Theres a hole in my manifold?!

A question we keep getting asked, “Is there supposed to be a hole in my manifold?”

The answer is yes… but only if you are referring to this hole.

When we build the collector, it is welded internally and externally, we then cut the wastegate port into it and again fully weld it. Once this is done we weld on the hexagonal brace to greatly increase the strength of the manifold. When this brace is installed it creates a cavity of air behind it. If there was no hole, the air contained would expand and contract as the manifold heats and cools fatiguing the area behind the brace and eventually leading to failure.