I wouldn't be so sure. You are making a hole with more than 5 times the volume where there wasn't one before. I can't see that having no effect. The path of least resistance and all. No, I would want to test what happens since you are using the same pump with the same pump characteristics but asking it to move way more volume through a much bigger tube. Since a bypass system notoriously moves about 12%, adding a much larger opening HAS to reduce that number.
I would offer to do an experiment, but I am sorta busy these days with other things. Maybe someone else could?
