Joined
·
3,656 Posts
That is because you are exhaling into an open environment. With the turbo neck though its still a closed environment so the losses are very little in comparison.Good point. Its gotta provide enough pressure to spool the turbo. Think about this: hold a pinwheel in front of your face and take a deep breath. If you exhale with your mouth wide open, pinwheel does nothing. You just open it a bit and exhale, pinwheel spins.
Opening up the exhaust port will help with flow on the top end. It will decrease velocity slightly until it necks down into the turbo but I don't imagine it will have that much effect on spool as compared to moving to a larger turbo would.