Rev9Power Rev9_AC-055; 90 Degree Rotation Flange For 38mm Wastegate Product Details Project's 90 degree rotational flange for the 38mm wastegate 3/8" thick This flange allows you to rotate and mount the wastegate correctly if the flange is pointed the wrong way on the turbo manifold. This flange gives some additional flexibility on how to mount the 38mm wastegate when there's limited space in your engine compartment