Ground Effects Measurements

[johnelliott24]

I am building a mid engined fun car and want to give it max downforce (no rules) so I plan to cover the whole bottom with an ideal shape and moveable side skirts. I did this with Lexan by "seat of the pants" on a 911 last year and definitely noticed the difference.

Does anyone have data on what dimensions are ideal for ground effects? I have read that the "draft" should be about 2cm off of the road and the difuser at 11 degrees max. (I'm sure the speed matters here). Any ideas on what the entry should be (flat slight or attack angle of how much)?

[johnnyperl]

how much power,weight,speed,etc...? the specifications of the bottom are highly dependant on the top of the vehicle post a picture of the car.

a flat bottom will reduce the Cd but wings will be eaisier and more adjustable for downforce.

did you "feel" a difference or did you measure a difference on the 911?

[PerfAdv]

Only someone with access to a wind tunnel can answer this question; once they've parked your car in the wind tunnel that is...

[maverickgoose]

Only when you subject your car to the Downward Windforce, u will be able to know exactly how you car behaves, so better subject it to WindTunnel Measurement.

[Cyco]

I'd try and find some pics/measurements/models of the ground effect F1 cars and use those as a starting point for installing points in a CFD program

[drakkie]

I'll get my German book out (Kraftfahrzeugtechnik Handbuch) and search for it. Give me a few minutes

Ok,if any gives me the grman translation for ground effekt i can search for it in the registry in the back ... I have no clue what it may be