Exhaust Drone! - Page 12 - CorvetteForum - Chevrolet Corvette Forum Discussion

Notices
C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Exhaust Drone!

Old 01-15-2018, 05:36 PM
  #221  
95BLKVette
CF Senior Member
 
95BLKVette's Avatar
 
Member Since: Nov 1999
Location: Yorktown Heights NY
Posts: 1,447
Thanked 2 Times in 2 Posts
Default

Originally Posted by GREGGPENN View Post
I misquoted him. His article describes a 100ft cube of air weighing 38 tons vs the 100cu/ft I posted. That's (100x100x100x.0765)/2000...which does equal 38.25 tons.

It's kind of mind-boggling....to me.
Nope, 100 cu ft = 100 x 1ft x1ft x1ft = 100 ft3, whereas 100x 100 x100 = 1,000,000 ft3 (1 million ft3)
95BLKVette is offline  
Old 01-15-2018, 05:38 PM
  #222  
ddahlgren
CF Senior Member
 
ddahlgren's Avatar
 
Member Since: Dec 2008
Location: Mystic CT
Posts: 2,747
Thanked 57 Times in 55 Posts
Default

Originally Posted by GREGGPENN View Post
gain?

In terms of power, true....no perceivable gain.

In terms of sound, you'd probably like it better.
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?
ddahlgren is offline  
Old 01-15-2018, 05:46 PM
  #223  
GREGGPENN
CF Senior Member
 
GREGGPENN's Avatar
 
Member Since: Nov 2003
Location: Overland Park Kansas
Posts: 11,280
Thanked 115 Times in 110 Posts
Default

Originally Posted by MatthewMiller View Post
...it's completely possible to use cats that cause very little or no detriment to power.


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
GREGGPENN is offline  
Old 01-15-2018, 11:16 PM
  #224  
ddahlgren
CF Senior Member
 
ddahlgren's Avatar
 
Member Since: Dec 2008
Location: Mystic CT
Posts: 2,747
Thanked 57 Times in 55 Posts
Default

Did you remove the main cat?
ddahlgren is offline  
Old 01-15-2018, 11:50 PM
  #225  
GREGGPENN
CF Senior Member
 
GREGGPENN's Avatar
 
Member Since: Nov 2003
Location: Overland Park Kansas
Posts: 11,280
Thanked 115 Times in 110 Posts
Default

Originally Posted by ddahlgren View Post
Did you remove the main cat?
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.
GREGGPENN is offline  


Thread Tools
Search this Thread
Quick Reply: Exhaust Drone!


Sponsored Ads
Vendor Directory

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2018 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: