Similar premise to removing the turbo silencer, this is a free modification which is a good DIY mod to get you started and will cut the small amount of disruption the lips cause to the flow of air to the engine...

The throttle body transition casting is located at the top of the turbo delivery pipe (from the intercooler to the throttle body). Due to the way it is machined and manufactured there are two 'lips' that when removed will help the flow of air to the engine without any disruptions.

1. Remove the throttle body casting and cover the throttle body with clingfilm or a cloth to stop debris from entering.

2. Once removed from the engine take off the o-ring and sensor from the casting.

3. Place the casting in a Workmate to hold steady and using a dremel fitted with a drum sanding head of medium grit, sand the lips from the top and bottom of the casting.

4. Once the lips have been removed and the casting is smooth, thoroughly clean the casting and dry with a clean cloth.

5. Reinstall the o-ring and sensor.

6. Refit to car and enjoy your work!