I just finished my true dual install, dumped before the rear axle. I used moroso spiral flow mufflers. I got everything tucked real well, but I have a terrible vibration at idle and around 2500 rpm. I mounted them just like this pic, http://www.lt1engine.com/media/album_page.php?pic_id=13 I used the same style hangers and mounted them into the seat belt holes. Does anyone have any idea about what would be a better hanger location? Also, I removed the hangers and started it and the vibration was gone.

 

Did you add turndowns after that picture was added? With just the Borla XR1 mufflers, I had a horrible resonance that would vibrate everything in the interior, at similar RPM. My mufflers were bolted directly to the collectors. Adding enough pipe after the mufflers to get the exhaust to the end of the rear floor pan (probably about where the one in the picture ends), and adding 3" turndowns eliminated the problem. It wasn't a vibration transmitted through the hangers, because I didn't have hangers. It was a resonance problem.

 

Do you still have the stock tunnel brace? If so it might be hitting there...

 

No, i dont have turn downs. I will add some pipe and put some turn downs on it. Thanks for the idea!

If your talking about the thing that looks like a cheap driveshaft loop, its been out 4 over a year.

 

I added dumps, and they are dumping right in front of the rear axle. The vibrations stayed about the same. How does everyone hang their duals? I used the seat belt holes.

 

mine vibrate like hell, but that's because the pacesetters hit the frame on the driver side....

 

Anybody else got any ideas?

 

got access to a drive on lift? if you do pull it up, leave it running and try to narrow it down to the area its coming from, could probably put on some gloves and feel around for the vibration too

 

scott did the same thing same mufflers same exhaust mounted to the same holes and has the same problem...pm me if youve already fixed it...

 

Here is how mine is, no resonance here.