For you Aerodynamicists

[kbentzel]

After I made a few high speed runs at Carrabelle an interesting pattern of dirt appeared. Two vertical lines about 3/4 of an inch wide showed up. One just behind the front tires and one just aft of the rears. Another round patch developed just in front of the side vents. The pattern was consistent on both sides of the car.

Keith

[glennl]

The lines are where you are getting flow separation from the surface.

[Fezzek]

Originally Posted by glennl

The lines are where you are getting flow separation from the surface.

What does that translate into?

Martin

[REV2XS]

I'm no expert, but i believe this can cause drag.

Originally Posted by Fezzek

What does that translate into?

Martin

[kwmike]

Dust

[carbon fiber]

he is saying the air is leaving the surface of the cars body and is creating turbulence where you are seeing the dust left behind. when turbulence is created the air swirls and the dust is collected in these areas.

[CHOTIS BILL]

To see what the air is doing over the entire car I have sprayed a light mist of WD-40 over the car and then made some high speed runs. Sometimes it takes a while for dust to settle on the car but when it does you can get a pretty good idea of how the air is flowing around the car. Sometimes a part at the front of the car will affect the air all the way in the back. Things like changing the position of the side view mirror can either help or hurt the air going to the rear wing.

Bill Lomenick

[sk7500]

Wow! I always thought a dust pattern like that meant it was time to wash the car.

[buddyd]

The lines just behind the front and rear wheels are due to a break in air flow due to the wheel openings and the turbulence created by the rotating wheels at high speed. to lessen these two locations you would have to close up the opening between the tire/wheel and body opening which would increase the chance of wheel rub, also wuold need a wheel that disturbs less air ( flat on face like a salflats speed car ) not very appealing or practical. The area just behind the door is because of the side scoops built into the quarter panels, the opening into the scoop is not as large as the begining of the scoop. The scoop closes up from the bottom and at high speeds draws more air than can enter the scoop opening and creates a small venture effect. The size and locations of the dust markings are at locations and sizes that I would not worry about them unless you plan on competeing professionally, there is not enough of drag created by these markins two justify the expense, Besides you have a great looking car that needs nothing to change the looks at all.

[iron.man]

1700bhp Ford GT sets world record - BBC Top Gear

Now Im not the smartest person in the world... but it would seem the GTM would have the most similar shape to this car than alot of other cars other than the nose is a little lower and the back is a little longer... so if it can run dang near 300 without a hiccup .......................................