Turbosmart 97-06 Audi A4 1.8T 20V / 99-03 Audi S3 1.8T 20V Kompact Plumb Back Diverter Valve (25mm)

If you're looking to manage boost pressure on your Audi A4 1.8T 20V, this Turbosmart Kompact Plumb Back Diverter Valve is a solid option. This valve is designed to recirculate all excess boost pressure back into the intake system. This means you get the performance benefits of a diverter valve – like protecting your turbo from over-pressurization – without the noticeable 'pssh' sound you get from vent-to-atmosphere valves. It's a good choice if you want that improved turbo response and reliability without drawing extra attention.

The Kompact Plumb Back is a well-built unit from Turbosmart, a company known for its forced induction components. It features a 25mm connection size, which is common on many factory turbo setups. Because it's a full recirculating design, it's generally easier to install and less likely to cause issues with engine management systems that are calibrated for factory bypass valves. This valve is designed to fit right into many popular 1.8T 20V applications, offering a straightforward way to upgrade your turbo system's performance and longevity.