Scope of delivery: - Downpipe for Audi A4 A6 1.8T B5 3B 3BG Quattro ø 63.5mm 2.5" made of stainless steelProduct description: - The downpipe sits between the catalytic converter and exhaust system. It is bolted to the original catalytic converter, or our plug & play 200-cell catalytic converter with item no. 340106 can be used. It has a diameter of 63mm (original 54mm), an Interlook flex pipe, and brackets are installed. The larger downpipe reduces backpressure, relieves the turbo, and allows for more power, depending on the installed components, up to 330hp. The pipe is bent and is only welded at the flex piece and flange. To connect to the original exhaust system, a 63>54mm reducer sleeve must be used, but in most cases larger exhaust systems are used for tuning.Suitable for: - Audi A4 1.8T B5 (8E) Quattro 150-180hp - Audi A6 1.8T C5 (4B2,4B5) Quattro 150-180hp - and also for the following upgrade turbochargers: - Borgwarner K04-015 53049880015 - Borgwarner K04-015 / K06 - Borgwarner K04-015 / TFSI Compressor WheelRegistration: For individual approval according to §21 StVZO, please ask your TÜV inspector.Please note that the installation of this item constitutes a modification that invalidates the vehicle’s operating permit under the StVZO. Use in public road traffic is not permitted.