Exhaust Drone!
#221
Drifting
Nope, 100 cu ft = 100 x 1ft x1ft x1ft = 100 ft3, whereas 100x 100 x100 = 1,000,000 ft3 (1 million ft3)
#222
Melting Slicks
The gain for me would be the loss of drone. It begs the question of does the stock engine make less power with stock muffles compred to a Borla or similar cat back system?
#223
Race Director
By design, they wouldn't want to compromise efficiency because it would defeat the reason to use converters. They flow straight through. Lower density cell units have less restriction. In general, you have 100, 200, and 400 cell units.
100 are random cats.
200 are performance
400 are stock
I'm not sure "factory" cats restrict much even at their level but people building for power need/want to look at everything. My opinion is a converter has always been the best muffler too -- because of the added "cleaning" benefit.
I have had a converter go bad (burn up) after short usage so I understand the reason to avoid them. That said, I've run Metallic Magnaflow bullets for 7yrs w/o issue (off my header collectors). The ceramic "main" cat I tried lasted only 3 months in the belly. That shows the much higher level of durability of metal vs ceramic. Metal can take the higher heat off the headers where ceramic couldn't even survive downstream.
Plus, I think the "main cat" size/shape was detrimental to sound quality due to the larger case. I've run an '89 stocker with no fronts but with a main. Sound drone was nuts. When I put front cats back in it, it was fine...even without much muffler. I'm currently running a much higher powered 383 with front cats and no main cat. That setup is fine. (Side pipes have resonator mufflers)
FWIW, This was the best sounding setup I had on my STOCK 350. Magnaflow cats (lower-priced ceramic...but with shielding), Allen stainless Y pipe, custom polished targas with resonators welded in the bends. Cheesy heat shields installed the day AFTER the shop had throw the OEM unit away. LOL
FWIW...I started w/o the front cats and w/o the resonators. I added the resonator in an attempt to kill drone. Putting front cats in solved the problem. This was all 2.5" piping vs the stock 2.25" on L98s.
I had forgotten the front cats were in non-symmetrical locations. Aren't LT1's non-symmetrical? Maybe that helps too? By "tuning" each side slightly different.
Last edited by GREGGPENN; 01-15-2018 at 06:24 PM. Reason: added the word stock AND...the FWIW addendum
#225
Race Director
On my 383 yes. Not on the stock setup shown above.
I'm surprised it's so tame but my 383 has headers, metallic front cats dumping into a sidepipe system equipped with a resonator. That's it. Sometimes wish it were louder!
front view of 383 BEFORE removing center muffler:
I really does sound better without the center BOX muffler.
I'm surprised it's so tame but my 383 has headers, metallic front cats dumping into a sidepipe system equipped with a resonator. That's it. Sometimes wish it were louder!
front view of 383 BEFORE removing center muffler:
I really does sound better without the center BOX muffler.