Rattling/groaning after new exhaust install

[tylerk]

Since I installed my N1 downpipe and exhaust, I've noticed a deep groaning/rattling coming from under the car only when I accelerate quickly from a stop. As soon as I get going, or if I get going smoothly, it doesn't happen. It sort of sounds like the exhaust is rattling against the underbody of the car. Does anyone have any suggestions? Any more info I can provide?

 

[river]

loose bolts or couplings? check and make sure for clearance on everything. also, under hard accel in a turbo car it may sound like it is rattling or something a bit. i dont know how to explain that sound but many will probly know what im talking about. all i can suggest though is to look for loose bolts/nuts and make sure you have clearance with your oil filter and that its not vibrating and hitting something under your car. good luck

 

[EclipseTrbo420A]

Is it a "home made system" or brand name ? also how many of the hangers did you use ? there a bunch or shields above the whole system so it doesnt heat up the underside of your car and if the exhaust isnt to secure then it will hit of off those..

 

[tylerk]

The whole system is Apexi N1. I didn't miss any hangers as far as I can tell, and I removed the heat shields. I'm betting I just didn't tighten some of the bolts enough. I'm going to have a look at it tomorrow, I will update if I find the solution.

 

[tylerk]

I only had a little time to look at it, so I just did a quick inspection of the back half (where it sounds like the noise is coming from). The one thing that I did notice is that part of the exhaust is right up against one of the brackets that holds up one of the brake lines. I can see where this would cause a LITTLE noise, but I can't see how it's causing noise as loud as I'm hearing. All the nuts/bolts seem to be tight and secure. All the exhaust hangers are safe and secure.