Name: Flowmaster Outlaw Axle-Back Exhaust (05-10 GT, GT500)
Brand: Flowmaster
SKU: 18423
Price: 455.95 USD
Availability: InStock
Rating: 4.9 (372 reviews)

Review & Install Video

Hey everyone I’m Justin with AmericanMuscle.com, and today we’re going to be breaking down the Outlaw series Axle-back from Flowmaster for the 2005-2010 Mustang GT. Flowmaster calls this their most aggressive Axle-back system available for the late model 46 Mustangs. This entire kit centers around these two outlaw series mufflers, which to the casual observer, hardly resemble mufflers at all, but rather highly engineered resonant tubes, which are responsible for that super aggressive tone. Like many other Flowmaster kits the Outlaw series features 409 grade steel construction and 2.5” mandrel bent tubing. It also features this very sleek black finish, which is going to be great at resisting corrosion. Everything exits out of these dual 4” polished tips, embossed with that classic Flowmaster logo. Installation of this Axle-back is very straight forward and should only take you about an hour using some basic hand tools. Now let’s hear how the Outlaw series from Flowmaster sounds compared to your factory exhaust.

What's in the Box

(2) Muffler assemblies
(2) Clamps

Installation Info

Installation Time

(approx) 1 Hour

Difficulty Level:

Light to Moderate mechanical skill required.

Installation Guides

Manufacturer:
How to install a Flowmaster Outlaw Series Axle-Back Exhaust on your 2005-2010 Mustang

Customer Submitted:
How to Install MAC Boom Tube Axle-Back Exhaust on your 2005-2010 GT and GT500

Tech Specs

Axle-Back Exhaust Specifications

Piping Material:	409 Stainless Steel	Tip Material :	Polished Stainless Steel
Piping Size:	2.5"	Tip Size:	4.0"
Muffler Type:	Straight-through	Fitment:	2005-2010 GT, Bullitt and Shelby GT500

Tech Guides:

Will it fit my Mustang?

Bullitt - 08, 09
GT - 05, 06, 07, 08, 09, 10
GT500 - 07, 08, 09, 10

Questions & Answers (59)

5 Top Rated Questions

SLPLOUNDMOUTH OR FLOWMASTER OUTLAWS DID HE HAVE A BIG DIFFERENCE BETTEWN THE SLP LOUNDMOUTH AND THE OUTLAW. THE FLOWMASTER OUTLAW IS IT REALLY LESS LOUND THAN SLP LOUNDMOUTH I HAVE A GT 2005, AND I REALLY DONT KNOW WITCH ONE BUY. WHICH ONE IS GONNA BE THE BEST FOR SOUND AND PERFORMANCE. WITCH PART I COULD JOIN TO THE OUTLAW FOR INCREASE SOUND AND PERFORMANCE THANKS

Outlaw is plenty loud all by itself. If you want to amp it up try some long tube headers paired with an h pipe. But trust me they're good all by themselves
all muffler deletes are loud, hence no muffler. the Outlaw is quieter than other deletes on cold start ups and they roar at WOT
outlaws for sure. youll be happy. they have a different, own style sound, unlike any I have heard but are impressive even at high rpm's. sound dont disappear as you step on the gas, very little drone at all.sounds NASTY
I purchased the outlaws, I had stock mufflers before. They are loud and sound amazing and I picked up from 14.07 to a 13.81

Helpful (9) Show 3 more answers

How do these sound on a V6 with true dual? Do you have a sound clip available?? I removed the X brand because of cabin drone... will these create a drone on the V6? Thanks

I have sound clips of a 2009 V6 with the ford racing dual exhaust that uses a true dual setup and the same mufflers as the bullett mustang, and the Flowmaster Outlaw. The Outlaw provides a much deeper throat tone to the exhaust making it more like a V8 sound. It has a little bit of drone at certain RPM's however it really gives the V6 a muscle car sound. The closest thing I can relate it to is the new Boss 302 Laguna Seca. IT SOUNDS AWESOME!!!!
http://www.youtube.com/watch?v=eVne5HYVIqw&feature=youtu.be Hopefully that link works. The video is called "2009 Mustang V6 dual exhaust sound clips"
very slite drone,unlike the classic's but sound NASTY. I mean NASTY. totally different sound I have heard. youll love em

Helpful (5) Show 2 more answers

Im looking for exhaust to fit a 2010 mustang that sounds like a Lamborghini, any ideas? This one sounded like it may have that same rumble/sound.

These would be two completely different motors and would no exhaust for a 2010 Mustang will sound like a Lamborghini.

Helpful (3)

Do the Flowmaster Outlaw series Axle-Back Exhaust add horse power to your Mustang.

That is a big yes and they sound real good and meaty.
No they do not add horse power to your car, just changes the sound.
Over stock? Yes. Anytime you install more free-flowing muffler, you will unlock more horsepower.

Helpful (2) Show 2 more answers

Borla s type or flowmaster outlaw, which one have deeper sound?

The flowmaster outlaw will have a more aggressive and deeper exhaust tone.

Helpful (1)

10 More Questions

I have a 2005 Shelby GT500...will these work? 1 answer

This Flowmaster Outlaw Series Axle-Back Exhaust will not fit a 2005 Mustang GT500.

Helpful (1)

Will the Flowmaster Outlaw Exhaust pass Pennsylvania state inspection? 1 answer

The Flowmaster Outlaw Series Axle-Back Exhaust will be legal in all states for inspection.

Helpful (1)

I have the Pypes muffler deletes on my 05. Are these Flowmaster Outlaw axle back louder and have a deeper sound than the Pypes muffler delete's? Cant really hear the difference between the video's 1 answer

The Pypes Muffler-Delete Axle-Back Exhaust (05-10 GT, GT500), item # 20022, (http://www.americanmuscle.com/pypes-2005-gt-muffler-delete-axel-back.html) may have a slightly higher pitched sound than the Flowmaster Outlaw Series Axle-Back Exhaust, The Flowmaster's are going to have a very deep sound that is also loud. It also depends on what other exhaust mods you have made. Different headers and mid pipe will drastically change the sound of the car as well.

Helpful (1)

I currently have muffler deletes on my 09 gt but want something different but similar loudness would this be what I’m looking for ? 1 answer

The flowmaster outlaws will offer a very aggressive exhaust tone that will be comparable to muffler deletes.

Helpful (0)

how would these sound paired with an X pipe? 1 answer

It would honestly depend on the x-pipe, but the Flowmaster Outlaws will generally offer a loud and aggressive exhaust tone.

Helpful (0)

im assuming you dont need a tune for this??? 1 answer

Axle-back exhausts generally will not require a tune.

Helpful (0)

I’m looking to upgrade to long tube headers on my cammed 2009 gt. I was suggested to add a muffler for back pressure since I’m currently catless and muffler less. Will these give me the back pressure needed for the performance and maintaining the loudness I love so much?! 1 answer

This exhaust would help you get the back pressure you need while maintaining the loudness of your exhaust. While it won't be as loud as it currently is without mufflers it would keep the sound volume up there.

Helpful (0)

I have a question about this flowmaster outlaw ? Is it louder than a MBRP axle back which one is louder ?? 1 answer

The flowmaster outlaw will be louder than the MBRP exhaust.

Helpful (0)

how do these compare to the corsa extreme axlebacks?? 1 answer

The Flowmaster Outlaw Axle-Back Exhaust will be close in loudness to the Corsa Extreme, but slightly louder. Tone wise both will be similar, and very raspy/racey.

Helpful (0)

From what I've read about the outlaws they have a mean rumble, do they have any crackle to them? 1 answer

The outlaws will have a crackle to them as well yes.

Helpful (0)

Customer Reviews (100+) Write a Review

Overall Rating

4.9

out of 5 stars

Installation Time:Afternoon

Installation Cost:0-$100

Loudness / Volume 4.801105 4.8
Exhaust Note 4.867036 4.9
Fit & Finish 4.627072 4.6
Bang For Your Buck 4.739612 4.7

5/5

Installation Time: Less than 1 Hour

October 29, 2019

Flowmaster outlaw axle back

They have my 09 GT sounding great easy to install. It has a deep tone. My neighbors love at 5 in the morning lol

ToddA

Year: 2009 Submodel: GT

Helpful (0) Thanks for your input!

Loudness (Volume) 4
4
Fit & Finish 5
5
Bang for your Buck 4
4

5/5

Installation Time: Less than 1 Hour

September 19, 2019

Flowmaster outlaw axle-back

Very easy to install. You CANNOT beat the sound of this for the GT500!

Bettatrain9

Year: 2008 Submodel: GT500

Helpful (0) Thanks for your input!

Loudness (Volume) 5
5
Exhaust Note 5
5
Fit & Finish 5
5
Bang for your Buck 4
4

4/5

Installation Time: Shop Install

Installation Cost: 0-$100

July 30, 2019

Good

Good exhaust, it is not super loud but it does have a nice american muscle sound. Would pair this up with x pipes if you want really loud. Would’ve preferred a bet more kick to the sound but it’s still good.

MannyB

Year: 2006 Submodel: GT

Helpful (0) Thanks for your input!

Loudness (Volume) 3
3
Exhaust Note 4
4
Fit & Finish 5
5
Bang for your Buck 3
3

5/5

Installation Time: Shop Install

Installation Cost: $100-$250

April 20, 2019

Sounds really good

Alot more aggressive than stock mufflers made a good difference worth the money

Outlaw

Year: 2010 Submodel: GT

Helpful (0) Thanks for your input!

Loudness (Volume) 5
5
Exhaust Note 5
5
Fit & Finish 5
5
Bang for your Buck 5
5

5/5

Installation Time: Less than 1 Hour

March 30, 2019

Thumbs up

I had pypes violater they seemed to low for me so I ordered the oulaw and they made a huge difference on the sound off the car . The install was easy mufflers fit perfect took me like 1 hour 30 minutes .

Wow

Year: 2007 Submodel: GT

Helpful (0) Thanks for your input!

Loudness (Volume) 5
5
Exhaust Note 5
5
Fit & Finish 5
5
Bang for your Buck 5
5

5/5

March 22, 2019

Good sound kinda overrated

Threw them on in the driveway in about a hour. Much louder than stock but i think they could be louder imo. Not too cool with the quality of the welds on the muffler but thats not AMs fault. Overall its ight

KingSlayer

Year: 2005 Submodel: GT

Helpful (4) Thanks for your input!

Loudness (Volume) 3
3
Exhaust Note 3
3
Fit & Finish 5
5
Bang for your Buck 3
3

5/5

Installation Time: Less than 1 Hour

March 22, 2019

go flow

im happy to hear her talk.....and she does.....i would recommend this.

RogerB

Year: 2006 Submodel: GT

Helpful (0) Thanks for your input!

Loudness (Volume) 4
4
Exhaust Note 4
4
Fit & Finish 5
5
Bang for your Buck 4
4

5/5

Installation Time: Afternoon

March 17, 2019

Wow! Deep Bass

What a sound! You can actually feel it in the seat of your pants. Fairly easy install and terrific sound when done. Hardest part was getting to the hanger bolts behind the old exhaust. If you had a lift, it would probably take about an hour to install.

JayS

Year: 2008 Submodel: GT

Helpful (0) Thanks for your input!

Loudness (Volume) 5
5
Exhaust Note 5
5
Fit & Finish 5
5
Bang for your Buck 5
5

5/5

Installation Time: Afternoon

March 16, 2019

Awsome

Nice deep sound and legal. I definitely recomend this exhaust.

Chad

Year: 2008 Submodel: GT

Helpful (0) Thanks for your input!

Loudness (Volume) 4
4
Exhaust Note 5
5
Fit & Finish 5
5
Bang for your Buck 5
5

5/5

Installation Time: Less than 1 Hour

March 05, 2019

Great exhaust. Perfect sound

This exhaust is loud but when your in lower rpms it is definitely a mellow sound. This was the perfect exhaust for me and it’s my daily driver. I would 100 recommend.

colbynabarrette

Year: 2006 Submodel: GT

Helpful (0) Thanks for your input!

Loudness (Volume) 5
5
Exhaust Note 5
5
Fit & Finish 5
5
Bang for your Buck 5
5

5/5

Installation Time: Afternoon

February 21, 2019

Loud and legal

Louder than I could ever imagine and I LOVE IT! Best sounding exhaust I’ve ever heard and it’s so loud. I can’t even imagine how loud it will be with a mid pipe and headers. If you are looking for an exhaust that is moderately loud this is not for you. If you want an exhaust that sounds like a bald eagle screaming in your ear then this is for you. At idle it’s loud. At about 2000 rpms which is about highway speed in 5th gear it is extremely loud to a point where one might find it obnoxious but not me because I love the sound of freedom.

Logan

Year: 2006 Submodel: GT

Helpful (1) Thanks for your input!

Loudness (Volume) 5
5
Exhaust Note 5
5
Fit & Finish 4
4
Bang for your Buck 5
5

5/5

Installation Time: Afternoon

February 14, 2019

Flowmaster Outlaw Axel-Back Exhaust

They were a good purchase! They make a big difference in the sound of your Mustang. If your looking for an aggressive exhaust for a low price this is definitely the best option.

Ethan

Year: 2010 Submodel: GT

Helpful (2) Thanks for your input!

Loudness (Volume) 5
5
Exhaust Note 5
5
Fit & Finish 5
5
Bang for your Buck 5
5

5/5

Installation Time: Less than 1 Hour

February 11, 2019

LOUD

if you want a super loud throaty sound you really cant go wrong with these.

PatrickF

Year: 2005 Submodel: GT

Helpful (1) Thanks for your input!

Loudness (Volume) 5
5
Exhaust Note 5
5
Fit & Finish 5
5
Bang for your Buck 5
5

5/5

February 04, 2019

Outlaws

installed in little over and hr ,useing 13 mm and 15 mm ,,easy. sound is AWESOME, 5.4 L SUPERCHARGED,

IraW

Year: 2008 Submodel: GT500

Helpful (2) Thanks for your input!

Loudness (Volume) 4
4
Exhaust Note 5
5
Fit & Finish 5
5
Bang for your Buck 5
5

4/5

Installation Time: Afternoon

January 29, 2019

Great buy!

Great sound. I’m told it’s real loud outside the car. Doesn’t seem so much from the inside. I love them. Before you plan on doing the install, check to see what is under the vehicle first. Even if the exhaust is stock somebody could have welded on the mufflers.

Year: 2006 Submodel: GT

Helpful (1) Thanks for your input!

Loudness (Volume) 4
4
Exhaust Note 5
5
Fit & Finish 4
4
Bang for your Buck 4
4

5/5

Installation Time: Less than 1 Hour

January 17, 2019

Looks and Sounds Amazing!

Took literally 30 min to install. Luckily my neighbor use to be a mechanic. Straight forward easy install. Watch the video! The sound is like a roaring lion. It is loud and resonates at certain rpm. But that’s really how a Mustang should sound. Definitely would recommend.

WMee

Year: 2005 Submodel: GT

Helpful (2) Thanks for your input!

Loudness (Volume) 5
5
Exhaust Note 5
5
Fit & Finish 5
5
Bang for your Buck 5
5

5/5

Installation Time: Less than 1 Hour

December 26, 2018

Great sound

Sounded great and was easy to install looks good would tell anybody wants aggressive sound to get

Duane

Year: 2007 Submodel: GT500

Helpful (2) Thanks for your input!

Loudness (Volume) 5
5
Exhaust Note 5
5
Fit & Finish 5
5
Bang for your Buck 5
5

5/5

Installation Time: Less than 1 Hour

December 24, 2018

UPGRADE - Order these....NOW!

Originally had Pypes Violators and they just didn't cut it for me (had Outlaws on a 2014 I had so I knew the deal). The Pypes were on when I bought the car and I was finally able to order these. They have an amazing sound, fit perfectly, and installed quickly with provided hardware. Might have to pull straight in garage now - wife says they're LOUD and might wake the baby when I leave for work (lol, oops)!

David

Year: 2008 Submodel: GT

Helpful (2) Thanks for your input!

Loudness (Volume) 5
5
Exhaust Note 5
5
Fit & Finish 5
5
Bang for your Buck 5
5

5/5

December 22, 2018

Bad Pipes

WOW!!!!! Easy bolt up and paired with BBK Shorty Headers the sound is just amazing!!!! Look great tips and bad black bodies

JohnT

Year: 2010 Submodel: GT

Helpful (2) Thanks for your input!

Loudness (Volume) 5
5
Exhaust Note 5
5
Fit & Finish 5
5
Bang for your Buck 5
5

5/5

Installation Time: Less than 1 Hour

December 20, 2018

Sounds like death lol

Loud....very loud. I don't even have long tube headers yet and it's still a very significant difference versus stock exhaust . You will wake neighbors

Teecee

Year: 2010 Submodel: GT

Helpful (3) Thanks for your input!

Loudness (Volume) 5
5
Exhaust Note 5
5
Fit & Finish 5
5
Bang for your Buck 5
5

Flowmaster Outlaw Axle-Back Exhaust (05-10 GT, GT500)

Features, Video & Details

Product Resources

Review & Installation Video

Review & Install Video

Add a fitment exception for Flowmaster Outlaw Axle-Back Exhaust (05-10 GT, GT500)

Customer Photos (84) Submit Your Photo

Questions & Answers (59)

5 Top Rated Questions

10 More Questions

Customer Reviews (100+) Write a Review

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Flowmaster Outlaw Axle-Back Exhaust (05-10 GT, GT500)

Features, Video & Details

Product Resources

Review & Installation Video

Review & Install Video

Add a fitment exception for Flowmaster Outlaw Axle-Back Exhaust (05-10 GT, GT500)

Customer Photos (84) Submit Your Photo

Questions & Answers (59)

5 Top Rated Questions

10 More Questions

Customer Reviews (100+) Write a Review

Related Mustang Categories

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Flowmaster Outlaw Axle-Back Exhaust (05-10 GT, GT500)