1) Two of my mods are causing me problems. A while back i added an Eibach sport-line sway-bar and spring kit. since the day i drove it home i noticed rear end noise that sounded like a loose shock clacking. I looked under the car couldn't find anything loose. I decided to deal with it for the time being because the car handled great around corners. After a while i got tired of the harsh ride the sport-lines , so i decided to switch them out for the softer Eibach pro kit, hoping that the noise i was hearing would disappear. I Picked the car up after the install and sure enough the noise was still present... I decided to take a look at the steeda adjustable pan-hard bar thinking it may be loose and i found that my installer never centered the rear end. So i centered it and locked it down and some of the noise was no longer there but a majority of it was still there. I decided to see if i could hear the noise while the car was moving with the door open and i couldn't hear the sound outside the car at all. I decided that the noise was reverberating to the inside of the car cabin. The location sounds like its coming from the top of the spring isolators.. Its mostly present at low speeds over small bumps. Does any one know what this could be? could it be the higher spring rate pressure has destroyed my rubber isolators? should i replace them? I was thinking about getting duplicate isolators made of urethane material... They would have to be fabricated since no one makes them for the 2010 gt.

sounds like this:

http://www.youtube.com/watch?v=oeYc9owpBIY

Second issue totally separate from the 1st issue.

2) Now that I've added boom tube axelbacks, (love the sound), but the rear panels seem to be rattling under the deep sound pressure and i have i new screech sound that fades in and out. It only sounds off when the car is warm and moving, usually after 20 minutes of driving.. its not present when the car is cold.

So in closing the rear end of my car sounds like a change box, the front end is perfect, i would appreciate any insight on how i can solve this problem...

 

Hey Man, Im glad to hear you love your boomtubes also, but I also have the same problem with the interior panels rattling or vibrating anyone got any suggetions for me and Dominant?

 

Update: I decided to look at my Eibach sportline springs which i still have in the box. I noticed the very top of the spring second rung down on the under side of the spring, there is evidence of compression contact with the next rung down... no where else on the spring does it show any evidence of contact with other rungs.. and in that area there was no insolation wrapped around that point of contact. This tells me that upon compression of the spring that rung is making contact with the lower rung thus making noise. At higher speeds when the spring remains leveler, contact is less likely, and the sound is non existent. The stock spring rungs are to far apart from each other to ever make contact thus they never make the sound.. If i can find an nice urethane or rubber isolator that wraps around that spring at that contact point i can eliminate that noise....I will call Eibach tomorrow to see if they make such an item...

 

here is what i found:

http://www.phase2motortrend.com/esspnore.html

 

Those look like a good way to go! Did you ever find out which panels are vibrating from the boomtubes?

 

Update: I have a set of "QA1" 12 way adjustable shocks on the rear, and they were set on the softest setting, meaning the least amount of dampening. Today i adjusted them to a 4 setting to increase the dampening so it would help the upper spring rung resist hitting the 1 below it and now the noise is down to a minimum. I mean i barely hear it now. I figure when i get those noise dampeners to wrap around the contact points it will be gone...... problem solved....

 

Yeah a guy on the other forum helped me get rid of that metal screeching sound i was getting. He had the same problem. The drivers side hanger closest to the rear axle hits the hanger mount because the bend is close to it. when the car is cold the clearance is fine but when thing heats up it hits the mount thus causing a metal type screeching sound. So i went out and bought some high heat rubber hose and wrapped the hanger where it was making contact with the hanger mount and i secured it with a hose clamp problem solved...... damn i'm good....lol

 

Lol thanks man I'm going to get under mine and look at it! Sounds like a good idea Thanks!