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: 3,245
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 
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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.
