When installing a BOSCH 54mm DBW throttle body onto the MK3 Renault Sport Megane 250 265 275 F4RT engine there is a large flat edge/step on the intake manifold flange from the smaller inner diameter of the OEM throttle body. This plate helps to mitigate the loss of airspeed and to smooth out the transition of the port of the larger throttle body to the intake manifold thus reducing turbulence. The adapter is made out of 6mm 7075 aluminium and then anodized in matte black to protect against corrosion, the throttle body mounting side has a viton o-ring seal which can handle heat up to 200°C. In Renault's wisdom the hole port in the inlet manifold is not directly in the center and is offset, the adapter plate will only be correctly mounted in one location, please test fit first before mounting it all up to make sure the flange plate matches the intake manifold's port hole, the throttle body side port hole is in the center. For sealing of the adapter plate against the intake manifold you can use the OEM/Renault gasket or Permaseal Throttle Body Gasket Part # TB921 is a good option.
