Flowmaster 817799 American Thunder Axle-Back System for 18-23 Mustang GT w/factory exhaust valves


  • $1,630.95
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Fits 2018-2023 Mustang GT 5.0L with Factory Active Performance Exhaust Valves. - Aggressive to moderate sound

This Flowmaster® American Thunder® Axle-back exhaust system is for 2018-2023 Ford Mustang GT coupes and convertibles with the 5.0L engine and Factory Active Performance Exhaust Option. System features include a pair of specially designed Outlaw® series mufflers giving you high flow with a moderately aggressive exterior and interior tone when the valves are closed, and an aggressive "wide open" exterior sound level when you open up the valves. Other features include large 3.00-inch mandrel-bent 409S stainless steel tubing for high flow, durability, and longevity. Add to that, a pair of our high-quality valves to accommodate the factory exhaust actuators for when you really want to open up the sound. The system is finished off with quad 4.00-inch polished 304 stainless steel tips for an aggressive look that demands attention, the same as the exhaust note. Includes all necessary parts, hardware and detailed instructions for an easy installation you can do at home. Covered by our Lifetime Limited Warranty. Note: Fits both coupes and convertibles.


  • Quad 4.00-inch Polished 304 Stainless Steel Tips
  • For Vehicles With Active Performance Exhaust Option
  • Aggressive Race-proven Outlaw Mufflers
  • Dyno Tuned for Maximum Performance
  • Uses the Factory Hanger Locations
  • Full Stainless Steel Construction
  • Straight-through Muffler Design
  • Lifetime Limited Warranty
  • Easy Installation
Brand Flowmaster
Catalytic Converter Included No
Emission Code 5
Exhaust Series American Thunder
Exit Position Dual Out Rear
Heat Shield No
Material 409 Stainless Steel
Mount Type Uses Factory Hangers
Muffler Body Length (in) 11
Muffler Color Black
Muffler Finish Painted
Muffler Inlet Diameter (in) 3
Muffler Inlet Location Side
Muffler Material 409S Stainless Steel
Muffler Outlet Diameter (in) 3
Muffler Outlet Location Dual
Muffler Overall Length (in) 49.5
Muffler Part Number Kit Only
Muffler Quantity 2
Muffler Series 60 Series
Muffler Shape Oval
Muffler Type Reflection
Product Type Exhaust System
Single Dual Dual
Sound Level Aggressive / Moderate
System Type Axle-back
Tip Cut Angle
Tip Diameter (in) 4
Tip Edge Style Cut
Tip Finish Polished
Tip Length (in) 5.25
Tip Logo Embossed
Tip Material 304 Stainless
Tip Quantity 4
Tip Shape Round
Tubing Diameter (in) 3
Tubing Material 409S Stainless Steel
UPC 700042037766
California Proposition 65 Chemical Name Chromium (hexavalent compounds)
Nickel (Metallic)
California Proposition 65 Required Yes
Part Number 817799

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