Most manifolds have the wastegate positioned below the turbo on the exhaust manifold itself ,was wondering if you were too drill the turbine housing and weld a flange onto it and then mount the waste gate on to the turbine housing,what would be the difference with controlling your wastegate as compared to the normal way on the exhaust manifold.

 

I'm not sure about this but I think most exhaust housings are cast iron, and I don't think you can really weld cast iron. You can braize (sp) it, but this would not stand up to the heat. I'm not 100% sure about that if someone knows different please let me know.
Nick

 

You have to interrupt exhaust flow BEFORE the turbine to be succesful at controlling booost.