Understanding Exhaust Cutouts

Exhaust cutouts are aftermarket valves installed in a vehicle’s exhaust system that allow the driver to bypass the muffler or entire exhaust system on demand. When the cutout is closed, exhaust gases follow their normal path through the muffler, producing a quiet, refined sound. When open, the gases exit before the muffler, creating a raw, aggressive roar. This on-the-fly sound control makes cutouts a popular choice for show-goers who want to make an entrance without sacrificing daily drivability.

How Exhaust Cutouts Work

At its core, an exhaust cutout is a Y-pipe or inline valve placed in the exhaust stream before the muffler. The valve mechanism—typically a butterfly, gate, or disc—seals the secondary outlet when closed. When the driver activates the cutout, the valve swings open, diverting exhaust flow out a separate pipe and bypassing the muffler. The result is a dramatic increase in volume and a deeper, more aggressive tone. Many enthusiasts pair cutouts with aftermarket headers or a cat-back system for maximum effect.

Types of Exhaust Cutouts

Choosing the right cutout depends on your budget, how you plan to use the car, and your tolerance for installation complexity. Here are the main options:

Manual Cutouts

Manual cutouts are the simplest and most affordable. They consist of a valve with a lever or knob that must be physically moved to open or close. Some designs use a cable-operated system, while others require you to reach under the car. While reliable and inexpensive, manual cutouts are inconvenient for quick changes—you need to stop, get out, and adjust them by hand. They are best suited for dedicated show cars where the cutout will be left open for the entire event.

Electric Cutouts

Electric cutouts use a small motor or solenoid to open and close the valve. A switch inside the cabin—often a simple toggle or button—allows the driver to change the sound instantly without leaving their seat. Many electric cutout kits include a handheld remote control for operation from outside the vehicle, which is perfect for car shows or revving for a crowd. These systems are reliable, but they require wiring and a control module. Some high-end electric cutouts incorporate position sensors and programmable opening speeds.

Electronic / Wireless Cutouts

An evolution of the electric cutout, electronic or wireless cutout kits use radio frequency remotes and sometimes smartphone apps for control. They eliminate the need to run a physical switch into the cabin, simplifying installation. Premium units feature stainless steel construction, that will not rust over time. Some systems allow you to set a percentage open, giving you more granular control over the exhaust note rather than just on/off. These are ideal for car show enthusiasts who want precise sound tuning.

Installation Guide for Exhaust Cutouts

Proper installation is critical for performance, safety, and longevity. While every vehicle is different, the general process remains consistent. Below is a step-by-step outline, but always refer to the manufacturer’s instructions for your specific kit.

Tools and Materials You’ll Need

  • Exhaust cutout kit (valve, gaskets, bolts, wiring harness if electric)
  • Angle grinder with cutting wheel or a reciprocating saw
  • Welding equipment (MIG or TIG) or high-band exhaust clamps
  • Jack and jack stands or a lift
  • Safety glasses, gloves, and ear protection
  • Measuring tape, marker, and straight edge
  • For electric units: wire strippers, crimpers, heat shrink tubing, electrical tape

Step 1: Determine Cutout Location

The optimal location for a cutout is as close to the exhaust manifold or header collector as possible, but before the muffler. A common spot is on the downpipe or mid-pipe. Measure the available clearance to ensure the cutout valve and its outlet pipe will not hit the undercarriage, driveshaft, or other suspension components. For V8 engines, consider placing cutouts on both banks for a balanced sound. Mark the pipe where you will cut.

Step 2: Cut the Exhaust Pipe

Raise and secure the vehicle on jack stands. Use a grinder or saw to cut the exhaust pipe at the marked location. Make a clean, straight cut to ensure a good seal. Be careful of hot exhaust components if the vehicle has been running. Remove any burrs from the cut edges with a file.

Step 3: Install the Cutout Valve

Slide the cutout valve into place between the two pipe sections. If the cutout is a Y-style (branching off to a separate pipe), weld or clamp the main pipe inline and attach the branch outlet pipe. For an inline cutout (where the valve is part of the main pipe), you will weld or clamp the valve directly into the cut. Use your chosen method: welding provides a permanent, leak-free joint, while high-quality stainless steel clamps allow for future removal. Ensure the valve moves freely before tightening everything.

Step 4: Route the Outlet Pipe

Attach an extension pipe to the cutout’s open port if needed. The outlet should point toward the ground or a safe direction away from the vehicle’s underbody components. Some states require the outlet to be directed away from the fuel tank or passenger compartment. A turndown tip can help reduce droning and keep the exhaust stream away from sensitive parts.

Step 5: Install the Actuator (Electric Models)

For electric cutouts, mount the actuator motor in a location that will not be exposed to excessive heat or road debris. The actuator connects to the valve via a cable or rod. Follow the kit instructions carefully to avoid binding. Route the wiring along the frame rails, using zip ties to secure it away from exhaust heat and moving parts. Pass the control wires through a grommet in the firewall into the cabin.

Step 6: Electrical Connection

Connect the cutout’s wiring to a 12V power source. A fuse tap into an accessory circuit (such as the cigarette lighter or radio) is common. The ground wire must be securely connected to chassis metal. Test the operation: the valve should open and close fully when the switch or remote is activated. Adjust the cable tension if the valve does not close completely.

Step 7: Test for Leaks

Start the engine and listen for exhaust leaks at all connections. Spray soapy water on welds and joints while the engine is running; bubbles will indicate a leak. Tighten clamps or reweld as necessary. Exhaust leaks can cause fumes to enter the cabin and rob the engine of performance.

Fine-Tuning Your Vehicle’s Sound

Exhaust cutouts give you control, but the sound you get depends on several factors. Here is how to optimize your setup for car shows.

Choose the Right Muffler

The muffler you bypass determines the baseline quiet sound. A chambered muffler (like a Flowmaster) will have a distinct tone, while a straight-through design (like a Magnaflow) is quieter at idle but louder under load. Pairing cutouts with a free-flowing performance muffler ensures that when the cutout is closed, you still get a pleasant note for street driving.

Consider Dual Cutouts

For V-shaped engines, installing a cutout on each bank creates a more balanced exhaust note when open. Dual cutouts also allow you to open only one side for a unique sound. Some enthusiasts use a single cutout on a crossover pipe to blend both sides, but dual cutouts provide more flexibility.

Play with Outlet Length and Diameter

The length of the pipe after the cutout affects sound pitch. A short dump pipe (just a few inches) produces a sharp, aggressive tone. A longer extension pipe (2–3 feet) adds a deeper resonance. Increasing outlet diameter from, say, 2.5 to 3 inches will make the sound louder and more boomy. Experiment with different tips or lengths between events to dial in your preferred character.

Timing Activation

At a car show, the timing of opening the cutout can enhance the theatrics. Open the valve just as you blip the throttle to create a sudden bark that draws attention. For a cruise-in, keep it closed while idling in line, then open momentarily as you pull into your spot. Practice with the remote or switch so the motion becomes second nature.

Car Show Strategies with Exhaust Cutouts

Using cutouts effectively can separate your vehicle from the crowd. Here are proven techniques from show veterans.

The Grand Entrance

When you arrive at the show, keep the cutout closed to maintain a low profile. As you approach the main entrance or the designated revving area, open the cutout and give the engine a few sharp revs. This announces your presence without being obnoxious. Close the cutout as you park to keep the noise level down for the judges and spectators.

Demonstration Sessions

Many car shows have designated times for engine revving or driving demonstrations. Use your cutout to deliver a dramatic increase in volume during these moments. If the show allows, rev the engine in increments—partial revs with the cutout closed, then full revs with it open—to show off the versatility. The contrast between quiet and loud will impress onlookers.

Sound Clips and Video

Set up a camera to record your exhaust demonstration with the cutout opening and closing. Share these clips on social media with a link to your car build. Cutouts are visually interesting too: the moving valve mechanism can be a conversation starter when you pop the hood or direct attention to the undercarriage display.

Subtle Use During Judging

During static judging, keep the cutout closed. The noise can distract judges and irritate nearby exhibitors. Once judging is complete, you can open it for a minute and show off the sound, but always be considerate of the environment. Some shows have noise curfews or specific quiet hours.

Exhaust cutouts can push your vehicle outside legal noise limits. It is your responsibility to understand the laws in your area before modifying your exhaust.

Noise Ordinances

Most states have statutes that prohibit excessive noise from motor vehicles. The maximum allowable decibel level varies. Some states use a “plainly audible” standard, while others have specific dB limits at a given distance or RPM. Using cutouts on public roads may be illegal, even at shows that are held on public property. Check with your local Department of Motor Vehicles or the show organizer for guidance. At private venues, the rules are often more relaxed, but respect neighbors and community standards.

Exhaust Fumes and Safety

When the cutout is open and the outlet is under the car, exhaust gases can pool under the vehicle. If the vehicle is stationary with the engine running (common at shows), carbon monoxide can enter the cabin through open windows or the HVAC system. Install a carbon monoxide detector in the interior if you plan to idle for long periods with the cutout open. Position the outlet to point away from the sides and rear of the car.

Visual and Mechanical Inspection

Some states inspect exhaust systems for emissions equipment tampering. A cutout that bypasses a catalytic converter is illegal in jurisdictions that require functioning cats. You must ensure the cutout is installed after all emissions control devices (i.e., after the cat) or have a way to prove that the cat is not affected. Many cutout kits are designed to fit after the converter, making them street-legal in sound but still possibly subject to noise laws.

Insurance Implications

Modifications that increase noise or change emissions could affect your insurance policy. Check with your insurer whether exhaust cutouts are considered a high-risk modification. Some companies require disclosure, and failure to do so could void coverage in an accident. Always declare any major aftermarket parts.

To help you choose a cutout, here are some reputable manufacturers known for quality and performance.

  • DMH Performance: Known for their robust electric cutouts and lifetime warranty. Their low-profile motor design is popular on modern muscle cars. Visit DMH Performance
  • Quick Time Performance: Offers electric cutout solutions with remote control. Their QTEC systems are widely used in racing and show cars. Explore Quick Time
  • Summit Racing: Carries a wide variety of cutouts from many brands. Their in-house brand offers affordable options for beginners. Shop Summit Racing
  • MagnaFlow: Known for premium exhaust components, includes cutout-equipped mufflers and universal cutout kits. See MagnaFlow
  • Flowmaster: Offers cutout valves that integrate with their exhaust systems, ensuring a consistent tone. Check Flowmaster

When selecting a brand, pay attention to the material (stainless steel is best for longevity), the actuator type (electric with remote is most convenient for shows), and the size compatibility with your existing exhaust pipe diameter (commonly 2.5 or 3 inches).

Maintenance and Longevity

Exhaust cutouts operate in a harsh environment: high heat, moisture, road salt, and vibration. Routine maintenance ensures they keep working reliably for years.

  • Lubricate the valve mechanism: Use high-temperature anti-seize compound on the valve shaft and linkage every 3,000 miles or after exposure to rain. Avoid WD-40, which evaporates quickly.
  • Check electrical connections: For electric cutouts, inspect wiring for fraying or corrosion at least once a year. Clean fuse contacts and apply dielectric grease to connectors.
  • Listen for rattles: A loose cutout valve can create a metallic rattle at idle. Tighten mounting bolts and check the actuator bracket.
  • Inspect gaskets and seals: The flanges between the cutout and the exhaust pipe can develop leaks over time. Replace gaskets if you hear a hissing sound when the cutout is closed.
  • Exercise the valve monthly: Try opening and closing the cutout at least once a month, even in winter, to prevent the valve from sticking due to carbon buildup.

Cost Considerations

The price of an exhaust cutout system varies widely based on type and brand.

  • Manual cutout: $20–$100 for the valve and pipe, plus installation labor if you do not weld yourself.
  • Electric cutout: $150–$400 for a complete kit with remote and wiring.
  • Premium electronic cutout: $500–$1,000 for features like stainless steel construction, smartphone control, and proportional opening.
  • Installation labor: $100–$300 if you hire a muffler shop (welding and wiring).

While a basic manual cutout is budget-friendly, the convenience and showmanship of an electric or electronic cutout often justify the extra cost for car show enthusiasts. Many owners say the ability to instantly go from quiet to loud is worth every penny when it comes to crowd reaction.

Endnote

Exhaust cutouts are a versatile modification that can dramatically elevate your car show experience. They provide a controlled method to switch between a street-friendly exhaust note and an attention-grabbing roar. By choosing the right type, installing it properly, and using strategic timing during events, you can safely enhance your vehicle’s presence. Always stay informed about local laws and perform routine maintenance to keep the system working at its best. Whether you are a longtime show veteran or a first-time exhibitor, a well-integrated cutout system is a surefire way to make your car stand out.