Original exhaust system?

[RogerN]

Does anyone know how to tell what type (chambered vs. transverse, etc.) of exhaust system came on this car originally from the factory? VIN 124379N566465. I think I am going to have to replace it.

It currently has a chambered system on it but I doubt it is the original one.

Any suggestions on whether to go with aluminized or stainless or which vendor to use?

[william]

That VIN was final-assembled a few weeks after the first NC8 recall so it is unlikely it had chambered.

Z/28s received an interim system consisting of the '68 deep-tone muffler w/o resonators. For the most part, big-blocks used the standard N10 resonator/muffler system. A few are known to have used the interim Z/28 system. Around mid-April '69, Z/28s were built with the standard N10 system.

What you buy depends on how you use the car. Chambered is noisy and more restrictive than other systems. Gets annoying if you use the car regularly. I know of well-preserved cars in the sun belt with original exhaust. Doubt stainless is worth the extra cost.

Gardner is the standard of excellence for restorations. I installed one years ago; very well-made and packaged. But cost is around 2x other systems. Consider it a show car system.

If you drive the car regularly, I would put standard exhaust on it. I have known these guys forever:

https://www.drclassic.com/catalog/Camaro

FWIW, no replacement system is made to duplicate assembly-line exhaust.

[uscrichter]

William, Did I read that right that the chambered exhaust is more restrictive and if so what was the purpose VS. standard dual exhaust?

[william]

The only reason could have been exhaust note.

Back in the ZL1 days, we helped Bill Porterfield with a ZL1 dyno project. The engine was tested in various states of tune, from as-installed with chambered exhaust [375 hp] to headers, carb and ignition mods [444 hp]. With open headers, 523 hp. Just pulling off the chambered exhaust picked up 79 hp.

A ZL1 is an extreme example. No matter, chambered is not a 'performance' exhaust system. The short-lived 1970 Pontiac VOE system did produce power gains.

http://www.camaros.org/copo.shtml

[RogerN]

So for the sake of keeping the car as original as possible, the interim system that was basically the '68 style deep-tone system (single transverse muffler without resonators correct?) would be most appropriate?

The N10 system is what you are referring to as the standard exhaust system?

Are there any performance differences between the interim system and the N10 system?

The exhaust pipe size is 2" or 2 1/4"?

[william]

Yes, interim system would be appropriate for your car. N10 is the production muffler/resonator system; 2.25" pipes. No idea on performance difference.

[69Z28-RS]

William, Did I read that right that the chambered exhaust is more restrictive and if so what was the purpose VS. standard dual exhaust?

JohnZ told several of us once that when engineering tested both systems (std vs chambered) the chambered system reduced power by 7 hp.  Engineering recommended using the std system only, but *marketing* over ruled them believing that the SOUND of the chambered would help sell cars.

[william]

Sound IS a big deal. Today, what you hear in the car is often dubbed in.

Best sounding '60s muscle cars were '68-'69 Mopar 383/440.

[69Z28-RS]

The chambered system uses the 'same' muffling pipes as the mid-year Corvettes side pipes, but there's more total length of pipe in the non-corvette versions, and also the length of the 'muffling pipe' is longer.  I think that 'straight pipe' sound is the attraction of the chambered system... I love the sound myself, but after talking to John and finding out that it costs 7 hp, and learning that my car was produced 'too late' for the chambered system to have been installed at the factory, I sold the NOS chambered system I'd bought in the mid-70's (after having them for 35 yrs!)..

[firstgenaddict]

The original systems used a welded rear muffler tail pipe assembly AND also had LAMINATED or what looks like double walled pipe on the head pipes as well and over axle pipes, which is what makes the systems sound less "tinny" than the reproduction systems.

[x66 714]

Here's a picture of the LH & RH tail pipe where they attach to the muffler. The RH was slipped into the muffler & welded. The LH was slipped over the muffler & clamped...Joe