4"/5" Downpipe Back for 2001-2007 LB7 LLY LBZ 6.6 Duramax Race Exhaust

2001-2007 LB7 LLY LBZ Duramax 4"/5" Downpipe Back Race Exhaust 6.6 Duramax

Take your 2001-2004 LB7, 2004-2005 LLY and 2006-2007 LBZ Duramax diesel one step further with our downpipe back race exhaust. This pipe replaces the OE exhaust from the downpipe back to reduce restriction and improve exhaust flow. The 5'' diameter pipe helps lower backpressure, supporting better turbo response and more consistent power delivery. For off-road and race use only.

Key Features

• 4-Inch High-Velocity Flow: Replaces the aging, narrow 3-inch factory piping with a high-volume 4-inch straight path, drastically reducing exhaust backpressure.
• Massive Reduction in EGTs: Crucial for modified LB7s; dumping hot exhaust gases faster protects your turbocharger, pistons, and head gaskets from heat-related thermal fatigue under heavy hauling.
• Quicker Turbo Spool-Up: Removing downstream restrictions allows your factory or aftermarket turbocharger to spool up significantly faster, curing low-end lag and sharpening your throttle response.
• Unleash the Duramax V8 Rumble: Delivers a deep, aggressive, and unmistakable V8 diesel growl that the LB7 is known for, without the excessive cabin resonance found in poorly designed systems.
• Optimized Engine Efficiency: Allowing the engine to pump out waste gases with zero resistance translates to better engine efficiency and improved overall performance during towing.
• Industrial Mandrel-Bent Steel: Features smooth, unwrinkled curves throughout the entire line to guarantee zero neck-down or restriction points, preserving high exhaust velocity.

Technical Specifications

This race exhaust kit is available in 4-inch or 5-inch diameter options, and is made of T-409 stainless steel to provide durability for daily driving and rough long haul conditions. With a 2mm thick wall, this kit is designed to handle high heat and rugged use without breaking a sweat. T-409 has a slight magnetic property.

This kit includes band clamps, hangers, and all required installation hardware. It is designed for off-road or race use only, with no sensor bungs included.

5-inch system allows more airflow and is louder than the 4-inch pipe; a muffler can be added if reduced exhaust noise is preferred. (Available in bundle product)

Installation

You need to pair it with race tuning for peak performance (available in bundle product). The package includes all essential clamps and hardware for a bolt-on installation with basic tools. For optimal outcomes, professional installation is advised.

Shipping & Returns

Fast & Free Shipping Policy

Your order will be dispatched within 1-2 business days, and the package will arrive within your order's estimated date. Click for Shipping Policy.

Easy & Free Return Policy

Every order comes with a 14-day free return, which means you don't have to pay for a return slip. Click for Return Policy.

Fitment

2001-2007 Chevrolet Silverado / GMC Sierra 6.6L Duramax LB7 LLY LBZ 2500HD 3500HD

*Does not fit Cab & Chassis trucks.

FAQs

Q: What does "DP-back/Downpipe-back" mean?
A: This means the exhaust system will replace the OE exhaust from the downpipe all the way to the end of the exhaust pip. This typically includes the mid-pipe, catalytic converter (if present), and muffler.

Q: What is your race exhaust made from? Stainless steel or aluminum?
A: They are made of 409 stainless steel.

Q: Does your race exhaust kit need me to purchase additional parts?
A: Our exhaust kit comes with all the parts. Normally, there is no need to purchase anything else.

Q: Does your Dp-back pipe work with stock parts?
A: Yes, our DP-back pipe can fit perfectly with the stock Downpipe and stock bolts.

Q: Will this exhaust fit cab and chassis models?
A: No. The Cab & Chassis has a relatively longer chassis and requires a tube specifically designed to fit the Cab & Chassis model. For further assistance, please reach out to our customer service.