05-09 Ford Mustang V6 4.0L Flowmaster 17421 American Thunder Axle-back Exhaust System

Flowmaster American Thunder Axle-Back Exhaust System - Part #17421

The Flowmaster American Thunder Axle-Back Exhaust System (Part #17421) is engineered to give the 2005-2009 Ford Mustang V6 a deeper, performance-inspired exhaust note while enhancing the vehicle's iconic muscle car styling. Featuring durable 16-gauge mandrel-bent aluminized steel construction and a premium 60 Series Delta Flow chambered muffler, this system delivers a moderate yet aggressive exhaust tone that is ideal for daily driving and spirited weekend cruising. Designed as a direct-fit axle-back replacement, the system utilizes the factory hanger locations and includes all required installation hardware for a straightforward upgrade. Finished with a large polished 304 stainless steel exhaust tip, this exhaust not only improves appearance but also helps deliver better throttle response, increased exhaust flow, and the unmistakable Flowmaster sound Mustang enthusiasts expect.

Key Features

• Flowmaster American Thunder axle-back exhaust system.
• Part Number: 17421.
• Designed specifically for 2005-2009 Ford Mustang V6 models.
• Constructed from durable 16-gauge mandrel-bent aluminized steel.
• 60 Series Delta Flow chambered performance muffler.
• Moderate interior sound with a moderately aggressive exterior exhaust tone.
• Dyno-tuned to help maximize exhaust flow and performance.
• Large polished 304 stainless steel exhaust tip for an aggressive rear appearance.
• Uses factory mounting locations for a precise fit.
• Includes clamps, hangers, hardware, and installation components.
• Direct-fit axle-back design requires no major modifications.
• Compatible with both coupe and convertible models.

Benefits

• Produces the signature Flowmaster performance sound without excessive interior drone.
• Helps improve throttle response and overall engine efficiency.
• Supports increased exhaust flow for enhanced performance potential.
• Upgrades the Mustang's appearance with a polished stainless steel exhaust tip.
• Quality materials provide excellent durability for long service life.
• Bolt-on installation minimizes installation time and complexity.
• Backed by Flowmaster's Limited Lifetime Warranty for added confidence in long-term ownership.
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Product Specifications

• Brand: Flowmaster
• Part Number: 17421
• Product Type: Axle-Back Exhaust System
• Exhaust Series: American Thunder
• Material: 16-Gauge Mandrel-Bent Aluminized Steel
• Pipe Material: Aluminized Steel
• Pipe Finish: Aluminized
• Pipe Color: Black
• Main Pipe Diameter: 2.50 inches
• Inlet Diameter: 2.50 inches
• Inlet Connection: Slip-Fit Clamp-On
• Muffler Series: 60 Series Delta Flow
• Muffler Type: Chambered
• Muffler Material: Aluminized Steel
• Muffler Finish: Black High-Temperature Paint
• Muffler Shape: Oval
• Muffler Dimensions: 13.00 in. Length x 10.00 in. Width x 5.00 in. Height
• Exit Style: Single Rear Exit
• Exhaust Tip Material: Polished 304 Stainless Steel
• Exhaust Tip Diameter: 3.50 inches
• Exhaust Tip Length: 5.25 inches
• Exhaust Tip Shape: Round
• Exhaust Tip Edge: Rolled Angle Cut
• Exhaust Tip Wall: Single Wall
• Sound Level: Moderate
• Clamps Included: Yes
• Hangers Included: Yes
• Catalytic Converter Included: No
• Drive Type: 2WD

Install Difficulty Level

Easy. This direct-fit axle-back system is designed to install using the factory hanger locations and included hardware with no cutting or fabrication normally required. Basic hand tools are all that are typically needed, making this an excellent upgrade for DIY enthusiasts. Under ideal conditions, installation can be completed in as little as 30 minutes.

Vehicle Fitment

Fits the following vehicles:

• 2005 Ford Mustang 4.0L V6 - Coupe
• 2005 Ford Mustang 4.0L V6 - Convertible
• 2006 Ford Mustang 4.0L V6 - Coupe
• 2006 Ford Mustang 4.0L V6 - Convertible
• 2007 Ford Mustang 4.0L V6 - Coupe
• 2007 Ford Mustang 4.0L V6 - Convertible
• 2008 Ford Mustang 4.0L V6 - Coupe
• 2008 Ford Mustang 4.0L V6 - Convertible
• 2009 Ford Mustang 4.0L V6 - Coupe
• 2009 Ford Mustang 4.0L V6 - Convertible

For questions about this product or to report product description inaccuracies, contact the MPT Performance experts at (407) 636-7077 or by email.