fatbillybob

On another forum was a discussion about windows down aerodynamics of coupe converted street cars to race cars. Some ideas were to put holes in the lexan back window to vent air out of the cockpit parachute. I have seen this on some 911's. Some said "venting" the cockpit encourages air to flow into the cockpit thus increasing aero drag! Have any of you with 911's tried holes in the 911 back window and a unperforated back window to see what happens?

earlyapex

My plastic back window blew into the cockpit last year. It was over 100 degrees outside. The air flow through the cockpit was dramatically increased, which was a blessing given the conditions. My times did not suffer, but our tracks do not have very long straights where I imagine any aero drag changes would be felt.

analogmike

I pulled the door windows out of my cup car and was worried about aero (they are normally sealed, but it gets TOO HOT and nauseating in these watercooled cars). I was told that a cup car was tested with and without windows on a fast German track and there was almost no difference in lap times.