Flowmaster Original 40 Series Offset/Offset Oval Muffler - 2.5 in. (79-04 All, Excluding 99-04 Cobra)

Customer Reviews (40) Write a Review

Overall Rating 4.8

out of 5 stars

Installation Time:Full Day

Installation Cost:$100-$250

• Loudness / Volume 3.894737 3.9
• Exhaust Note 4.421052 4.4
• Fit & Finish 4.631579 4.6
• Bang For Your Buck 4.631579 4.6

• 5/5

  July 10, 2010

  Takes some time

  I had 44's on but nowhere near the same sound as the original flow 40 series...going through tunnell's is heaven and shifting at 2500 rpms is heaven sent lol they were a tad quiet at first but after 100 miles there starting to wake up!! dont get any but the original flows!!

  Co

  Helpful (38) Thanks for your input!
• 5/5

  April 05, 2010

  Classic 40s

  I had these welded in today they sound incredible I have the stock h pipe with cats and it is still nice n loud, it has a great deep tone and it was a great 1st mod for my car. 2200 RPM is the sweet spot.

  Dale P

  Helpful (24) Thanks for your input!
• 5/5

  February 25, 2010

  great mufflers

  I put on a pair of Flowmasters and what a difference they made in sound and horsepower. Getting these mufflers along with a cold air intake and your mustang will improve performance 100%. I recommend these mufflers to other mustang owners.

  Chris

  Helpful (22) Thanks for your input!
• 5/5

  August 27, 2010

  Great sound

  Installed Original 40 Flowmasters and am very please with the sound. The only problem I had was I had to adapt the flanges to my orginal equipment pipes. Be sure you know what size pipes you have before ordering.

  Bob

  Helpful (18) Thanks for your input!
• 5/5

  October 06, 2009

  nice

  Very nice product, Adds the nice deep throaty exhaust note

  C

  Helpful (10) Thanks for your input!
• 5/5

  March 05, 2010

  Great sound

  I have Original 40 series on my '01 V6 model and to my ears it is a great sound. People ask me a lot if it is the GT model, and one GT owner told me, "That sounds amazing for a V6!" It doesn't get too raspy like some other kits might. Overall a great choice.

  Daniel C

  Year: 2001 Submodel: V6

  Helpful (7) Thanks for your input!
• 5/5

  November 17, 2010

  Folwmaster 40

  sound great. one of the best mufflers ive had. Make my mustang sound like a gt. =]

  Michael Jaser

  Helpful (6) Thanks for your input!
• 5/5

  August 17, 2010

  97 v6 mustang

  i have 2.25 pipes to 2.5mufflers to 2.25 tips. it has no h or x pipe and it sounds good at low rpms get a little raspy at high rpms. i was worried at first but the sound is great with a bbk throttle body and k and n cai. i would recommend them to other v6 owners. the were also a great price and the shipping is free and fast

  jon

  Year: 1997 Submodel: V6

  Helpful (6) Thanks for your input!
• 5/5

  Installation Time: Shop Install

  October 10, 2011

  Sound Awesome

  Replaced old mufflers once they started to rust at the inlet pipe, these new mufflers sound amazing on my dual exhaust V6.

  SonicEvan

  Year: 2004 Submodel: V6 Lethbridge, AB, Canada

  Helpful (4) Thanks for your input!

  • Loudness (Volume) 4

    4

  • Exhaust Note 5

    5

  • Fit & Finish 5

    5

  • Bang for your Buck 5

    5
• 5/5

  November 05, 2010

  flowmasters on my 02 mustang

  I wanted a nice rumble with the windows down...and a quite with the windows up..... Perfect sound, so i read they break in after 100 miles.. alittle louder would be good also. Not damn on my auto v6 shipping as good, the faster the better.... Cheers american muscle -kriss-

  kriss daigle

  Year: 2002 Submodel: V6

  Helpful (3) Thanks for your input!
• 5/5

  January 21, 2010

  WOW

  HAD THIS PUT ON AND WOW WAY BETTER THEN SOUND LOVE IT I HAVE A 01 CONV WHIT h PIP VERY NICE SOUND LOVE IT @2000 RPM GREAT BUY

  ROBERT

  Year: 2001

  Helpful (3) Thanks for your input!
• 5/5

  Installation Time: Less than 1 Hour

  January 01, 2014

  Can't beat the classic note of these 40 series mufflers

  I bought these to replace a set of awful sounding mufflers the original owner of my cobra installed. I'm very happy with the classic note of these mufflers. I am very happy to see the quality of flowmaster remains the same it was back in the 90's! I also commend American Muscle for their customer service. There was a small issue over shipping but customer service was quick to communicate and solved the problem fairly and swiftly.

  Jeremy88

  Year: 1997 Submodel: Cobra Florida

  Helpful (2) Thanks for your input!

  • Loudness (Volume) 4

    4

  • Exhaust Note 5

    5

  • Fit & Finish 5

    5

  • Bang for your Buck 5

    5
• 5/5

  July 15, 2011

  the best

  had to order new mufflers and went with the original 40s and man do they sound great...love that original flowmaster sound!!!!

  ryan

  Year: 2004 Submodel: Mach 1

  Helpful (2) Thanks for your input!
• 5/5

  December 04, 2009

  great sound

  just got these installed on my 03 gt they sound awesome just need a x pipe now

  Tanner

  Year: 2003 Submodel: GT

  Helpful (2) Thanks for your input!
• 5/5

  July 25, 2016

  Flowmaster 40

  If you're like me who owns a v6, you are always looking for ways to look and sound like the big boys. Well, these plus Mac long tube headers = OMG. I've never thought that my little 3.8 could sound good. Deep rumble at idle and tons of neck breaking when driving down the road. I would recommend these two products for anyone who has a v6 and want the v8 burbly sound. Hands down the mid I've ever done to my car!

  Stabgfan99

  Year: 1999 Submodel: V6

  Helpful (1) Thanks for your input!
• 5/5

  Installation Time: Shop Install

  Installation Cost: $250-$500

  May 13, 2013

  go all out

  I have 40s on every muscle car I have and to make sure my 02 gt could compare with the sound of the 60's muscle since its legal where im at I completely changed the exhaust removed the cats and did straight pipe back with the 40's and even the tiny v8 in the new edge mustang can keep the sound of a big block

  borocamo

  Year: 2002 Submodel: GT Fruita, CO, USA

  Helpful (1) Thanks for your input!

  • Loudness (Volume) 5

    5

  • Exhaust Note 5

    5

  • Fit & Finish 5

    5

  • Bang for your Buck 5

    5
• 3/5

  Installation Time: Less than 1 Hour

  October 04, 2012

  Nice tone

  Sounds good. The inlet and outlet were a little bigger than the measurements on line said they would be, but it wasn't nothing a little extra welding couldn't fix.

  04terminator

  Year: 2001 Submodel: GT Hebron, IN 46341, USA

  Helpful (1) Thanks for your input!

  • Loudness (Volume) 3

    3

  • Exhaust Note 2

    2

  • Fit & Finish 2

    2

  • Bang for your Buck 2

    2
• 5/5

  July 10, 2011

  Flowmaster

  Make my car sound great. People think my v6 sounds like the GT. Thanks American muscle

  Jayce

  Year: 1999 Submodel: V6

  Helpful (1) Thanks for your input!
• 5/5

  February 26, 2011

  Nice sound and feel

  Awesome sound! Get's loud up to about 2500 rpms but gets quiet once you're on the open road in 5th gear. Make sure you know your pipe size. I had to have midas custom fabricate part of my stock H pipes to fit them. 2.5 inch pipes and 3 inch tips

  Ryan

  Year: 2004 Submodel: GT

  Helpful (1) Thanks for your input!
• 5/5

  November 19, 2010

  beats the ground

  I have a 93 notchback with 3 in 2 chambers and they are super loud they beat the ground!

  austin dukes

  Year: 1993

  Helpful (1) Thanks for your input!