1:1 intake to exit area can be enough, I would like to see more of your exit area before commenting, too many people concern themselves over what goes in. Exit is far more important - create the right low pressure by installing louvres and the air will move through and cool the engine.once you have airflow then directing it in the right places works even better, but trying to direct it when there is no pressure difference is also not going to do anything. Louvres creating low pressures work extremely well around the cowl as these are in the best airflow (propwash) when the plane is stationary or in 3D, they will continue to draw the airthrough the cowl....