When I bought my car it already had a Flowmaster Catback installed. I've always thought the mufflers were called 2 chamber flows but I've been listening to the sound clips on Mustang Exhaust.com and now I'm not sure. Maybe they are Super 40 Series?? I crawled under my car today and the only thing I noticed was the Pat number but that didn't help much. Can anyone tell me how to tell for certain what I have. I've used the search button with no answers so far. 
Different Flows
- Thread starter Dr Jay
- Start date
Dr Jay said:When I bought my car it already had a Flowmaster Catback installed. I've always thought the mufflers were called 2 chamber flows but I've been listening to the sound clips on Mustang Exhaust.com and now I'm not sure. Maybe they are Super 40 Series?? I crawled under my car today and the only thing I noticed was the Pat number but that didn't help much. Can anyone tell me how to tell for certain what I have. I've used the search button with no answers so far.
Super 40's are black, so that will be pretty obvious to you
If you post the part# we can tell you exactly what you have 
Jay
twogts4us
15 Year Member
To add to that, the American Thunder catback has the 2 chamber "42543" mufflers - it should be laser etched on one end of the mufflers...I believe it's on the rear.
JayC said:Super 40's are black, so that will be pretty obvious to you
Jay
Mine were grey colored but I'm pretty sure I have the super 40's. If that is in fact what I have, then I wish I had the originals...I thought thats what I would be getting.
stangman16
Active Member
Is there a major difference between the Super 40's and the original 40 series? I'm contemplating on getting some super 40's and an off-road H-pipe for a deep classic sound. Think this'll help achieve that goal?
Well I crawled under the stang and all I got besides a wet sleeve was US PAT 4574914. There is no numbers on the front or back of the muffler, just the stamping on the bottom with this number. Anyone know what type of Flowmaster I have here 
I'll try to post a pic
I'll try to post a pic
Dr Jay said:Well I crawled under the stang and all I got besides a wet sleeve was US PAT 4574914. There is no numbers on the front or back of the muffler, just the stamping on the bottom with this number. Anyone know what type of Flowmaster I have here
I'll try to post a pic
Time to get your other sleeve wet.....the number is stamped in the end of the muffler opposite the inlet or outlet...should be a 5 digit number like this....
http://img253.imageshack.us/my.php?image=img01006nw.jpg[
Jay
The number on my mufflers were etched onto the SIDE of the muffler where the outlet pipes are (its the flat area). A buddy of mine had the numbers etched right onto the outlet pipe itself.
It's very faint and not deep and it's pretty hard to see. I could imagine it being even worse when they're dirty..
It's very faint and not deep and it's pretty hard to see. I could imagine it being even worse when they're dirty..
dollarbill
Member
I just took some flows off my car a few weeks ago. I bought flo42543 2.5 inch 2 chamber mfflers. The description from Brother's says American Thunder Classic muffler. Hope this helps but before you buy flows please consider others. I've heard flows are the bottom of the pack for performance, and the drone drove me crazy.
dollarbill said:
I love the drone. I kinda wish i could get my Flows to drone even more. I purposely drive around at 2000RPM just to hear them hum.
Well trip number 3 under the car has turned up some new numbers. Man were these things ever hard to read. I swear I looked in that same spot before and missed them altogether.
I've got 942543-121 on the passenger muffler and 942543-120 on the drivers side. I just checked Flowmasters website and the catback system they sell now for our mustangs does not match these numbers. Can anyone tell me what I have
I've got 942543-121 on the passenger muffler and 942543-120 on the drivers side. I just checked Flowmasters website and the catback system they sell now for our mustangs does not match these numbers. Can anyone tell me what I have
JayC said:Putting that number along with the fact you have a Flowmaster catback , you have a pair of 2.5" original 2 chambered mufflers. Congrats they are the best sounding Flowmaster IMO
Jay
Thanks for the feedback JayC
Just the stock H for now. I was planning to go with a Catless H pipe or a Prochamber this summer but I can't decide which.
Both are pretty expensive but the sound is why I bought the car in the first place and I don't want to mess it up. Just like everyone else here I get complements all the time on the sound of my car, I just want it louder.
Mkes sure you hear a prochamber, catless H and X pipes before you make up your mind. I prefer the X on a 99+ car and the H on a 5.0...but that's just me 
