What Is an Exhaust Cutout and How Do You Choose the Right One?

Updated

An exhaust cutout is a valve installed in an exhaust system that opens a path for exhaust gas to exit before it reaches the muffler and rear piping. When closed, exhaust flows normally and the vehicle stays quiet; when opened, exhaust takes the shorter, less restricted path, which typically increases sound and can reduce backpressure. Electric cutouts use a motor and switch (or remote) to open and close the valve from the driver's seat, while manual cutouts require loosening bolts or removing a plate by hand. Quick Time Performance (QTP) builds electric cutouts and related exhaust components in the USA, and its site organizes cutouts by type—standard electric, low profile, DIY fabricator, and Aggressor—plus separate categories for wireless remote controllers and clips, Screamer and TwinTronic exhaust systems, eliminators, and AR3 mufflers.

How an exhaust cutout works

A cutout is essentially a Y-branch in the exhaust with a valve on the branch:

  • Closed: exhaust continues through the factory or aftermarket muffler and tailpipe. Sound and emissions behavior stay close to stock.
  • Open: exhaust exits through the cutout opening, bypassing the muffler and much of the rear piping. This is why cutouts are sometimes called "screamers"—the sound increase is the main reason most people install them.
  • Partially open: electric valves can often be positioned anywhere between fully closed and fully open, letting you tune the volume rather than choosing only loud or quiet.

The performance effect depends on the rest of the system. Reducing backpressure can help a turbocharged or heavily modified engine in some setups, but on a mostly stock engine the gain is usually small and the sound change is the bigger, more noticeable result.

Electric vs manual cutouts

Feature Electric cutout Manual cutout
Operation Switch, button, or wireless remote from inside the vehicle Unbolt a plate or turn a manual valve by hand
Convenience Open or close while driving Requires stopping and getting under the car
Wiring Needs power and a switch or remote kit None
Typical use Street cars where sound is changed often Track cars, fabricators, or budget builds

QTP's catalog separates these needs directly: standard Electric Exhaust Cutouts, Low Profile Electric Cutouts for tight clearance, DIY Fabricator Electric Cutouts for custom builds, and Aggressor Electric Cutout Pipes. If you want to control the valve without running a switch into the cabin, the Wireless Remote Controllers and Clips category covers that.

Matching cutout size to your exhaust pipe

Cutouts are sized by pipe diameter, and QTP notes that its electric cutouts are universal by design and sorted according to your existing exhaust pipe size. That means:

  1. Measure your exhaust pipe's outside diameter at the spot where you plan to install the cutout.
  2. Select the cutout size that matches that diameter.
  3. If your vehicle isn't listed in the Shop By Vehicle tool, use the pipe-size categories instead—the site explicitly directs customers there and offers contact for help.

Getting this wrong is the most common fitment mistake: a cutout that doesn't match the pipe either won't seal or won't clamp properly.

Installation considerations

  • Universal vs vehicle-specific: Cutouts themselves are universal by pipe size, but complete systems like the Screamer axle-back and cat-back kits are listed by vehicle (for example, 2016–2024 Chevrolet Camaro SS and 2018–2022 Jeep Grand Cherokee Trackhawk). Choose a full system if you want a matched, vehicle-specific fit; choose a standalone cutout if you're adding one to an existing exhaust.
  • Welding or clamping: Installing a cutout usually means cutting the exhaust pipe and welding or clamping the Y-section in place. Plan for the tools and skill this requires, or budget for a shop.
  • Wiring and routing: Electric cutouts need a power source and a switch or remote receiver mounted somewhere accessible. Route wiring away from hot exhaust surfaces.
  • Clearance: Low-profile cutouts exist specifically for vehicles with limited ground clearance or tight undercarriage space.

Common issues to expect

  • Leaks at the valve: A cutout that doesn't seal fully when closed can cause an exhaust leak, which may sound like a tick or drone at idle.
  • Wiring faults: Motors that stop responding are often a power, ground, or switch issue rather than a failed valve.
  • Legality and emissions: Opening a cutout can violate local noise ordinances and, in many places, tampering with emissions-related exhaust components is not street legal. Check your local rules before installing, and treat cutouts as off-road or show use where required.

Quick selection guide

  • Want to change sound from inside the car, mostly stock vehicle → standard electric cutout in your pipe size.
  • Tight clearance under the car → low profile electric cutout.
  • Building custom exhaust from scratch → DIY fabricator cutout.
  • Want a complete matched system → Screamer or TwinTronic system listed by vehicle.
  • No cabin switch wanted → electric cutout plus wireless remote controller kit.

If your vehicle isn't in the site's vehicle list, start from the pipe-size categories and confirm the diameter before ordering.