JohnZ

If that's the N-11 repro they've been selling for the last couple of years, they don't sound ANYTHING like the originals; the originals had a pleasing deep, mellow sound with no raspyness (is that a word?) or resonance.

Tim Gilmore

John, yes, it is a wonderful sound. It's a tough decision to install them because when they're gone, they're gone. I try not to worry about it on my '65 and just enjoy. I think that original side pipe systems are better sounding than the reproduction systems, also.

Chambered

OK, I know what exhaust you are talking about now. The internals on the OE would be a staggered 2-tube design - flow rate was not one of the attributes of this type of muffler. This type of muffler design, combined with the length of them, would be easy to eliminate (or reduce) excessive resonance. They could be built either with or without packing to absorb sound. The trick to higher flow rate would involve larger diameter flow tubes internally, as well as a design that would be conducive to getting the exhaust to exit the muffler more easily. What were the dimensions of the OE mufflers (length & cross section)? Also, what were the inlet & outlet diameters?

I can probably get blueprints of the OE offroad design.

JohnZ

Don't know the dimensions offhand, but all midyear mufflers (except base-engine Powerglides) had 2-1/2" inlets and 2" outlets.

The N-11 muffler assemblies (which included the exhaust pipe from the trans crossmember back) were 3845735 LH and 3845736 RH.

GCD1962

I'm sure the off the roads are nice, but to pay a high price for an original set-up and install it on the car seems like a waste as the cheap steel they are made from would start to deteriorate very quickly and in a few years it would be "gone"

Ironcross

Off-road exhaust is merely bragging rights now on an original invoice. These cars are pressing 40 or more years since construction. I`m going to tell you what muffler to use if you really want a throw back sound. The Walker fiberglass {Hollywood style} round straight muffler will get you where you want to be. Not really actively promoted since the introduction of Walkers Dynomax products. But these sound the same as my original off-road system.

Chambered

I built these today: 40" long, 3" body dia., 2.25" neck & core, & special perf pattern in the flow tube. OE was under a 2" flowpath.

(Anybody want to put the pic. up for me - I don't know how to attach the photo?)

B&BVettes

That's about right I have the NOS N-11 on my BB, real nice sound.

noelga

e-mail me the picture I will put it up for you.

gonefishn

If you could get the blueprints of the OE offroad muffler that would the the target design. They had a unique sound as described by a few of us in previous threads. Duplicating this, via the same design, would be highly desirable by many (as seen by the number of viewers and contributors to this post).

Is this something feasible?

John

2toys

When someone is able to duplicate the shell dimensions and get close to the original sound, I'm ready to buy.

I don't want "also fit" mufflers.

Chambered

Let me just say that Walker may have been OE on these. I may find something out tomorrow - I'll let you know.

Ironcross

Arvin was the major OEM supplier during that period including the Corvette chambered exhaust systems. We handled Arvin then as a distributor.

gonefishn

ttt
Chambered?

oWen recently shared new additional information.

http://forums.corvetteforum.com/show....php?t=1516432

Seemed like there was plan or investigation underway within this thread. Would be worth while to manufacture IMO.

John

wmf62

repeating my initial comment.... if you want to know how they're built inside without tearing one up, take it to a materials testing company that can do radiography and talk to them about xraying it.
Bill