N11 (off road) Muffler Drone/Resonance

[Brant H.]

Does anyone have any experience with any possible drone or resonance at speed with the N11 Off Road Exhaust from Corvette Central or Gardner?

Honestly, I would not expect any, but I want to make sure.

Most clips and comments only mention the sound when idling or perhaps upon acceleration.

The car in question is a stock built '63 FI car, but I would be interested in feedback from owners running the exhaust with any engine.

Thank you.

[Keith B.]

Re: N11 (off road) Muffler Drone/Resonance

my dad has the CC N11 system in a 65 L76 with 4:11 rear. and there is no noticeable drone while driving

[Dan H.]

Re: N11 (off road) Muffler Drone/Resonance

I have Gardner system, smooth when driving, a nice 'bark' in between gears when getting frisky, car is a 64 FI.
Dan

[Harry S.]

Re: N11 (off road) Muffler Drone/Resonance

I have a Gardner setup on my 300 hp 63. I don't know if you would call it a drone, but there is a distinct noise there. I have a non-N11 setup on my 250 hp 63 and it is very quiet.

[Bob I.]

[Mark E.]

Re: N11 (off road) Muffler Drone/Resonance

Interesting. CC standard exhaust is on my '70. Fitment is great (see my separate thread) but it's so loud I contacted CC, wondering if they sent an N11 by mistake. Nope, the standard exhaust is N11 loud. Little cruise speed drone, but a vibrant thrum at idle, and there's little doubt I'm coming while accelerating. Definitely not a stock sound, and a bit loud for my taste.

[Bob I.]

IMG_1074.jpg

[Mark E.]

Re: N11 (off road) Muffler Drone/Resonance

Have you reached out to CC? They may correct the issue or even take it back altogether.

[Mark E.]

Re: N11 (off road) Muffler Drone/Resonance

Have you reached out to CC? They may correct the issue or even take it back altogether.

Another thought: It may be faster and easier for a local shop tweak the pipes to fit as you want. It shouldn't take much.

[Bob I.]

Re: N11 (off road) Muffler Drone/Resonance

Have you reached out to CC? They may correct the issue or even take it back altogether.

[Mark F.]

Re: N11 (off road) Muffler Drone/Resonance

Bob,

Just a thought if you're not wed to the N11 system...or need it for flight judging...

After taking my car thru flight judging 2000 to 2003 with my "original ?" N11 system, I didn't want it rusting up any more than it already had so I purchased a chambered exhaust system from Allen's (2003 @ Carlisle). I think they may be out of business now ?

Anyhow, installation was a dream; pipes lay in there nicely and come out the valance perfectly aligned; no rattles; no drones + a really nice , low rumble

Don't know who sells chambered exhausts these days...and it may not matter as that might not be what you're looking for...

[Brant H.]

Re: N11 (off road) Muffler Drone/Resonance

Thank you for all of the replies. I just wanted to make sure that I would not experience the resonance that some Flowmaster mufflers are bad for.

[Brant H.]

Re: N11 (off road) Muffler Drone/Resonance

Bob,

Just a thought if you're not wed to the N11 system...or need it for flight judging...

After taking my car thru flight judging 2000 to 2003 with my "original ?" N11 system, I didn't want it rusting up any more than it already had so I purchased a chambered exhaust system from Allen's (2003 @ Carlisle). I think they may be out of business now ?

Anyhow, installation was a dream; pipes lay in there nicely and come out the valance perfectly aligned; no rattles; no drones + a really nice , low rumble

Don't know who sells chambered exhausts these days...and it may not matter as that might not be what you're looking for...

Thank you for the suggestion. While I'm not particularly interested in judging anymore, I at least want that original look with the mufflers.

The chambered systems are certainly cool though.