BMW 3 Series316i(F30/F31)


De-Cat Downpipe (N13)

De-Cat Downpipe (N13)

In order to get even better efficiency for the section of exhaust turbine, as well as to prevent multiple welding positions in the downpipe section, which generates ash in the pipe while welding, causing bad exhaust efficiency, and then generates vaper lock and thus inability to exhaust, Stone Exhaust uses a variety of smart ideas in downpipe design. The company employs flow velocity measurement software in 3D and the technique of one-piece bend pipes, along with mechanical arms which accurately welds without generating ash in the pipe wall in order to further exhaust efficiency of De-Cat Downpipe. It is a perfect and effective product which has surpassed all similar products in the market.


1.SUS304 Stainless steel.

2.Computer simulation of the best diameter.

3.Integrated Curved Pipe Technology.

4. Dual Cross-Welding Technology Significantly Increase its Durability.


Designed for race track only, not recommend to use on a regular road.

Emission Notice

Other Products for 316i(F30/F31)

Eddy Catalytic Downpipe (N13)