The Bully Dog 85203 Ceramic Coated Exhaust Manifold provides an upgrade to the old stock manifold on your 2004-2010 CAT C-15 Acert. The Bully Dog Heavy Duty Exhaust Manifold features a high-flowing design that provides quicker turbo spool, higher power output and more fuel economy for class 8 engines. Bully Dogs engineering team has spent considerable time analyzing and flow testing various layouts for each manifold utilizing state of the art CAD design software.Â Each manifold is simulated and prototyped numerous times as they search for the design that produces the ultimate efficiency. There are two primary goals they are striving for in the design: first, to maximize the airflow by smoothing out the sharp corners of the stock manifolds and eliminating any bottlenecks in the design and second, to eliminate any known failure points in the stock manifold. The final result is an impressive piece that not only looks great but is fine-tuned in every aspect to improve the performance of the engine. Increased Airflow The sharp corners common on the stock manifolds have been eliminated along with other improvements to increase airflow. More airflow equals greater turbo response and an increase in horsepower to the rear wheels. Independent testing on a flow bench shows 18% greater airflow over the stock manifolds. Better Design The tolerance of these three-piece systems has been tightened to prevent leakage at the joints. A special metal alloy has also been used that is superior to the stock manifolds, so that all three pieces expand and contract at the same rate as the engine heats up and cools down over the life of the manifold. Reinforced Design Bully Dog didnt skimp on the material in the design. These premium manifolds are thicker all the way through to prevent cracking. The thicker manifolds combined with the reduction in heat from the ceramic coating has also proven to help lengthen the life of the gaskets. The end result is a better quality casting. Ported and Polished Each manifold is ported and polished once it is received from the foundry. This is done to ensure that no metal burrs interfere with the airflow that robs both horsepower and economy. Ceramic Coated The manifolds havent just been ceramic coated to make them look better. The ceramic coating both inside and out ensures that heat generated by the engine is more fully utilized to spin the turbo. The less the metal absorbs the heat, the greater the turbo response and the more efficient the engine. These ceramic coated exhaust systems not only reduce the radiating temperatures coming off of the manifold by 300, they also reduce exhaust gas temperatures (EGTs) by 80 to 100. This exhaust manifold replaces OEM Part# 231-6127. Please confirm OE manifold number before ordering to ensure proper fitment.Â Features: Reduced EGTs Up to 30HP Increase Ceramic Coated FinishÂ Improved Engine Efficiency 18% More Airflow Over StockÂ Reduced Radiating Temperatures Ported Design - Eliminates Flow Interference Caterpillar Applications: 2005-2010 15.2L CAT C-15 Acert Not available for sale in the state of California Click here to read Emissions Notice.