Granatelli 4" Electric Exhaust Cutout Kit, Stainless Steel Slip-Fit – 302540

Granatelli 4.0″ Round Electronic Exhaust Cutout Kit

SKU: 302540

Take total control of your vehicle’s exhaust tone and flow with the Granatelli 4.0″ Round Electronic Cutout Kit. Designed for high-output builds, this all-in-one system gives you the freedom to run quiet when needed—or rip wide open at the push of a button. Built for those who demand serious performance and bulletproof reliability.

One-Touch Smart Control

• Precision CNC-machined 6061 aircraft-grade aluminum housing delivers strength without the weight.
• High-torque Smart-Chip DC motor provides smooth, responsive actuation with auto-stop to prevent gear strain or overtravel.

Massive Flow. Deep, Aggressive Sound.

• Built for 4.0″ (102 mm) exhaust systems—the Round-profile butterfly valve ensures minimal restriction and full flow when opened.
• Includes a 45° polished stainless turndown and Round-to-round adapter, secured with 360° V-band clamps for clockable fitment.

Everything You Need, Right in the Box

• Complete install kit: turndown pipe, adapter, V-bands, gaskets, switch, wiring harness, and hardware—no missing pieces, no guesswork.

Engineered to Take Abuse

• Corrosion-resistant stainless butterfly valve and shafts stand up to the elements and extreme temps.
• A heat-rated carbon-steel gear train is built for high-cycle operation, even under full-load punishment.

Why It Dominates

• Flip the switch for stealth mode or wide-open roar—perfect for the street, track, or show.
• Heavy-duty construction resists wear and abuse from daily driving or hardcore runs.
• Designed for straightforward installation—ideal for pro shops or seasoned DIY builders.

Technical Summary

Bottom Line

The Granatelli 4.0″ Round Electronic Exhaust Cutout Kit – Part #302540 – is built for those who demand full authority over their exhaust. Whether you’re chasing horsepower, turning heads, or just want that deep growl on demand, this is the kit that delivers—no compromises, no excuses.

Sizing & Fitment

Measure the outside diameter of your exhaust pipe at the mounting point. If it measures 4", this kit is the right match. Running a true dual exhaust? Use one cutout per side, or choose the dual 302540K kit. Want a permanent, leak-free install? See the 307540 weld-in version.

Where to Mount It

Mount the cutout at least 18 to 24 inches after the catalytic converters, and away from any O2 sensor. Aim the turndown toward the rocker panel, away from fuel and brake lines. For the best sound, mount it after the X-pipe or H-pipe.

Legal Note

Many states, including California, prohibit exhaust cutouts on vehicles driven on public roads. Keep the cutout closed on the street and open it only at sanctioned off-highway events. Never install a cutout upstream of a catalytic converter.

Frequently Asked Questions

Do I have to hold the switch?
No. The Smart-Chip one-touch rocker completes the valve's travel with one tap.

Can I install it myself?
Yes. This kit clamps onto the pipe, so most installs need only basic hand tools and a way to cut the pipe.

What's the warranty?
90 days, with optional 1-, 2- or 3-year extended coverage available at checkout.

Will it add horsepower?
Opening the cutout reduces backpressure. Gains depend on your engine, headers and tune.

New to cutouts? Read our 4 Inch Exhaust Cutout Guide for choosing the right size and type, mounting and state laws.