Here's a little more to add.

Wastegate feed quality is extremely important for street cars that wish to run oversized compressors at low efficiency ranges.

A properly designed manifold should favor the wastegate no less than 40% or so, especially when used with a super-flowing engine combination, and a larger exhaust-side on the turbocharger.

Let's take a quick look at what happens when you design a manifold with a 90-degree sharp turn welded onto a collector





*Photos courtesy of Geoff @ Full-Race

As you can see, exhaust gases have the tendency to blow right by the wastegate entry, rather than bypass the turbine.

Now, as long as there is a larger amount of restriction in the exhaust housing, exhaust gas will "back up", so to speak, and be more inclined to evacuate through the path of least resistance, which in that case would be the wastegate.