too much drone

[shadow191]

Not a "direct" bolt on, but close enough. The width between the inlet and outlets is the same as the Invidia X-pipe area. So the shop just cut off the little resonators and welded this in place, then extended the pipes a little since the original X-pipe is gone too. No other mods needed. This should give you an idea of how they did it. I had originally wanted to keep the Invidia resonators to suppress sound even more, but they wouldn't clear the W brace and neither would the Magnaflow.





---------- Post added at 08:03 AM ---------- Previous post was at 07:55 AM ----------

Adding a resonator isn't going to increase drone; an incorrect one or incorrectly placed one may not do much to decrease drone though. A resonator is a straight through muffler, it can't add noise.

And Dynamat does work, but not that well for exhaust noise. My entire car is Dynmatted, mostly because I thought I was going to put a big stereo in, but ended up not. It cut road and tire noise a ton. The exhaust noise was cut a little bit, but that's not really what Dynamat does. To cut exhaust noise, you'd have to use actual foam. Dynamat just keeps panels from vibrating and won't do much for the exhaust. The weight isn't that bad, I think all in there's ~50 lbs or so of Dynamat. The FX is already slow, that weight isn't going to make much difference. It does however make the car feel slightly more luxurious since the NVH is reduced.

Drone is the result of harmonic resonance in the muffler/resonator. This harmonic is amplified in the exhaust system and manifests itself in the cabin of the car. You can add a couple of straight through glass packs (resonators) to the exhaust. Adding the wrong size resonator or putting one in the wrong place will just as likely increase the drone as well.

And whatever you do, do not Dynamat the car. It will just muffle the sound, and add weight to the car.

 

[iDrive]

It looks real good with the resonated xpipe if I put it in the same spot as you it should reduce the drone then right because I don't want to put it in a spot where it won't do anything

 

[Exotich]

Not a "direct" bolt on, but close enough. The width between the inlet and outlets is the same as the Invidia X-pipe area. So the shop just cut off the little resonators and welded this in place, then extended the pipes a little since the original X-pipe is gone too. No other mods needed. This should give you an idea of how they did it. I had originally wanted to keep the Invidia resonators to suppress sound even more, but they wouldn't clear the W brace and neither would the Magnaflow.





---------- Post added at 08:03 AM ---------- Previous post was at 07:55 AM ----------

Adding a resonator isn't going to increase drone; an incorrect one or incorrectly placed one may not do much to decrease drone though. A resonator is a straight through muffler, it can't add noise.

And Dynamat does work, but not that well for exhaust noise. My entire car is Dynmatted, mostly because I thought I was going to put a big stereo in, but ended up not. It cut road and tire noise a ton. The exhaust noise was cut a little bit, but that's not really what Dynamat does. To cut exhaust noise, you'd have to use actual foam. Dynamat just keeps panels from vibrating and won't do much for the exhaust. The weight isn't that bad, I think all in there's ~50 lbs or so of Dynamat. The FX is already slow, that weight isn't going to make much difference. It does however make the car feel slightly more luxurious since the NVH is reduced.

Shadow, where did I say that adding a resonator is going to increase the drone?? Adding the wrong size resonator or putting it in the wrong place will increase drone. The solution, as I pointed out above, is to modify the harmonic source, or eliminate it all together. Think of the muffler as a speaker... as the vibration from the cavitation of exhaust gases is amplified down the exhaust stream, it will manifest as sound as it expands in the muffler/resonator. Exhausts are designed to do this; that's the secret of particular exhaust notes that we all love (harmonics). The ones we don't love just have a different resonance. By changing the muffler/resonator, you change the properties of the exhaust stream and have modified the sound... You have changed the exhaust's "speaker".

For Dynamat, I was relating it to exhaust drone noise, not road and tire noise to stay on topic. As far as helping with the Drone it all depends on the type of exhaust you have. Some exhausts do drone louder than others to begin with. Unless you pack layer on top of layer on top of layer, it does very little to block noise. A large piece of mass loaded vinyl on top of closed cell foam under that "false floor" panel in the back would help, but MSV is heavy and expensive to ship. By adding all that foam and Dynamat the weight is going to be much more than 50lbs. You add an exhaust to the car for performance. You don't then weigh the car down and add layers upon layers of dynamat or heavy ass MSV to help quiet the interior noise. And adding every little weight to the "already heavy FX", makes a huge difference performance wise.

 

[shadow191]

For the X-pipe, that's the only spot it will fit. And generally the further up you put it, the more effect it has.

It looks real good with the resonated xpipe if I put it in the same spot as you it should reduce the drone then right because I don't want to put it in a spot where it won't do anything

---------- Post added at 10:48 AM ---------- Previous post was at 10:34 AM ----------

You said adding one in the wrong spot or wrong size will increase drone. That's just not possible, it may be less effective than a properly placed one, but it's not going to increase drone. If you have an exhaust with no resonators, adding one will decrease volume no matter where you place it. If you have an exhaust with one resonator already, adding a second one will decrease volume. If you place them towards the end of the exhaust or use a tiny one it will have less impact, but there's no way it will increase drone or noise. Resonators are filled with sound suppression material, they're not reflecting sound back like some mufflers. The actual OEM muffler is chambered so it will reflect certain waves. But if OP is using an HKS knockoff, it's probably the straight through muffler.

To stay on topic, Dynamat does impact exhaust noise. Not as much as some people think, but it does have an impact. If you're on the edge of thinking your exhaust is too loud, it may make just enough difference. If you straight piped your FX, then it won't make enough difference. I didn't add my exhaust for performance, I could care less about the impressive 4hp I might get. I don't like the OEM exhaust tone so I changed it. I didn't Dynamat the car for the exhaust, but it was just an added benefit that it cut the noise a little. If that means I run 15.9 in the quarter vs. 15.8, I can live with that. I've done the whole weight reduction thing in previous cars and it's just not worth it. FX isn't fast so no point in compromising comfort for a miniscule amount of speed. I'd rather just enjoy it.

Shadow, where did I say that adding a resonator is going to increase the drone?? Adding the wrong size resonator or putting it in the wrong place will increase drone. The solution, as I pointed out above, is to modify the harmonic source, or eliminate it all together. Think of the muffler as a speaker... as the vibration from the cavitation of exhaust gases is amplified down the exhaust stream, it will manifest as sound as it expands in the muffler/resonator. Exhausts are designed to do this; that's the secret of particular exhaust notes that we all love (harmonics). The ones we don't love just have a different resonance. By changing the muffler/resonator, you change the properties of the exhaust stream and have modified the sound... You have changed the exhaust's "speaker".

For Dynamat, I was relating it to exhaust drone noise, not road and tire noise to stay on topic. As far as helping with the Drone it all depends on the type of exhaust you have. Some exhausts do drone louder than others to begin with. Unless you pack layer on top of layer on top of layer, it does very little to block noise. A large piece of mass loaded vinyl on top of closed cell foam under that "false floor" panel in the back would help, but MSV is heavy and expensive to ship. By adding all that foam and Dynamat the weight is going to be much more than 50lbs. You add an exhaust to the car for performance. You don't then weigh the car down and add layers upon layers of dynamat or heavy ass MSV to help quiet the interior noise. And adding every little weight to the "already heavy FX", makes a huge difference performance wise.

 

[iDrive]

So I went to the muffler shop today told me the resonated x pipe wont do anything. And told me to just put my oem back on and dont waste money because he said no matter what there will always be drone I dont know how true this is. Should I just put the oems back on?

 

[gto]

Get the tips extended out

 

[shadow191]

Yeah, at minimum have the tips extended because if they're exiting under your car, it will make the noise worse. Go to www.g35driver.com or my350z.com and search Magnaflow resonated X-pipe. They even have sound clips to show you how much it helps if you have the HKS replica or anything similar.

 

[iDrive]

Okay will do just really impatient haha and worried cuz I spent money on it and if I spend more and still not satisfied im gonna regret it

 

[jbaker1121]

Okay will do just really impatient haha and worried cuz I spent money on it and if I spend more and still not satisfied im gonna regret it

We've all been there. I've gone through 3 different exhaust setups on my FX50... haha

---------- Post added at 10:19 PM ---------- Previous post was at 10:18 PM ----------

So I went to the muffler shop today told me the resonated x pipe wont do anything. And told me to just put my oem back on and dont waste money because he said no matter what there will always be drone I dont know how true this is. Should I just put the oems back on?

This is wrong. If you add resonators / X pipe it alters the noise and will reduce drone.

 

[Logan]

Many of the standard exhaust shops employ welders not specialists, I would first suggest to find another shop, then extend your tips per GTOs suggestion, then run the resonated x OR a single 300 cell HFC on both pipes as close to the end of your cat connector as possible, the closer to the engine a resonator is installed the easier it is to kill the drone/resonance. BTW-tonal quality or the sound of your exhaust and harmonic resonance/vibration although related, are two different topics.

 

[mars]

i got the top speed pro axle back custom on .its got a lot of drom too

 

[iDrive]

just the axle back and you have drone? I put the whole exhaust with the y pipe too and I put the magnaflow resonated xpipe where the two resonators were and now it has little to no drone at all only certain rpms has drone but not on Highway.

 

[santiagodraco]

To stay on topic, Dynamat does impact exhaust noise. Not as much as some people think, but it does have an impact. If you're on the edge of thinking your exhaust is too loud, it may make just enough difference. If you straight piped your FX, then it won't make enough difference. I didn't add my exhaust for performance, I could care less about the impressive 4hp I might get. I don't like the OEM exhaust tone so I changed it. I didn't Dynamat the car for the exhaust, but it was just an added benefit that it cut the noise a little. If that means I run 15.9 in the quarter vs. 15.8, I can live with that. I've done the whole weight reduction thing in previous cars and it's just not worth it. FX isn't fast so no point in compromising comfort for a miniscule amount of speed. I'd rather just enjoy it.

Completely agree with this. Unless you are already reducing weight and totally focused on turning your FX into a race car then there's no reason to not sound deaden. It's a huge improvement if done right in the comfort of driving our cars. Mine is done front to back and it's the best mod I've done.

 

[jptshadow]

iDrive, so which rpm range reveals drone after you put the R-X Pipe on?
Currently, the non-mod Invidia drones at 2.1k to 2.4k range (which is usually cruising on 70mph)
And what part number for the Magnaflow R-X pipe? thanks

 

[jptshadow]

Just added this mod to the Invidia today and it DOES NOT DRONE anymore!! while still keeping the "vroom" sound.
Lovin' it!!!! :rotfl:

 

[iDrive]

iDrive, so which rpm range reveals drone after you put the R-X Pipe on?
Currently, the non-mod Invidia drones at 2.1k to 2.4k range (which is usually cruising on 70mph)
And what part number for the Magnaflow R-X pipe? thanks

Sorry never saw your post. The part number is 1456. The drone with the xpipe happens around when I drive 120km/hr? On the highway the city it does a bit but doesnt bother me but I do a lot of highway driving and driving me crazy these days! Without the xpipe sounded like a boat loud but had no infiniti tone in it

---------- Post added at 06:37 PM ---------- Previous post was at 06:35 PM ----------

Just added this mod to the Invidia today and it DOES NOT DRONE anymore!! while still keeping the "vroom" sound.
Lovin' it!!!! :rotfl:

Glad u got rid of the drone im getting the factory put back on cuz someone rearended and the muffler got pushed in and cracked

 

[Bklynjohn718]

So pretty much get rid of the invidia xpipe and put in a resonated muffler as shown in the previous pics?

Sent from my SAMSUNG-SM-N910A

 

[jptshadow]

Oh No!! That sucks, man. Wish u and the car quick recovery!

---------- Post added at 10:42 PM ---------- Previous post was at 10:40 PM ----------

So pretty much get rid of the invidia xpipe and put in a resonated muffler as shown in the previous pics?

Sent from my SAMSUNG-SM-N910A

Yes, Plus the Invidia resonators which were too small to do anything.