billschroeder5842

This is just a question of curiosity.....

Does the later model single outlet ZR1 muffler have the same "guts" as a dual (yes, with the "fake" outlet") early style muffler? Or, are the internals different leading to a difference in performance or sound.

I wish that the '91 muffler was a true dual as I like the symmetry between the tail light and the muffler tips.

Clearly I have too much time on my hands.

ccmano

Basically the 90-92 systems are more restrictive and constructed slightly differently than the 93-95 systems. The 96 LT4 system is the best.

Haibeck does a great job explaining...
http://www.zr1specialist.com/HAT%20W...%20Systems.pdf

H

billschroeder5842

Thanks- I'm familiar with the article, which seems to place a lot of the restriction on the resonator. I swapped my restrictive OEM for a MF "X" pipe a while back.

My question is on the mufflers them selves; are there any difference between the early and late one for flow and sound?

ccmano

Frankly, you will not notice a SOTP between the two, even if it’s a hp or 2. No difference in sound. You made the right move with the resonator. It’s really only a question of look and sound. If you want that to change you need an aftermarket muffler. If you want more performance you need headers.
H

ZR1Bob

All of the stock mufflers are a bit restrictive as they each contain a Helmholtz resonator sized to eliminate the well known drone at a specific rppm. A Helmholtz resonator is essentially a closed chamber with an entrance for sound waves to enter and bounce around, kind of like a coffee can with a pipe stuck into one end. Its size and shape determine what frequency waves will cancel each other out. As a result, the path for the exhaust to enter and exit the muffler is a bit convoluted. As noted above, Marc H has a good explanation of the restrictions on his website. The muffler is the most restrictive part of the exhaust system, at least in the later years because the center resonator was improved and is much less restrictive than the early ones. This is why I put cutouts in front of the mufflers on the '95. When open we probably gained about 15-20 HP. --Bob

ccmano

That’s actually a great idea, best of both worlds.
H

Rkreigh

take a 93-95 system, add x pipe, and update muffs

you have a poor mans b&b that will support lots of HP and sound great

I like the b&B flapper system or to retrofit a c6 tip onto the magnaflow muffs

I have a b&B 3" but the factory 2 3/4 is pretty good once your swap out the resonator with x pipe and update muffs