Ok, I tried to search but when you have "buzz" in the search field, all you get are damn "clutch buzz" threads.

Anyway. The exhaust has a nasty buzz upon cold start up. Once the car warms up, it goes away and sounds great. Anyone have an idea of what this could be and how to fix it? This buzz was presant before I chopped up the HKS so I know that isn't the problem.

Right now I'm running an Invidia TP + HKS. Stock header. Could it be a gasket that is shot somewhere on the exhaust?

 

Could be, when it warms up it expands?

 

That's what I was thinking but I couldn't hear any exhaust leaks up stream. the buzz comes from the mufflers. I do know the gasket between the TP and the cat-back was in pretty rough shape. I think Berk sells them. Maybe I'll try that.

 

Change your gasket and check to make sure everything is tight.

 

Are hks mufflers packed, or perforated metal? Could be a small break in the internal packing that just barely touches (causing vibration when cold) that heats up enough to make solid contact (no buzz).

 

To be perfectly honest, I don't know. That's a great point though. I'll have to look into it. But if that's the problem, I guess there really isn't anything I can do.

I'm going to try the gasket replacement next weekend. I'll report back if it helped. Thanks guys

 

and I think the HKS muffler are perf'd metal IIRC.

Hey, it only happens when the exhaust is cold, right?

 

That is correct, only when it's cold. She warms up quick but it's annoying still.

Freq, when I drove away from you at KOP, did it buzz then? The car was obviously still warm from the drive up but I'm wondering if that short amount of time cooled the exhaust enough to cause the buzz again. It's not really important for diagnosing the problem, I'm just curious.

 

Don't remember having a buzz, I left that stuff at home.

Seriously though, we have almost identical exhausts and yours sounds AWESOME. I can only hope mine sounds as well as yours does.

 

Next time bring that sh!t

Well with the sound chamber off, I know it sounds a little different. Not much though. Maybe a little deeper. But the HKS does sound awesome! Do you have a test pipe as well? Also, what header are you running?