If it's after/during a restriction, isn't that going to cause a "high pressure" point for it?
Correct me if I'm wrong, but if you have a pipe, with something flowing through it, and you want something to be "drawn" or sucked into it, you would be better off putting an expansion in, because as the pipe expand, the gas flow slows down even though it would rather keep going, and as such puts a low pressure zone in...
Isn't this the same theory the carburettor runs on? Run the airflow in, as it goes through the carb, it expands in size, and this is the point fuel is drawn in at?