These stainless steel made Alpha Competition decat downpipes, in 3.15" / 80mm diameter, fit without modification between the turbos and the front pipes of the S58 engines fitted to the BMW X3M / X4M F9x in order to remove the main catalysts. Manufactured from high quality T304 stainless steel with handmade TIG welds, these downpipes will bring an average gain of 35hp on a stage 1 engine and a particularly aggressive sound. With a high flow structure and thermal insulation (Optional) to reduce heat radiation by 50%, these downpipes clearly represent the best value for money on the market!

- Select your version -

Direct mounting

2-piece kit

100% T304 stainless steel

3.15" / 80mm pipes

Measured gain on stage 1: 35hp

Aggressive sound

Handmade TIG welds

Assembly kit included

Optional specific thermal insulation

Lifetime warranty

- ECU calibration is mandatory -