Thats certainly a good idea.
thing is fluid modelling is a compllicated expensive business.
The RT ones 'should' make a difference, but as far as I'm aware its not that they have been created in a cad lab and can scientifically demonstrate that they will increase airflow. If I'm wrong someone please correct me here.
(anyone used one on a dyno - thats where the proof is I guess?)
If you're just doing it by eye, there is no real guarantee that you're making a difference anyway.
As a one off, to do the modeling and create something thats a significant improvement will cost a lot more than the RT ones I think....
