th, G37s, S30 RBZ, Hakosuka Skyline

08-10-2010, 10:19 AM	#51 (permalink)
'10Anamoly Track Member Join Date: May 2010 Location: GA Posts: 882 Drives: 2010 370Z BS M6 Rep Power: 16	Speed of sound (typically 1100ft/sec, divided by the frequency at which drone occurs, divided by four because you want it to reflect at 1/4 the drone wavelength to cancel it out). So for drone around 110hz-112hz (around my setup), you get to 2.5 to 2.4 ft, or 29-30". __________________ 2013 Ford Mustang GT 374rwhp, 360rwtq SAE / GT500 Axle-Backs / Brembo Pack / Track Pack / Recaros / 6spd

10-05-2010, 02:02 AM	#59 (permalink)
docaam A True Z Fanatic Join Date: Nov 2009 Location: Dubai Posts: 2,532 Drives: Z34/240z/Hakosuka Rep Power: 29	Running FI exhausts for few months now, I can say the exhaust sounds awesome but what OP was referring to was not the normal drone (I can live with that) but vibration because of it. I do face that if I accelerate the car slowly(normal crusing) not pushing it hard as rpms has to go steady from 2k to 3k and its there for good 500 - 700, mine starts from 2200 and lasts till 2800. This thread shouldn't be taken anything against FI as they are an awesome company with awesome product, its just people have their own preferences. My daughter(7yrs) hates this drone and avoid sitting in the car LOL. I went through doing a DYNAMAT sound proofing when upgrading the audio it has reduced this vibration (not talking about drone/sound/noise) but its still there and if Tony gives some input on this thread I am willing to do this DIY __________________ Old 370Z SOLD but not forgotten 370Z 40th, G37s, S30 RBZ, Hakosuka Skyline

10-04-2010, 02:00 PM	#52 (permalink)
J. Dub Base Member Join Date: Sep 2010 Location: In your Internets Posts: 118 Drives: 09 370z 7AT Rep Power: 15	So fast intentions CBE drones.... I had no idea. Glad I didn't buy it last week.

10-04-2010, 02:09 PM	#53 (permalink)
TeamARK Track Member Join Date: Jul 2009 Location: CHINO Posts: 957 Drives: Black 350z/370z Rep Power: 17	But this exhaust doesn't ARK PERFORMANCE INC : 370z TRUE DUAL Prototype Teaser w/ dB Test.

10-04-2010, 03:54 PM	#54 (permalink)
Huan'z Track Member Join Date: Apr 2010 Location: houston,texas Posts: 641 Drives: black 370z 7/AT. Rep Power: 16	We need to confirm with Tony of f.I and let's see what his advice. I believe Tony tried a Lot of things before he decided to make his cbe. So give him a shot and wait for his respond. That's just only my own idea.

10-04-2010, 06:30 PM	#56 (permalink)
Huan'z Track Member Join Date: Apr 2010 Location: houston,texas Posts: 641 Drives: black 370z 7/AT. Rep Power: 16	with thedreamer. And take a look how many sets Tony sell out. I'm one of his customer still waiting for his cbe. And didn't hear anything like drone or whatever negative from other forum member. So let's wait from thedreamer. Hey bro keep us updated. Whenever u got yours and installed. Let me know so I can meet up with u. I want to hear from it and see how's good is it.

11-04-2010, 09:39 PM	#60 (permalink)
hr350z Base Member Join Date: Nov 2010 Location: CT Posts: 1 Drives: 07 350z MT touring Rep Power: 15	Will this only work after the muffler? I have a single exhaust on my 350 and there really is no way of doing this after the muffler. side note: not to go too far off topic will HFC's cause more drone?

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