I was wondering if anyone has added resonators to quiet down their aftermarket exhaust systems. I've had my FI exhaust and Berks HFC for close to a year now, though it's quiet enough for me on the outside, the inside of the car has incessant vibrating issues because of it. It's louder when I have the windows closed than when i have them open. Any ideas? I've read a little about someone adding the resonator modules from the XYZ test pipes to another aftermarket system, but I wouldn't know how that works.

 

Get rid of the HFCs. Problem solved.

 

how about i don't and say i did? Let me add I want to keep the cats if possible.

 

Let's say you add resonators and it doesnt' fix your problem. Then what?

I went through a similar experience going catless on my WRX. I spent money on the test pipe. Then tried an intermediate pipe with resonator. Then tried lower flowing muffler that was said to be the quietest. In the end, I could not tame the noise and went back to catted midpipe. Problem solved. I did not even miss the slight performance gain because the tradeoff was my car didn't sound like a POS anymore!

 

Well in my case the sound is close to what i want. The cabin noise is ridiculous though. The whole car vibrates and resonates at low RPM and it's unbearable at exactly 55mph. Honestly, if it comes down to it, i'll put the stock cats back. However, if I can avoid it (because the outside sound is what I want), I'd not like to replace them.

 

I hear you. I wonder if those weights on the stock exhaust can be clamped to the FI like they do on the Stillen. They can't be there for nothing. In any case, good luck. I just would hate to see you hack up your FI for something that may not work.

 

Oh. Didn't realize I'd have to hack up the exhaust. Damn. Hmm, I guess I'll try sound dampening the whole car. Already did the trunk and back seat. The floor would probably help the most.

 

A resonator is an exhaust piece unless you are talking about something else. But I think your problem is that there is resonance of the exhaust system at a certain speed. What I was getting at about the stock weights was changing the resonance. I wish I could find something like this to experiment with:


I noticed too on the highway cruising that some speeds will have fine seat vibrations. Sure it can be wheels/tires but I've noticed this with different setups. I have a Borla exhaust btw.