Yup - WIFE IS LOUD!!! (exhaust acoustics) - ZR-1 Net Registry Forums

Schrade · 05-29-2014

Jeff was right - THis thing is LOUD!

Outside sounds great. I let a neighbor do a lap around the block after he helped lock down clamps. Sounded great driving off; I couldn't hear it on the back side of the block.

Inside is a different story. What I'm not diggin' so much is drone. It's loud between about 1,200 RPM's, to about 1,800, give or take. Gotta' be way below 40 Hz...

So I'm thinkin' on a few things here, individually, or in combination, to 'interfere' with the harmonic resonance:

1) Pipe wrap the 2 sections where the resonator was, and the X-pipe.

2) New (or additional) sound material under the carpet interior. I stayed with the original material because it 'smelled' new when I uncovered it for Black conversion.

3) Fitting / welding in a free flowing resonator behind the X-pipe (or 2 individual units, space permitting)

Where's Jeff T here; Jeff - did you consider option 3 here? Seems it would be an easy task, if a resonator could be modded for 2 x 3" inlets / outlets...

Of course, option 'b' would work too - turn up the radio

What did you do to take the edge off of interior noise, without hampering exhaust flow?

05-29-2014	#1
Schrade Join Date: Dec 2012 Location: NC Posts: 1,786	Yup - WIFE IS LOUD!!! (exhaust acoustics) Jeff was right - THis thing is LOUD! Outside sounds great. I let a neighbor do a lap around the block after he helped lock down clamps. Sounded great driving off; I couldn't hear it on the back side of the block. Inside is a different story. What I'm not diggin' so much is drone. It's loud between about 1,200 RPM's, to about 1,800, give or take. Gotta' be way below 40 Hz... So I'm thinkin' on a few things here, individually, or in combination, to 'interfere' with the harmonic resonance: 1) Pipe wrap the 2 sections where the resonator was, and the X-pipe. 2) New (or additional) sound material under the carpet interior. I stayed with the original material because it 'smelled' new when I uncovered it for Black conversion. 3) Fitting / welding in a free flowing resonator behind the X-pipe (or 2 individual units, space permitting) Where's Jeff T here; Jeff - did you consider option 3 here? Seems it would be an easy task, if a resonator could be modded for 2 x 3" inlets / outlets... Of course, option 'b' would work too - turn up the radio What did you do to take the edge off of interior noise, without hampering exhaust flow? __________________ I'm getting my snappics / threads removed blindly as fast as I can, to get in compliance with copyright / license TOS on the boards here (lots of FSM pages and other copyright / license violations on my part; sorry guys). And thanks to all the guys who didn't whine when I posted those FSM copyrighted / licensed stuff in my threads... ( :thumbsup: [b]and to think I complied with a mod's request to delete a pic of him in a Challenge Car in NCM Museum, so he wouldn't get in hot water)[/b] Thanks to several guys here for sending parts FREE; BearlyFlying, WeGone, Geezer, GoldCylon, and more there, TonyD, mike100, fletchusmc... 1990 #2794; 4L60e Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless, Power Effects 3" [IMG]https://lh5.googleusercontent.com/-GHpfzty7DVU/UQn-0Ru2xAI/AAAAAAAAA14/08mz1p4QLD4/s445/Screenshot-5.png[/IMG]