Originally Posted by
merkyworks
I'm surprised this would work as well as it does because the cutout for the motor should destroy any effect the diffuser creates.
You don't have to cut out the hole in the diffuser.
There are two ways of looking at it. Leaving the diffuser solid means you have a smoother airflow to the diffuser and faster moving air under the pod to reduce pressure and generate downforce. Cutting the hole out means you have the airflow wrapping around the bottom of the motor, pulling air up through the hole which reduces the air entering the diffuser, so reducing pressure again to generate downforce. The air coming up through the hole ends up going over the top surface of the diffuser, also helping downforce.
Personally I always cut out the hole, it helps airflow around the motor and running indoors on tight tracks means motor cooling is very much a priority.