If your manifold priority is good enough

3Caster: 3 +/-0

cost-effective external wastegate – The highest-flowing wastegate of its kind

for How to chose the Right Size External Wastegate

eSG50 Electronic StraightGate SL-01 If your manifold priority isThe StraightGate50 eSG50 from Turbosmart is a 50mm (1. 97in) butterfly valve style external wastegate for turbocharged engines. The StraightGate50 provides more flow than any conventional 60mm poppet style valve while also providing more control and almost linear response for unparalleled boost control throughout the entire operating range. This is Boost Control re imagined! Features 50mm (1. 97in) Butterfly Valve Full Electronic Control Liquid