An extensive amount of engineering time was poured into developing our GESi Catted 3" Downpipe to produce the best all around option on the market. Starting with the CAD designed investment-cast turbine outlet, made of 304 stainless steel for enduring corrosion resistance and reducing heat transfer to the engine bay. The bellmouth shape of the outlet flange makes optimal use of the tight confines of the Mazdaspeed3's engine bay, smoothly blending turbine outlet and wastegate gases. The outlet also contains two O2 sensor bungs to accomdate the stock O2 sensor and offer the option for additional sensor installation to suit each individuals needs. Further downstream comes the stainless steel flex section which is internally lined to protect the steel braiding while maintaining optimal exhaust flow. The placement of the flex section just before the first exhaust hanger is important as well. This minimizes the effects of engine movement on the cat, flanges, and remaining exhaust components. Plus, the use of the factory donut flange design allows for compatibility with any cat-back exhaust designed to work with the factory cat section. Installation of any aftermarket Mazdaspeed3 downpipe requires an upgraded Cam Shaft Driven Fuel Pump (CDFP) and tuning to ensure adequate fuel supply and safe engine performance.

Why?

The COBB 3" Downpipe is one of the key upgrades for the MAZDASPEED3 to unluck a huge amount of torque hidden away within the MZR 2.3 DISI Turbo engine from the factory. Considerable effort was spent designing a flow path with the fewest number of directional changes and minimal degrees of bend in order to eliminate restrictions that have been found in the stock system. This beautifully fabricated downpipe delivers significantly improved exhaust flow, resulting in faster turbo response time and power gains across the entire rev range.

Features