axle-back

Flowmaster 17421 - American Thunder Axle Back Exhaust System

Name: Flowmaster 17421 - American Thunder Axle Back Exhaust System (17421)
Brand: Flowmaster
SKU: 5b0001dc259b31d67f871338
Price: 333.95 USD
Availability: InStock
Rating: 5 (12 reviews)

(12)

$333.95

$372.00

You save: $38.05 (10%) off MSRP

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TOP MEMBER BUILDS RUNNING THIS MOD

Flowmaster 17421 - American Thunder Axle Back Exhaust System

This part fits

2009 Ford Mustang Base 4.0L V6 cid:245
2008 Ford Mustang Base 4.0L V6 cid:245
2007 Ford Mustang Base 4.0L V6 cid:245
2006 Ford Mustang Base 4.0L V6 cid:245
2005 Ford Mustang Base 4.0L V6 cid:245

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About this product

Part #: 17421

This aggressive sounding system is designed to replace the original rear mounted mufflers located behind the rear axle. With easy fit in mind, the system is mandrel bent for maximum performance and includes specially selected mufflers to support the performance image of the car. As an America Thunder system, it delivers an aggressive exterior tone with moderate interior sound level that is suited to the enthusiast who wants their performance to be heard. Like all Flowmaster systems, the benefits include improved throttle response, power and mileage. Designed for an easy fit, the system includes all necessary parts and hardware for easy installation.

Install photos (5)

For the American Thunder Axle Back Exhaust System

More Details

Color	Black
Exhaust Series	American Thunder
Exhaust Type	Single
Exit Position	Single Rear
Exit Style	Straight
Heat Shield Attached	No
Inlet Diameter	2.500 in.
Material	Aluminized Steel
Muffler Count	1
Muffler Part Number	Kit Only
Muffler Series	60 Series Delta Flow
Outlet Diameter	2.500 in.
Outlet Outside Diameter	3.500 in.
Single or Dual	Single
Sound Level	Moderate
System Type	Axle Back
Tail Pipe Diameter	2.500 in.
Tip Diameter	3.500 in.
Tip Quantity	1
Title	Flowmaster 17421 Axle-back System 409S - Single Rear Exit - American Thunder - Moderate Sound
Tubing Diameter	2.500 in.

Additional Documents

See what our community says about flowmaster products

254

Brett Moffett

1995 Ford Mustang

What made you choose this particular product?

Super 40'soft sound amazing...but drone makes them not family or neighbour friendly.

Is this your first time buying from this brand? Did you consider other brands?

Yes. I have used magna flow in the past, better for longer drives but not as nasty sounding...and I mean nasty in a good way!

View on Brett's build

Josh Elledge

2015 Ford Mustang

What made you choose this particular product?

Deep quality sound.

Is this your first time buying from this brand? Did you consider other brands?

No. And yes I considered a few different brands.

Was it easy to install? Any installation tips that will help others?

Yes.

Once you've had a chance to use the product, did it meet your expectations?

A little on the quiet sid but good sound

View on Josh's build

290

Michael Curbelo

1988 Ford Mustang

What made you choose this particular product?

The way it sounds on the car and the reviews that it got is what sold me on buying it

Is this your first time buying from this brand? Did you consider other brands?

I’ve had this brand before but of different mufflers and I was considering getting SLP loudmouth bullet style mufflers

Was it easy to install? Any installation tips that will help others?

Was easy to install everything bolted right up

Once you've had a chance to use the product, did it meet your expectations?

It exceeded my expectations

View on Michael's build

492

Brett Moffett

1995 Ford Mustang

What made you choose this particular product?

It came installed on the car when I purchased it.

Is this your first time buying from this brand? Did you consider other brands?

First time with this brand. I would consider going to Magnaflow or Borla again, although the Flowmasters do sound amazing, they are a bit loud for normal use.

Was it easy to install? Any installation tips that will help others?

Came installed on the car, but the fit is good.

Once you've had a chance to use the product, did it meet your expectations?

These make the car sound very aggressive, you can hear the car coming from the other side of my small town. So they sound bad ass...but can be annoying for your neighbours and police.

View on Brett's build

289

Nate Johnson

2006 Ford Mustang

What made you choose this particular product?

Previous owner installed it.

Is this your first time buying from this brand? Did you consider other brands?

Yes but it looks and sounds awesome!

Once you've had a chance to use the product, did it meet your expectations?

Sounds amazing for a v6

View on Nate's build

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Flowmaster - American Thunder Axle Back Exhaust System

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$333.95$372.00

Save $38.05 (10%) off MSRP

WARNING: Cancer and Reproductive Harm www.p65warnings.cs.gov

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About Flowmaster

Manufacturer of performance exhaust systems, mufflers, cold air intakes, turbo boost modules, catalytic converters, race mufflers, headers and numerous exhaust accessories for late model cars, trucks, off-road, Jeeps, SUV’s, classic muscle cars, powersports vehicles and more. Flowmaster® gives you lots of exhaust choices with 12 designs of chambered mufflers, 3 styles of our exclusive “laminar-flow” mufflers and a new line of FlowFX “straight-through” performance mufflers, along with 5 sound categories of exhaust systems, giving you the customer, the power to custom tailor the sound of your vehicle whether you prefer mild, moderate or aggressive tones and sound levels.

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