hey guys. No flaming... I just spent the past two hours reading about this. I just installed a set of ultimate racing high flow cats on my car. I got these because I had heard bad things about the kinetix rattling and the crawfords cracking and I read a good review on these. Anyway the gains are cool and for the most part so is the sound. But I'm getting a metalic type buzz from 3-4k under WOT. I have read extensively about this from test pipes and random tech and crawford cats but not with ultimate racing cats. Also there was never a real solution given in any of the threads. I doesn't seem like a sound that you would describe as RASP but more like a metalic buzz and it usually does it more when its cold and the car hasn't warmed up fully. Any input would be greatly appreciated.

 

bump d bump

 

bump diddly

 

Please update. Have you found and eliminated the buzz? Since your posting this I assume you haven't. Have you bent the heat shield? I was just ready to order these cats when you first posted about the buzz, so now I'm holding off tiill I hear more. Thanks, Ernie-Seattle

 

Don't take this the wrong way, I'm not trying to flame or be a jerk but, to find the answer to these kind of problems you really need to spend more time looking under your car and less at your computer monitor. It's more than likely a heat shield.

 

I should be getting the car up on the jack stands tomorrow to see about the het shield. someone else suggested that it might be the bracket. So we'll see. I was gonna get it up on there this weekend but I went to the Richard petty driving experience this weekend at charlotte motor speedway.

 

Wow man how was that? I'd love to go some day. Did you meet Kyle or The King? Kyle's my favorite driver and he seems to be a great man.

Gary

 

awesome

 

didn't get to meet either of the pettys though

 

Aside from the buzz, how does it sound? Did the HFC's make your Stillen TD a lot louder? What about pitch...higher or lower or the same?

 

other than that it sounds great. louder, deeper and meaner.

 

yo... I just got 2 new UR HFC's in the mail today out of the blue. Anyone have any ideas why they sent them to me? think they saw this thread and wanted to make things right?

 

No clue, but I'll buy them from you..

 

sounds like a vibrating heat shield as stated above. it might just be loose, or slightly touching your exhaust causing the sound from high vibrations.

 

Your rattling sound sounds like some metal-on-metal vibrating, i experienced the same with my exhaust - one of the hangers was touching metal and i would hear it exactly when you hear it on your Z. Check out that heat shield and any other metal to metal contact.

 

hole E smokes, that's what I call service! You still have the bzzzzz noise?

 

only when the car is cold so i just wait till it warms up to get on it and no buzz. eventually i'll probably take it to somewhere with a lift and try to either readjust it or bend the heat shield back. In the mean time those two new ones are up for sale if anyone is interested