MagnaFlow Exhaust Performance Muffler 11229 4in x 9in Oval — Straight-Through, Deep Resonant Tone

MagnaFlow Performance Exhaust Muffler 11229 is a 4" x 9" oval, straight-through muffler engineered to deliver a deep, resonant exhaust tone while improving exhaust flow and durability.

This muffler is built for drivers who want the unmistakable MagnaFlow sound plus measurable flow improvements. Crafted with a straight-through perforated core and two-stage acoustic packing, the 11229 balances strong mid-to-low frequency tone with minimal airflow restriction. It’s a universal unit designed for flexible placement and orientation, and it comes backed by MagnaFlow’s limited lifetime construction warranty.

What sound and tone can I expect from this muffler?

The 11229 creates the deep, resonant note MagnaFlow is known for without excessive rasp. Its internal straight-through core and two-stage packing tune mid and low frequencies for a smooth, full-bodied exhaust character that works across many engine sizes and configurations.

• Deep, resonant low-end emphasis with controlled midrange.
• Reduced harshness compared with chambered designs.
• Consistent tone at idle, cruise, and under load.

How does this muffler affect performance?

MagnaFlow engineers dyno-test their designs to minimize backpressure and improve evacuation of exhaust gases. The 4" x 9" oval straight-through perforated core preserves exhaust velocity to support breathing, which can help maintain or slightly increase engine efficiency depending on the vehicle and complete system.

• Perforated core reduces restriction compared to packed chamber designs.
• Optimized flow dynamics for more efficient gas evacuation.
• Dyno-proven validation used during development.

Is the 11229 easy to fit to my vehicle?

The muffler uses a universal configuration so it can be oriented and located to suit many custom installations. While the shape and size support flexible placement, professional installation is recommended to ensure correct hangers, clearances, and welds for safe, long-term operation.

• Universal design supports custom routing and mounting options.
• 4" inlet/outlet sizing fits common exhaust piping with adapters.
• Professional installation advised for optimal fit and safety.

What materials, construction, and warranty does MagnaFlow provide?

The 11229 features resilient construction and a straight-through design with acoustic packing for lasting performance. MagnaFlow stands behind the build with a limited lifetime construction warranty, providing reassurance against manufacturing defects in materials or workmanship.

• Durable internal perforated core with two-stage acoustic packing.
• Proudly made in the USA to MagnaFlow specifications.
• Limited lifetime construction warranty included.

Who is this muffler for? If you want a bold, deep exhaust note with improved flow and a universal, adaptable muffler body, the MagnaFlow 11229 is a good match. It’s ideal for custom exhaust builders, performance-minded owners seeking a fuller tone without excessive rasp, and anyone replacing a worn muffler with a durable, dyno-tested MagnaFlow unit. For best results, have a qualified exhaust shop verify fitment, welding, and hanger placement to match your vehicle’s clearance and emissions needs.