Annoying NVH ?

[krhonn]

Hey everyone, I have this horrible "echo" sound around 45mph and above. This noise never occurred before these mods.
Upper control arm and bracket (polly adj)
Lower control arms (polly nonadj)
Adj panhard bar
1.5" lowering springs on all 4 corners
RXT clutch
Sound goes away once clutch pedal is pushed in.
Any ideas, anyone?

 

[imeyers302]

As soon as i installed my steeda upper control arm and mount i got a lot more "echo" / whining from thw rear end. I have 3.73s which dont help either. I really dont care about the added noise though.

 

[sono]

My understanding with the clutch is it works or slips. Had both scenarios.
2 types of dynomat. Thin light stuff that sticks to the trunk floor and under the rear seat. Also a thick peace to lay on top under the carpet in the trunk.
Results are big improvement in random rodent like noises.

 

[krhonn]

I don't take long rides in the car but if i happen to get on the interstate for 30 minutes or so it really gets to the ears.
Thanks for the responses so far.

 

[Reaper14]

I made all them upgrades on mine minus the clutch & nothing like that happened. Narrow it down to maybe something with the clutch?

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[krhonn]

I was thinking the same considering when the clutch pedal is pressed it stops. But I wonder what could be causing the clutch to do so if that's what it is?


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[geoffmt]

twin disks make noise. if it goes away when pushed in, you found the noise. it isn't anything wrong with it, just chatter. you can and will get a little more noise with rod ends and stiff bushings in control arms, they just don't dampen vibrations like soft stock rubber. If you want to hide those new noises from performance parts, may I suggest the Borla attack mufflers or an American thunder setup from flowmaster

 

[chris_302]

I have the same problem, it's the UCA, make sure the pinion angle is properly set. Swap back to stock UCA so you can compare.

 

[Mojo88]

I have the same problem, it's the UCA, make sure the pinion angle is properly set. Swap back to stock UCA so you can compare.

I have basically same rear setup as OP, with Roush UCA and Steeda LCA's, and I'm getting plenty of NVH. Plus my car is lowered (from Roush). Do I actually need both upper and lowers with poly bushings? Did the lowering mess up my pinion angle? Do you have any link you can give me (and the OP) showing how to check/set pinion angle on these cars?

Thanks

 

[imeyers302]

If you change the control arms, especially the upper from stock to even a poly bushing you are going to get more noise transmitted into the cabin. Its as simple as that. The harder the bushings the more NVH you will hear. 3.73 gears or higher even moreso. The roush is supposed to be a little more compliant of an upper as opposed to steeda, etc... but will still transmit more noise than stock. Spherical bearings will make it even worse.