Aftermarket Exhaust. Vibrations in cabin 800 - 1300RPM

[Matt77]

HI Guys,

I've had a custom exhaust fitted locally including secondary cat deletes and yes it does drone a little which I can live with but I'm also getting a vibration which can be felt through the console at around 800 - 1300 RPM. I took the axle back section off and refitted the factory mufflers and it was gone so I'm assuming that we are just hitting the resonant frequency of the floorpan or something. Does anyone else have this with aftermarket (not Kia Bi-modal) systems?

So far tried the following and would say there has been a mild improvement:
- Double checked all hangers, mounts etc.
- Dynamat Boot area
- Removing brace near transmission
- Harmonic Vibration Dampers

Anything else I'm missing?

 

[Stinger GT SS]

Is your custom exhaust a name brand or fabricated by a Muffler Shop?
Another forum colleague @Ozstung just posted on the Ark Grip thread that he was experiencing similar issues with his install.

 

[Matt77]

Is your custom exhaust a name brand or fabricated by a Muffler Shop?
Another forum colleague @Ozstung just posted on the Ark Grip thread that he was experiencing similar issues with his install.

Mine is custom fabricated by a local exhaust shop. Overall it's actually pretty quiet as it has large rear mufflers and twin 4.5 in resonators in the mid section. I was close to getting the Ark but it was more expensive even without the downpipes and there were supply issues at the time.

 

[Stinger GT SS]

Ok, maybe go back to the muffler shop & discuss your issues, you may have some trial & error to eliminate your vibration, but if your muffler guy knows his craft he should be able to resolve this issue for you, keep us posted with its progress.

 

[Bryan3.3]

HI Guys,

I've had a custom exhaust fitted locally including secondary cat deletes and yes it does drone a little which I can live with but I'm also getting a vibration which can be felt through the console at around 800 - 1300 RPM. I took the axle back section off and refitted the factory mufflers and it was gone so I'm assuming that we are just hitting the resonant frequency of the floorpan or something. Does anyone else have this with aftermarket (not Kia Bi-modal) systems?

So far tried the following and would say there has been a mild improvement:
- Double checked all hangers, mounts etc.
- Dynamat Boot area
- Removing brace near transmission
- Harmonic Vibration Dampers

Anything else I'm missing?

I’m have a custom set up as well and I am also experiencing creaking noises from the plastics on the console. I’ve grabbed some of the parts on the center console while it’s doing it. I found on mine on the right side where the top of it turns down to the passenger side is where it’s making noise. I plan on placing some felt between the two plastic pieces so they do not rub against each other.

 

[Matt77]

Ok, maybe go back to the muffler shop & discuss your issues, you may have some trial & error to eliminate your vibration, but if your muffler guy knows his craft he should be able to resolve this issue for you, keep us posted with its progress.

Yeah he is working with me but we don't seem to be having a lot of luck at this stage. I may have to get home to fab up some Helholtz resonators tuned to the frequency if we can't resolve it.

 

[Matt77]

I’m have a custom set up as well and I am also experiencing creaking noises from the plastics on the console. I’ve grabbed some of the parts on the center console while it’s doing it. I found on mine on the right side where the top of it turns down to the passenger side is where it’s making noise. I plan on placing some felt between the two plastic pieces so they do not rub against each other.

I don't have creaking as such just feel the vibration when my arm is on the center armrest.

 

[Stinger GT SS]

Yeah he is working with me but we don't seem to be having a lot of luck at this stage. I may have to get home to fab up some Helholtz resonators tuned to the frequency if we can't resolve it.

Good luck, I’m sure there will be something or someone out there that can resolve this for you.
On a positive note if you resolve it with the result your looking for you maybe able to market/patent it with your muffler guy & make some $$$$.....

 

[Ozstung]

I don't have creaking as such just feel the vibration when my arm is on the center armrest.

Identical to the issue I'm having. But perhaps it will settle down as mine mysteriously did today. I've heard the mufflers need time to "Carbon up". My drone starts at 1500 revs through to 2000. Outside that range it's perfect. If it continues I'm going the damplifier pro route.