Kooks 18-24 Ford Mustang GT 5.0 3in. Valved Touring Cat-Back Exhaust - Carbon Tips

Refined Power With an Active Voice: The Touring-Tuned Valved Cat-Back for the S550 Mustang GT 5.0

The Kooks 11514570 delivers the performance and driver-controlled sound of a fully valved 3-inch cat-back exhaust on 2018 through 2024 Ford Mustang GT 5.0L 4V Coyote V8 models, specifically engineered for owners who want active exhaust versatility with a quieter, more refined closed-valve character than the shotgun-style alternative. Where the Kooks 11514520 uses shotgun muffler cores that produce an aggressively loud sound even with valves closed, the 11514570 employs touring-style valved muffler sections that reduce low-frequency drone during highway cruising and daily driving while preserving full open-valve aggression when the driver demands it. Both systems share the same 2-1/4 inch to 3-inch H-pipe, 3-inch mid-pipe, and 3-inch rear pipe architecture, so flow and performance capability are identical. The difference is entirely in how the closed valves sound and feel at part throttle.

Kooks constructed the 11514570 from T304 aircraft-quality stainless steel with mandrel-bent 3-inch tubing throughout. The active valve mechanism integrates with the factory active exhaust system on Mustangs so equipped, allowing the factory mode selector to operate the valves normally. On non-active-exhaust Mustangs, a compatible aftermarket controller or bypass can be used. The system ships with carbon fiber quad tips and uses OEM hanger positions throughout for a direct replacement installation that requires no cutting, welding, or modification to the vehicle. Every 11514570 is built to order in the USA and is designed exclusively for Mustang GT models with factory quad tip bumper cutouts.

Key Features

• Touring Valved Muffler Sections: Closed-valve sound is quieter and more refined than the shotgun version, reducing drone on the highway and during light throttle driving while retaining full open-valve aggression. This is the defining difference between the 11514570 and the 11514520.
• 3-Inch Stainless Throughout: Mandrel-bent T304 stainless steel at 3-inch diameter from the H-pipe through the rear pipes ensures maximum exhaust flow with no restrictions downstream of the factory catalytic converters.
• 2-1/4 in. x 3 in. H-Pipe: The H-pipe crossover balances cylinder bank exhaust pulses for improved mid-range torque and a fuller, deeper exhaust character compared to X-pipe designs at street RPM ranges.
• Active Exhaust Compatible: Valve actuation integrates with the factory active exhaust system on S550 Mustangs so equipped. The system includes the bypass required for active exhaust-equipped vehicles so factory controls operate the valves correctly.
• Carbon Fiber Quad Tips: Four carbon fiber-finished tips exit through the factory bumper cutouts and complement the Mustang GT's performance appearance without requiring bumper modification.
• Requires Factory Quad Tip Bumper: This system is only compatible with Mustangs that have factory quad exhaust tip bumper cutouts. Single or dual outlet bumpers require a different exhaust configuration.
• Drone Reduction vs. Shotgun: If minimizing highway drone is a priority while retaining the option for open-valve intensity, the 11514570 touring muffler is the correct choice over the 11514520 shotgun configuration.
• Handcrafted in the USA: Every Kooks 11514570 is built to order at Kooks' Statesville, North Carolina facility with the same quality standards applied across the full Kooks product line.

What's Included

• 2-1/4 in. x 3 in. H-Pipe Crossover Section in T304 Stainless Steel
• Pair of 3-Inch T304 Stainless Steel Mid-Pipes
• Pair of 3-Inch T304 Stainless Steel Rear Pipes with Touring Valved Muffler Sections
• Carbon Fiber Quad Exhaust Tips
• Active Exhaust Bypass for Factory Active Exhaust-Equipped Vehicles
• OEM-Compatible Mounting Clamps and Hardware
• Installation Manual

Install Instructions

1. Raise and support the Mustang on a lift or four jack stands at the factory-specified jacking points. Allow the factory exhaust to cool completely before beginning work.
2. Confirm the vehicle has factory quad exhaust tip bumper cutouts before proceeding. The 11514570 is not compatible with single or dual outlet bumper configurations.
3. Disconnect the negative battery terminal. Locate the factory active exhaust wiring connector if the vehicle is equipped with the factory active exhaust system.
4. Spray penetrating oil on all clamp hardware and hanger connections at the factory cat-back joints. Allow soak time before attempting removal.
5. Loosen and remove the factory clamp at the OEM connection point behind the factory catalytic converters. Remove the factory mid-pipes, H or X pipe, mufflers, and tips as a complete assembly by releasing all OEM hanger pucks from the body hanger rubbers.
6. On active exhaust-equipped vehicles, install the supplied bypass connector at the factory active exhaust actuator location per the Kooks installation manual instructions before installing the new system.
7. Install the Kooks 2-1/4 in. x 3 in. H-pipe at the OEM connection point. Leave all clamps hand-tight at this stage to allow alignment adjustment throughout the assembly process.
8. Install the driver and passenger 3-inch mid-pipes, connecting to the H-pipe and engaging the subframe hanger rubbers.
9. Install the touring valved muffler sections to the mid-pipes. Engage the muffler body hanger rubbers with the OEM body hanger positions.
10. Install the carbon fiber quad tips onto the muffler outlets. Align the tips evenly within the factory bumper cutouts and confirm equal protrusion on all four outlets.
11. Working from front to rear, final-tighten all clamps to the specified torque. Recheck tip alignment before fully tightening the rearmost clamps.
12. Reconnect the negative battery terminal. Start the engine and cycle through the active exhaust modes if equipped to confirm valve operation. Inspect all connections for exhaust leaks at the flanges and clamp joints.

Touring vs. Shotgun: Choosing the Right Kooks Valved Cat-Back

Kooks offers the 2018 through 2024 Mustang GT 5.0L valved cat-back system in two distinct muffler configurations. The 11514570 Touring uses touring-style valved muffler sections that significantly reduce highway drone and produce a quieter, more controlled sound signature with the valves in the closed position. This makes it suitable for daily driving and longer highway trips where exhaust drone at cruise RPM is a concern. The 11514520 Shotgun uses shotgun-style muffler cores that are inherently louder even with valves closed, producing a more aggressive and immediately noticeable tone at all times. Both systems use the same 3-inch pipe diameter, the same 2-1/4 in. x 3 in. H-pipe geometry, and the same carbon fiber quad tips. The correct choice depends entirely on the closed-valve sound character the owner wants for daily use. Open-valve intensity is comparable between both configurations.

Product Specifications

This Part Fits

Frequently Asked Questions

Q: What is the difference between the Kooks 11514570 and the 11514520?
A: Both systems use the same 3-inch pipe diameter, the same 2-1/4 in. x 3 in. H-pipe, and the same carbon fiber quad tips. The 11514570 uses touring-style valved muffler sections for a quieter, less droning closed-valve sound that is better suited to daily driving and highway use. The 11514520 uses shotgun-style muffler cores that produce a louder, more aggressive sound even with valves fully closed. Open-valve performance and flow are comparable between both systems.

Q: Will the 11514570 fit a Mustang GT350, GT500, Mach 1, or EcoBoost model?
A: No. The 11514570 is engineered exclusively for the Mustang GT with the 5.0L 4V Coyote V8. The GT350 uses a Voodoo flat-plane V8 with a different exhaust layout, the GT500 uses a supercharged 5.2L with its own exhaust architecture, and the Mach 1 uses specific exhaust routing that differs from the standard GT. The EcoBoost uses a 2.3L turbocharged four-cylinder with an entirely different system.

Q: My Mustang GT does not have the factory active exhaust. Can I still install the 11514570?
A: Yes. On non-active-exhaust Mustangs, the valves can be operated via an aftermarket exhaust controller or left in a fixed open or closed position. The supplied bypass connector handles the wiring on active exhaust vehicles. Contact Kooks or a professional installer for guidance on controller options for non-active exhaust applications.

Q: Does the 11514570 require Kooks long tube headers?
A: No. The system connects at the OEM connection point behind the factory catalytic converters and is fully functional as a standalone cat-back upgrade without Kooks headers. Pairing the 11514570 with Kooks long tube headers and a matching mid-pipe maximizes horsepower and torque gains.

Q: Does my Mustang need to have the factory quad tip bumper to use the 11514570?
A: Yes. Kooks specifically notes that the 11514570 only fits Mustangs that already have quad exhaust tip bumper cutouts. Mustangs with single or dual outlet bumper configurations require a different cat-back system.

Q: Will I need a tune after installing the 11514570?
A: A tune is not required for the vehicle to operate normally with the 11514570. However, a professional ECU tune optimized for improved exhaust flow will extract additional horsepower and torque beyond what the factory calibration produces.

Q: What is the lead time on the Kooks 11514570?
A: Every 11514570 is built to order at Kooks' USA facility. Current lead time is typically 10 to 12 weeks. Contact the seller for current production timelines at the time of order.

Q: What warranty does the Kooks 11514570 carry?
A: Kooks provides a limited lifetime warranty on all stainless steel components to the original purchaser. Coverage is governed by the Magnuson-Moss Warranty Act, meaning that installing this exhaust system cannot void the vehicle's factory powertrain warranty solely because of the modification. Warranty claims are processed through Kooks Custom Headers.

Q: Is the Kooks 11514570 legal in California?
A: This system is not CARB-approved and cannot be legally installed on registered street vehicles in California or other CARB-regulated states. It does not carry a CARB Executive Order number.

Why Kooks

• Over 60 years of American-made exhaust excellence with documented wins in the NHRA, IHRA, NMCA, NMRA, NASCAR, NASA, and SCCA.
• Every unit is hand-TIG-welded and inspected before leaving the Statesville, North Carolina facility.
• Limited lifetime warranty backed by six-plus decades of stainless fabrication expertise and race-proven quality.

California Proposition 65 Warning: This product can expose you to chemicals including Chromium and Nickel, which are known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information go to www.P65Warnings.ca.gov.