What are these for and should I transfer them to the new mufflers?

thanks

 

Don't remember mine having those They're in the attic so I could confirm later. I do know that they weren't used on any aftermarket exhaust that I've seen.

 

Not sure what they are, maybe dampers to keep it from rubbing against the underside of the car, but you don't need them on your new system.

 

From my understanding they are for drone, noise, harmonic balance. there are 4 of them, there are other by the y pipe. My stillen exhaust had it in the instructions to transfer them over (only because they had made the appropriate mounting for them). Im not sure if other aftermarket exhausts have the same mounting points (Top Speed and Tanabe didnt).

 

OP, those are vibration dampers. "Muffler bumpers", LOL. Hold one in your hand, and they're surprisingly heavy, solid rubber.

Here's a little story: right after I had my RHF cats installed at the beginning of the year, there was a new and very noticeable vibration at idle. Pretty annoying vibration, too, just sitting there with the clutch depressed; although soon as I gave it some throttle, it went away. Someone on the forum suggested I remove the vibration dampers in the mid-pipe, since I had changed the exhaust configuration with these cats. I did, and the vibration faded to almost nothing. Kind of ironic, removing something designed to absorb chatter in order to eliminate chatter.

 

I have the same issue! I WILL be trying this now. Thanks for the insight.

 

Surprised that it's as noticeable with the idle speed of your 7AT, but if this works for you, very happy to have helped. If it's as much a silver bullet as it was for me, this "fix" really should become more common knowledge here.

Then again, most people install cat-backs before replacing their cats, and not the other way around like I'm doing. Oh... looking at your sig, and I see your Tanabe exhaust is axle-back. Hmm. Good luck, Warped.

 

BTW, replaced stock with Tanabe axle back and it still sounds stock. These are used in very good condition. Will be adding Berk HFC next weekend.

Fwiw I drove around the block without mufflers and it sounded pretty awesome. Pure raw motor (catted and resonated of course).

 

While replacing the hub plastic centric rings with aluminum rings I took off the dampeners. So far it seems to have worked. The real test will be early in the morning when it's still relatively cool out (that's when the idle vibration is most noticeable). The engine idle speed I thought was no different between transmissions. 675 or so? My idle was bumped up with my tune to 750 RPM. I don't know why but the tuner told me he had done it.

 

For whatever reason, I was under the perception that the 7AT had a higher idle.

Well then, GTK. Thanks.

I also went for aluminum rings over the plastic. I bet it doesn't matter a wit, except a little peace of mind. Not sure why that either, but I'm using them.