4BT Cummins Manifolds
3.9L Cummins 4-Cylinder Manifold | 4BT Exhaust Upgrades
Diesel Power Source manifolds for the 3.9L Cummins 4-cylinder engine deliver strong airflow and reliability for industrial, off-road, and swap projects. Our precision-cast design improves boost control and turbo spool while resisting heat stress and cracking. Ideal for durable performance in compact diesel builds.
3.9L 4-Cylinder Cummins Exhaust Manifold FAQs
Upgrading the exhaust manifold on a 3.9L Cummins improves exhaust flow to the turbocharger, reduces drive pressure, and helps control EGTs under load. Performance manifolds also address cracking and sealing issues common with factory units, while supporting faster spool and more consistent boost on 4BT and other 3.9L applications.
The best manifold depends on turbo choice and intended use. Stock-location manifolds are ideal for compact swaps and daily-driven builds, while T3 and T4 manifolds support larger turbos, higher boost, and compound setups. Choosing the correct 3.9L Cummins manifold ensures proper turbo fitment, efficient airflow, and long-term reliability.
Yes. A properly designed 3.9L Cummins exhaust manifold improves turbo response and reduces exhaust restriction, resulting in cooler EGTs and smoother power delivery. These benefits are especially noticeable in towing, off-road, industrial, and engine-swap applications where the 4-cylinder Cummins operates under sustained load.
