Your straw analogy is flawed, this being due to the fact that your knowledge of fluid dynamics is limited to drinking thickshakes at McDonalds.
Your "crimping" experiments would hold validity for water, which, once again if you had studied fluid dynamics, you would know is vitrually incompressible, so yes, the maximum mass flow will be restricted to maximum velocity at the the smallest diameter.
The only problem with this analogy is that exhaust "gases" are VERY compressible, hence flow restrictions reduce mass flow at the point of the restriction, but DO NOT limit mass flow. Hence the more restrictive part of a flow regime does not control the maximum flow in a gaseous, compressible system and restrictions become additive. This is Bernouli's Law.
Stick to your law books and don't attempt to argue points that try to reverse the laws of physics, in order to boost your self perceieved ego and standing in this internet community. Alchemy may have been believed in the 14th century, but not here.
I've tried to remain civil in this argument, but I can only take pig-headedness for so long.
