Flowmaster 40 Series muffler..????
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Flowmaster 40 Series muffler..????
Have Flowmaster mufflers, part number 42441 which is the 40 Series with 2.25" in/out. They were on the car when I got it.
Everytime I take the rear exhaust section off for some reason, I dump rust parts out of them. I finally got feed-up and took them off today and gots lots of rust parts out of them. They were quiet...nothing like the Magnaflows I have on my 96 LT4.....Is this normal for the 40 Series or or mine just plugged-up with rust?
Got to get new mufflers.
And no I cannot get side pipes due to emissions....same for headers...at least not until Arizona passes the 25 year old car - no emissions required law....keeping my fingers crossed.
But until then.....guess I will go with the Magnaflows from Corvette Central...is this the best price for bolt ons?
Thanks in advance,
LannyL81
Everytime I take the rear exhaust section off for some reason, I dump rust parts out of them. I finally got feed-up and took them off today and gots lots of rust parts out of them. They were quiet...nothing like the Magnaflows I have on my 96 LT4.....Is this normal for the 40 Series or or mine just plugged-up with rust?
Got to get new mufflers.
And no I cannot get side pipes due to emissions....same for headers...at least not until Arizona passes the 25 year old car - no emissions required law....keeping my fingers crossed.
But until then.....guess I will go with the Magnaflows from Corvette Central...is this the best price for bolt ons?
Thanks in advance,
LannyL81
Instructor
Joined: May 2006
Posts: 175
Likes: 0
well 2.25 isn't a very big diameter and if there not mandrel bent the restriction will be down to 2 inches. As far as the rust issue goes that doesn't sound good at all. Id replace the whole exhaust with 2.5 inch mandrel bent exhaust with an H-pipe and flowmaster 40s it should be loud then
Melting Slicks
Joined: Aug 2004
Posts: 2,165
Likes: 950
From: Keizer Oregon
I've got 2.5" flowmaster 40's....Definitely no rust thang.......that just doesn't sound right.......2.25" is pretty restrictive for a decent 350............And 40 series are anything but quiet, you must have them really plugged up.
Racer
Joined: Aug 2005
Posts: 435
Likes: 2
From: Boise Idaho
Originally Posted by oregonsharkman
I've got 2.5" flowmaster 40's....Definitely no rust thang.......that just doesn't sound right.......2.25" is pretty restrictive for a decent 350............And 40 series are anything but quiet, you must have them really plugged up.
I have those Flowmaster 40's as well. They have a great rumble to them.
They came with my car and are around 4 or 5 years old.
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
No the tips were not turned up catching rain water.....besides...it never seems to rain here in Tucson anymore...
All I can say is that a little bit of shaking and I get a rattle. Dump out more rusted guts. Just when I think I have it all out....out comes another piece.
But I would think that the muffler would get louder with all the baffles falling out....tempted to put them back on and see if they flow any better. I tried pushing a wire into both inlet and outlet...only went a short ways in. Do not know what what these Flowmasters look like on the inside as far as chambers and such.
Probably just order a new set of Magnaflows from CC and be done with it.
LannyL81
All I can say is that a little bit of shaking and I get a rattle. Dump out more rusted guts. Just when I think I have it all out....out comes another piece.
But I would think that the muffler would get louder with all the baffles falling out....tempted to put them back on and see if they flow any better. I tried pushing a wire into both inlet and outlet...only went a short ways in. Do not know what what these Flowmasters look like on the inside as far as chambers and such.
Probably just order a new set of Magnaflows from CC and be done with it.
LannyL81
Melting Slicks
Joined: Jan 2004
Posts: 3,247
Likes: 210
From: Detroit MI
I had a Flowmaster 40 series rust through from the inside after about five or six years. My car doesn't see enough rain for that to cause it, I assume it was caused by condensation in muffler after the engine was shut off.
Le Mans Master
Joined: Oct 2004
Posts: 5,269
Likes: 54
From: Orlando Florida
St. Jude Donor '05
I just took a Flowmaster 80 series muffler off my DD. The muffler looks still fine after 4 years and roughly 60000 miles. I had about 2lbs of rust chunks on the floor when I took it off 
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Melting Slicks
Joined: Jan 2005
Posts: 3,028
Likes: 0
From: Madison Ms
Hmmmm...not to alarm you, but something doesn't sound right. Rusting of very old mufflers is quite common, but new mufflers would have to be exposed to a fair amount of moisture/condensation to rust out like that. How's your engine running? You sure you are not blowing water out the exhaust in a fine spray? Cracked block or heads could be your problem, or a problem you can't identify as of yet.......
Race Director
Joined: Feb 2005
Posts: 16,100
Likes: 17
They were on the vette when he got it..no telling how old they are...
LannyL81:
Get new mufflers...you won't get all that rust out of those things..and your cat is probably gone too...get a 3" high flow cat...
LannyL81:
Get new mufflers...you won't get all that rust out of those things..and your cat is probably gone too...get a 3" high flow cat...
Last edited by rihwoods; Jun 5, 2006 at 12:03 PM.
