PDI Big Boss Intake Manifold for Cummins ISX CM871 (2008–2010)

Part Number: 3684429
Engine Compatibility: Cummins ISX15 CM871 (2008–2010)
Warranty: 1-Year Unlimited Mileage Warranty

Unlock More Power & Cooler Temps for Your ISX CM871

Looking for a way to increase horsepower and airflow on your 2008–2010 Cummins ISX15 engine? The PDI Big Boss Intake Manifold is engineered to do exactly that—delivering more clean air to your engine, reducing intake temperatures, and improving overall performance and efficiency.

Factory intake manifolds are built for emissions compliance, not power. Their restrictive, “necked down” designs limit clean air flow and increase the proportion of exhaust gas recirculation (EGR). The Big Boss Intake reverses that trend by opening up the flow path and delivering up to 15% more clean air.

Key Performance Benefits

• Up to 15% increase in clean air intake volume
• Reduces intake air temperatures for cooler, denser combustion
• Provides an additional 15–20 horsepower gain
• Direct-fit installation using factory hardware and mount points
• Improves fuel economy and torque under load
• Designed and Made in the USA

Emissions Compliance Notice

NOT LEGAL FOR SALE OR USE IN CALIFORNIA or other states that follow CARB emission standards.

OEM Cross Reference

OEM Reference Number: 3684429

Easy Installation

This intake manifold is designed for a drop-in fitment. It mounts in the factory position and uses OEM hardware, making installation simple with no fabrication required.

Frequently Asked Questions (FAQs)

How much horsepower does this intake manifold add?

You can expect an average gain of 15–20 horsepower and improved fuel economy due to enhanced combustion efficiency.

Is this intake manifold emissions compliant?

No. This product is not legal for sale or use in California or any CARB-regulated state.

Is the PDI Big Boss Intake a direct fit?

Yes, it fits directly into the OEM location for 2008–2010 Cummins ISX CM871 engines using factory hardware. No modifications needed.

What improvements will I notice?

You’ll experience cooler intake temps, increased engine responsiveness, more efficient combustion, and a reduction in EGR-related performance loss.

What makes this better than the stock intake?

The factory intake is designed to meet emissions requirements but limits performance. This upgraded manifold eliminates restrictive areas to boost airflow and power.

Is this product made in the USA?

Yes. PDI manufactures all of its performance components, including this manifold, in the USA.