18-23 Ford Musang GT 5.0L V8 Flowmaster 817821 Outlaw Axle-back Exhaust System

Flowmaster Outlaw Axle-Back Exhaust System | Part #817821

Transform the sound and appearance of the 2018-2023 Ford Mustang GT 5.0L with the Flowmaster Outlaw Axle-Back Exhaust System, Part #817821. Engineered specifically for Mustang GT coupes and convertibles without the factory Active Performance Exhaust Valves, this premium performance exhaust delivers the unmistakable aggressive tone that Flowmaster's race-proven Outlaw mufflers are known for. Constructed from durable 409 stainless steel with mandrel-bent 3.00-inch tubing, this direct-fit axle-back system improves exhaust flow while maintaining excellent durability for years of performance driving. The quad 4.00-inch polished 304 stainless steel exhaust tips provide an eye-catching factory-style appearance that perfectly complements the Mustang's aggressive styling. Designed as a bolt-on upgrade that utilizes the factory hanger locations, this system includes all necessary hardware and installation instructions, making it an excellent choice for enthusiasts seeking enhanced sound, premium quality, and long-lasting performance.

Key Features

• Flowmaster Outlaw Axle-Back Exhaust System
• Fits 2018-2023 Ford Mustang GT 5.0L Coupes and Convertibles without Factory Active Performance Exhaust Valves
• Race-proven Outlaw reflection-style mufflers deliver an aggressive exhaust note
• Mandrel-bent 3.00-inch 409 stainless steel tubing for improved exhaust flow
• Large quad 4.00-inch polished double-wall 304 stainless steel exhaust tips
• Dyno-tuned to maximize performance and exhaust efficiency
• Retains the factory resonator mid-pipe
• Uses factory hanger locations for a precise, direct-fit installation
• Includes clamps, hardware, and detailed installation instructions
• Bolt-on axle-back design with factory-style fit and finish

Benefits

• Produces an aggressive exterior exhaust tone with a noticeable interior sound for an authentic muscle car experience.
• Enhances the Mustang GT's appearance with premium polished quad exhaust tips.
• Improves exhaust flow while maintaining excellent durability through stainless steel construction.
• Designed specifically for a precise fit without unnecessary modifications beyond the required factory muffler cut.
• Maintains compatibility with the factory rear valance and exhaust cutouts.
• Backed by Flowmaster's Limited Lifetime Warranty for long-term confidence and peace of mind.
  

Product Specifications

• Part Number: 817821
• Product Type: Axle-Back Exhaust System
• Exhaust Series: Outlaw
• Sound Level: Aggressive
• Main Pipe Diameter: 3.00 inches
• Pipe Material: 409 Stainless Steel
• Pipe Finish: Natural
• Muffler Material: 409 Stainless Steel
• Muffler Finish: Black High-Temperature Paint
• Muffler Type: Reflection
• Muffler Quantity: 2
• Exhaust Tip Material: 304 Stainless Steel
• Exhaust Tip Diameter: 4.00 inches
• Exhaust Tip Length: 5.25 inches
• Exhaust Tip Finish: Polished
• Exhaust Tip Color: Silver
• Exhaust Tip Style: Round, Double-Wall, Angle-Cut
• Tip Quantity: 4
• Exit Style: Dual Rear Exit
• Inlet Connection: Slip-Fit
• Clamping Type: Flat Band
• Clamps Included: Yes
• Hangers Included: Yes
• Mounting: Uses Factory Hanger Locations
• Catalytic Converter Included: No
• Valve Included: No
• UPC: 700042038152

Install Difficulty Level

Easy. This axle-back exhaust system is designed as a direct-fit upgrade that reuses the factory hanger locations and includes the required hardware and installation instructions. The factory mufflers must be cut from the original mid-pipe before installation, but no welding is required for a standard installation. Under ideal conditions, installation can be completed in approximately 1 hour, making it an excellent weekend upgrade for most DIY enthusiasts with basic hand tools.

Vehicle Fitment

Fits the following vehicles:

• 2018 Ford Mustang GT Coupe – 5.0L V8 (Without Factory Active Performance Exhaust Valves)
• 2018 Ford Mustang GT Convertible – 5.0L V8 (Without Factory Active Performance Exhaust Valves)
• 2019 Ford Mustang GT Coupe – 5.0L V8 (Without Factory Active Performance Exhaust Valves)
• 2019 Ford Mustang GT Convertible – 5.0L V8 (Without Factory Active Performance Exhaust Valves)
• 2020 Ford Mustang GT Coupe – 5.0L V8 (Without Factory Active Performance Exhaust Valves)
• 2020 Ford Mustang GT Convertible – 5.0L V8 (Without Factory Active Performance Exhaust Valves)
• 2021 Ford Mustang GT Coupe – 5.0L V8 (Without Factory Active Performance Exhaust Valves)
• 2021 Ford Mustang GT Convertible – 5.0L V8 (Without Factory Active Performance Exhaust Valves)
• 2022 Ford Mustang GT Coupe – 5.0L V8 (Without Factory Active Performance Exhaust Valves)
• 2022 Ford Mustang GT Convertible – 5.0L V8 (Without Factory Active Performance Exhaust Valves)
• 2023 Ford Mustang GT Coupe – 5.0L V8 (Without Factory Active Performance Exhaust Valves)
• 2023 Ford Mustang GT Convertible – 5.0L V8 (Without Factory Active Performance Exhaust Valves)

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