Exhaust Cutouts

What Exhaust Cutouts Do

An exhaust cutout adds a bypass valve to your exhaust that opens a second path for gases, so you can switch between a quiet street setup and an open, aggressive tone. When the cutout is closed, your exhaust flows normally through the mufflers and tailpipes. When it's open, gases exit ahead of the muffler, cutting back pressure and letting the engine breathe more freely.

Builders use cutouts for track days, car shows, and weekend driving where a louder note and freer flow matter. You get the sound of an open exhaust without permanently gutting your system, which is why cutouts pair well with headers and high-flow parts. For a deeper look at how a bypass valve changes sound and flow, read our Granatelli exhaust cutout guide before you choose a setup.

Electric vs. Manual Exhaust Cutouts

The difference comes down to how you open the bypass: an electric exhaust cutout uses a motorized valve you control from the cabin, while a manual exhaust cutout uses a capped pipe or lever you open by hand. Electric systems are the easy, everyday choice, and manual kits cost less while keeping things simple.

Here's how the main types compare:

• Electric exhaust cutout: opens with a switch or remote so you can change your sound from the driver's seat.
• Manual exhaust cutout: opens by hand at the pipe, keeping cost down and the design simple.
• Electric cutout kit: bundles the valve, wiring, and switch for a cleaner, more complete install.
• Remote exhaust cutout: adds a wireless fob so you can toggle flow without reaching for a dash switch.

If you already run a motorized valve setup, matching it with the right exhaust valve actuators keeps your system responsive and reliable.

Types of Exhaust Cutouts and Kits

JEGS carries every major cutout style, from single valves to complete pipe kits, so you can match the design to your car and your install skills. Weld-in cutouts drop into a cut section of pipe for a permanent, leak-free fit, while slip-fit cutouts clamp on with band clamps for a bolt-on approach.

Beyond the valve itself, you'll find electric cutout systems, manual cutout kits, cutout valves, illuminated push-button switches, butterfly kits, connection tubes, and Y transition adapters. Kits often bundle the parts you need so you're not sourcing clamps and tubes separately.

Cutouts also play well with the rest of your setup. Add a set of exhaust tips to finish the look at the bumper, or route spent gases downward with exhaust turndowns when you want to keep exit noise low. Pick the combination that fits your build and how often you'll run the bypass open.

Do Exhaust Cutouts Add Horsepower?

Exhaust cutouts can free up power, but the gains depend on how restrictive your current exhaust is. Opening the bypass reduces back pressure ahead of the muffler, which helps a built engine breathe on the top end. On a stock or lightly modified car, the difference is usually modest, and the bigger payoff is sound.

The more restrictive your mufflers and resonators are, the more an open cutout tends to help. Engines with headers, larger piping, and higher airflow see the clearest benefit because the exhaust downstream is the bottleneck. Think of a cutout as a switch that removes that restriction when you want it, not a guaranteed dyno number.

If you're chasing real flow gains, review your whole exhaust path first. Our muffler types guide breaks down how different muffler designs trade sound for flow, so you can decide what to keep and what to open up.

Choosing the Right Size and Fit

Match your cutout size to your existing exhaust pipe so flow stays smooth and the valve seals correctly. JEGS stocks cutouts from 2.25 in. to 4 in., including common 2.5 in. and 3 in. sizes, so you can mirror your current piping diameter. Going larger than your pipe won't add flow if the rest of the system is smaller.

Material matters for how long the cutout lasts. Stainless steel, including T-304, resists rust and heat for a long service life, while aluminized mild steel costs less and works well for budget builds. Weld-in designs need fabrication, and slip-fit designs install with band clamps.

Confirm your pipe diameter, pick weld-in or slip-fit, then choose the material that fits your climate and budget. If you're upgrading the lines at the same time, size your exhaust piping to the cutout so everything matches and seals tight.