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Flowmaster 17421 American Thunder Axle-Back Exhaust System

(2005-2009 Ford Mustang)

Part of: Flowmaster American Thunder Axle-Back Exhaust System

Other options in this family: Flowmaster 817942 Flowmaster 818162 Flowmaster 817746 Flowmaster 817460 Flowmaster 817743

Manufacturer

Picture for manufacturer Flowmaster

Part Number

17421
5 reviews
Sale Price

$478.95

In Stock (10)

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Usually delivered within 2 days

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Product Details

The Flowmaster American Thunder Axle-Back Exhaust System is engineered to deliver enhanced performance and an aggressive exhaust note for your vehicle. This cat-back system features Flowmaster's renowned 60 Series performance muffler, dyno-tuned to maximize horsepower and torque while providing that signature Flowmaster sound.

Key Features:

  • 60 Series performance muffler with moderate to aggressive exterior exhaust tone
  • Mandrel-bent 16-gauge aluminized steel tubing for improved exhaust flow
  • 4.00-inch polished stainless steel tip for a premium appearance
  • Uses factory hanger locations for straightforward bolt-on installation
  • Includes all necessary hangers and mounting hardware
  • Dyno-tested and tuned for optimal performance gains

This axle-back system provides an easy upgrade path for enthusiasts seeking improved sound and performance without extensive fabrication. The mandrel-bent tubing ensures smooth exhaust flow with minimal restriction, while the polished stainless tip adds a refined finishing touch. Designed as a direct replacement for your factory exhaust, this system installs using existing mounting points for a hassle-free installation experience.

Products specifications

Fits

2005-2009 Ford Mustang

Tip Diameter

3.500 in.

Outlet Outside Diameter

3.500 in.

System Type

Axle Back

Prop 65

WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov

California Proposition 65 Chemical Name 2

Chromium (hexavalent compounds)

California Proposition 65 Chemical Name 1

Nickel (metallic)

California Proposition 65 Chemical Name

Chromium (hexavalent compounds)

California Proposition 65 Chemical Name

Nickel (Metallic)

Heat Shield Attached

No

Color

Black

Material

Aluminized Steel

Muffler Count

1

Exhaust Type

Single

Exit Position

Single Rear

Tubing Diameter

2.500 in.

Outlet Diameter

2.500 in.

Tip Quantity

1

Tail Pipe Diameter

2.500 in.

Single or Dual

Single

Title

Flowmaster 17421 Axle-back System 409S - Single Rear Exit - American Thunder - Moderate Sound

Brand

Flowmaster

Catalytic Converter Quantity

0

Category

Exhaust

Clamping Type

Flat Band

Clamps Included

Yes

Drive

2WD

Emission Code

5

Exhaust Series

American Thunder

Exhaust Tip Connection

Welded

Exhaust Tip Cut

Angled

Exhaust Tip Edge

Rolled Edge Angle Cut

Exhaust Tip Finish

Polished

Exhaust Tip Intercooled

No

Exhaust Tip Length

5.25

Exhaust Tip Material

304 Stainless Steel

Exhaust Tip Quantity

1

Exhaust Tip Resonated

No

Exhaust Tip Shape

Round

Exhaust Tip Wall

Single Wall

Exit Style

Single Out Rear

Finish

Aluminized

Gasket Or Seal Included

No

Grade Type

Performance

Hangers Included

Yes

Heat Shield Included

No

Inlet Diameter

2.50

Inlet Type

Clamp-On

Mounting Bracket Included

No

Muffler Body Material

Aluminized Steel

Muffler Body Shape

Oval

Muffler Finish

Black High-Temperature Paint Finish

Muffler Flanged Inlet

No

Muffler Flanged Outlet

No

Muffler Inlet Connection

Slip-Fit

Muffler Outlet Quantity

1

muffler part number

Kit Only

Muffler Quantity

1

Muffler Series

60 Series Delta Flow

Muffler Type

Chambered

Pipe Color

Black

Pipe Material

Aluminized Steel

Product Type

Exhaust System

Sound Level

Moderate

Spring Bolt Kit Included

No

Sub Category

Exhaust and Tail Pipes

Tail Pipe Quantity

1

Tail Pipe Quantity

Single

Tail Pipe Tapered Outlet

No

Type

Axle-Back

Valve Included

No

Valve Type

Not Applicable

Warning

California Proposition 65

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