RS5 (B9)

Lowering springs are one of the most popular first changes, closing the arch gap and reducing body roll while keeping a usable ride. Owners then often add a front splitter, side skirts and paddle shifters. For performance, a Stage 1 remap of the 2.9 TFSI with matching gearbox software is a common next step, along with turbo heat protection and fresh brake fluid for track use.

It depends on the kit. Depending on specification, RS5 B9s have RS sport suspension or RS sport suspension plus with Dynamic Ride Control (DRC), which links diagonally opposite dampers hydraulically to reduce roll. Spring and coilover kits are often specific to one setup, so check that the listing matches your car before ordering. Coilovers such as AST are a popular alternative when DRC dampers are worn.

Mechanical parts such as springs, coilovers, filters and heat protection are generally shared, because the 2.9 TFSI and drivetrain carried over unchanged. The late-2019 facelift revised the front and rear styling, so splitters, diffusers and some bumper-mounted parts may be specific to one version, and Coupé and Sportback bodies also differ at the rear. Every R44 listing shows the year range and body style it fits.

It is not essential for every tune, but it is commonly recommended. The RS5's eight-speed tiptronic is a torque-converter automatic that generally handles tuned torque well, and TCU software can raise torque limits, sharpen shift speed and improve response in manual mode. Ask your tuner whether their engine calibration is designed to be paired with gearbox software, and service the gearbox fluid regularly.

The 2.9 TFSI is a hot-vee engine, with both turbochargers mounted between the cylinder banks. This improves response but concentrates heat on top of the engine, close to hoses, wiring and plastic components. Turbo blankets, heat sleeves and exhaust wrap reduce radiant heat in the engine bay, which helps protect those parts over time, especially on tuned cars or after hard track sessions.

Yes, provided it is healthy. The 2.9 TFSI is also used in Porsche models such as the Panamera 4S and is generally robust, but tuning raises heat and stress. Check the service history and known EA839 family issues such as water pump leaks and PCV valve faults first, keep oil and coolant fresh, and use quality fuel. Declare any modifications to your insurer in the UK.