2015 5.0 Muffler Swap and Complications...

[TexityTex]

Recently I had the mufflers on my 2015 5.0 Ultimate swapped out for two offset single entry, dual out, Magnaflow mufflers, (I'm afraid I don't know the part number). The car sounds absolutely amazing when throttled. It was a hilarious ride home to have the luxury of an S-Class with Mustang-owners turning their heads at the sound.

As I said, the car sounded great.
Until... it warms up a bit. After about 10 minutes on the road, the standard Hyundai/Magnaflow drone kicks in. Normally it's not a big deal, but when your car comes only in an Automatic Transmission, and there are no shortage of low gradient hills on the way to work, a 20 minute commute is about 50% annoying.

I've been researching this problem for roughly two days now. I'm afraid I have no choice but to go back to the muffler guys and discuss the problem with them.

Before I do, I want to be well equipped to wax intellectual about the problem. So I'm looking for anyone, who's had similar problems. Is there anyone who has modified the exhaust on their 5.0 Tau V8? Anyone found a cure for the droning problem? Anyone who can give direct advice as to the core cause of drone other than the text-book "pipe resonance frequency" answer, as that means very little to a lay-person such as myself.

I've seen people suggest a side-chamber resonator on a T-Pipe. I've heard suggestions to delete the second Cat. I've heard that I should consider necking down the pipe size. I've even been told (and tried) that I can sound deaden the trunk to make it less noticeable. That did not work.

 

[NSXNEXT]

Swap Maganflows for Dynomax VTs. The internal flap helps minimize/eliminate drone at cruising speed.

 

[dmitriylm]

Outside of the Dynomax VT's (which I'm running on my 4.6) pretty much all mufflers will produce drone. This isn't an issue with the car but a general issue with aftermarket mufflers and low rpm / low throttle operation. It's more noticeable with V8's as they have enough low end to spend a lot of time under 2k rpm which is where you get a lot of drone. I've had many cars over the years (N/A i4, Turbo i4, I6, V6, V8) and have had some sort of exhaust on all of them (ranging from mufflers to cat deletes to straight pipes). They all had drone with any muffler loud enough to be noticeable.

 

[iRick]

It's just something you need to expect with adding loudness to any car.

This may be a silly question but does the 2015 come with the "manual mode" option? If so I suggest you do that. Ever since installing my straight pipe I am almost always in manual mode. This way you can choose the appropriate gear to avoid drone.

 

[Huddleston]

cutouts fellas..... loud and obnoxious and then flip the switch and she goes back to being nice a quiet.

 

[dmitriylm]

cutouts fellas..... loud and obnoxious and then flip the switch and she goes back to being nice a quiet.

Cutouts are a nice solution and I had a set on my Genesis Coupe but honestly I find that I prefer an aggressive exhaust that's tolerable all of the time rather than a super loud one that is tolerable some of the time. I'd much rather use cutouts to make my exhaust even more aggressive for those limited occasions but still have some nice tone/volume when they are closed. With a quiet exhaust in place and cutouts I found myself rolling with the cutouts closed the vast majority of the time and not enjoying the aggressive exhaust sound. Dynomax VT's function like dynamic cutouts where the butter fly valve only opens under specific throttle conditions but they aren't as loud as a set of traditional cutouts.

 

[RN2X]

I'm old school. 12" glass packs straight off of headers from a big block. But I am older now and enjoy the quiet ride

 

[scottdk]

I have improved the drone on MagnaFlow system by replacing the OEM H pipe with a MagnaFlow X-pipe muffler. This reduced unwanted exhaust frequency a lot, and I really like the exhaust now.

http://www.magnaflow.com/products?partNumber=11386&searchTerm=11386

 

[TexityTex]

Thanks folks, I appreciate all the feedback a great deal.

I've had a few days since posting this originally and after diving into sound engineering head on, I've learned a great deal.

I failed to add that the drone itself doesn't really bother me, it's just something I'm very conscious of when I have passengers. Surprisingly I've discovered that it doesn't bother the passengers all that much. Fortunately the drone is right above cruising RPM so it only rears it's head on slight throttle like a low gradient hill, or if I'm preparing to pass someone.

I have since done a lot of reading and studying of the 2015 exhaust line and I believe I've helped plan a solution that should reduce significantly if not eliminate the "piercing" drone.

So here's what I've learned...
The drone is between the 1600 and 2200 RPM range. The resonance is hitting at 120-136 khz.
The 2015 Genesis has true dual exhaust, in that, each header has it's own exhaust line. Header -> Cat -> Pipe -> Short Cat -> H-Resonator -> Muffler -> Facade Tips
The exhaust guys I've talked to have said that replacing the H-Resonator with individual resonators per pipe, could very well do the trick. I thought instead of putting on individual resonators, an X-Pipe might be the way to go. Fortunately my company has a team of engineers, so I presented the problem, and my possible solution, to them. They agreed that an X-Pipe does indeed sound like a good way of eliminating a large portion of the drone, or at least the most piercing levels of it.

Whether or not I will act on this, I have not yet decided... I fall more and more in love with the sound the car makes every time I drive it. It's a lot of fun seeing the faces of other tuners I know around the town who do not yet associate me with this new car.

Your input has been very useful and I thank you all for taking time to read my ramblings.

dmitriylm - I have not yet ruled out the Dynomax VTs either... I just really like the sound I have.

iRick - Yes it does have a "Manual Mode" and coming from a Genesis Coupe 3.8 Track A/T it's a much nicer "Manual Mode" than I had previously. A button has been added that allows me to "hold" a gear indefinitely.

Huddleston - I looked long and hard at electric cutouts, but in the end decided against it. I have no regrets about the direction I chose, but i do wish I had the option to shut down the noise on long trips.

 

[lbpuppy]

Is there any video of this. Would love to hear the sound of this.

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[suggi]

Is there any video of this. Would love to hear the sound of this.

Yes, please.

 

[bkpatel]

Thanks folks, I appreciate all the feedback a great deal.

I've had a few days since posting this originally and after diving into sound engineering head on, I've learned a great deal.

I failed to add that the drone itself doesn't really bother me, it's just something I'm very conscious of when I have passengers. Surprisingly I've discovered that it doesn't bother the passengers all that much. Fortunately the drone is right above cruising RPM so it only rears it's head on slight throttle like a low gradient hill, or if I'm preparing to pass someone.

I have since done a lot of reading and studying of the 2015 exhaust line and I believe I've helped plan a solution that should reduce significantly if not eliminate the "piercing" drone.

So here's what I've learned...
The drone is between the 1600 and 2200 RPM range. The resonance is hitting at 120-136 khz.
The 2015 Genesis has true dual exhaust, in that, each header has it's own exhaust line. Header -> Cat -> Pipe -> Short Cat -> H-Resonator -> Muffler -> Facade Tips
The exhaust guys I've talked to have said that replacing the H-Resonator with individual resonators per pipe, could very well do the trick. I thought instead of putting on individual resonators, an X-Pipe might be the way to go. Fortunately my company has a team of engineers, so I presented the problem, and my possible solution, to them. They agreed that an X-Pipe does indeed sound like a good way of eliminating a large portion of the drone, or at least the most piercing levels of it.

Whether or not I will act on this, I have not yet decided... I fall more and more in love with the sound the car makes every time I drive it. It's a lot of fun seeing the faces of other tuners I know around the town who do not yet associate me with this new car.

Your input has been very useful and I thank you all for taking time to read my ramblings.

dmitriylm - I have not yet ruled out the Dynomax VTs either... I just really like the sound I have.

iRick - Yes it does have a "Manual Mode" and coming from a Genesis Coupe 3.8 Track A/T it's a much nicer "Manual Mode" than I had previously. A button has been added that allows me to "hold" a gear indefinitely.

Huddleston - I looked long and hard at electric cutouts, but in the end decided against it. I have no regrets about the direction I chose, but i do wish I had the option to shut down the noise on long trips.

Lets say I don't give a damn about the drone. What would y'all think the best way to just let air into the restrictive system is? I have taken out the mufflers and after about a month the computer learned and my car is much more responsive than it used to be. My tires brake loose on the stock 19's. I talked to a Hyundai tech who's manager "turned his back" and he said that the only thing you can really do to our cars for now is unrestrict the exhaust system and just get the ecu reset.

 

[Huddleston]

Cutouts are a nice solution and I had a set on my Genesis Coupe but honestly I find that I prefer an aggressive exhaust that's tolerable all of the time rather than a super loud one that is tolerable some of the time. I'd much rather use cutouts to make my exhaust even more aggressive for those limited occasions but still have some nice tone/volume when they are closed. With a quiet exhaust in place and cutouts I found myself rolling with the cutouts closed the vast majority of the time and not enjoying the aggressive exhaust sound. Dynomax VT's function like dynamic cutouts where the butter fly valve only opens under specific throttle conditions but they aren't as loud as a set of traditional cutouts.

I understand that. benefits to each for sure.

 

[WHYTE5OH]

Anyone know the part# for the dynomax vt's that fit the 5.0?

 

[WHYTE5OH]

anybody? lol

 

[Joe29365]

Anyone know if this guy is still selling these cutouts? What's nice about them is that they are fully adjustable not just fully closed or 100% open. Also, anyone have any experience with using the 2nd cat delete pipes? Any benefit with just the stock exhaust?
http://youtu.be/y2a0vjHyUCE
http://youtu.be/DCNahOUdMXU

 

[tmf2004]

it really is the best of both worlds... I've seen that above video many times even before i wanted to be a Genesis owner... Its hard to believe just rear mufflers can produce so much drone that its unbearable (OP).. a full cat back yes but rear section not really IMO... I would like a little more rumble on throttle but nothing crazy... there has to be a part number for just the mufflers that are on the full Magnaflow cat back.. we should just be able to but the mufflers. I guess any 2.25 mufffler with dual exits will work

 

[celltech]

Based on Magnaflow's description the mufflers are 4x9x14, straight thru design. Although their kit pipes are 2.5" I assume you could create the same with a #11215 (satin) or #14315 (Polished) for 2.25". Looks like they made custom Y tips on the muffler output.

I would still be scared that it drones like crazy. I might even cough up the dough for their complete system if I knew it would not buzz me out of the cab. They don't call it MagnaDrone for nothing ;-)

 

[tmf2004]

Based on Magnaflow's description the mufflers are 4x9x14, straight thru design. Although their kit pipes are 2.5" I assume you could create the same with a #11215 (satin) or #14315 (Polished) for 2.25". Looks like they made custom Y tips on the muffler output.

I would still be scared that it drones like crazy. I might even cough up the dough for their complete system if I knew it would not buzz me out of the cab. They don't call it MagnaDrone for nothing ;-)

I wasn't sure our pipe diameter was 2.25 or 2.5??

 

[LarryJM]

FWIW the typical drone is in fact the harmonic resonance of the exhaust system because of the straight thru muffler not breaking up the exhaust note which is basically the engine firing frequency which in turn produces "exhaust pulses" in the exhaust system. The more free flow causes the tailpipe section from the muffler to the exhaust point to "resonant" at a frequency directly related to the tailpipe length. While, cutouts, side resonators, etc. can mitigate the effect the only "true" solutions are to go back and install a muffler with good baffles which "mixes up" this repetitive exhaust note so its not a consistrant frequency) or change the length of the tailpipe so the drone falls at an engine note frequency which is not one that you stay at, but typically just pass thru like when accelerating.

Larry