I was just wondering how downforce levels compare between an F1 car and an LMP1 car.

I have limited knowledge on LMP1s, but I understand there is emphasis on 'ground affect' and underbody aero. Also I understand that as these cars are tuned to race at LeMans, low downforce is important and will reflect in their aero package. So how close are LMP1s to the downforce levels of F1 cars?