F355 underbody panels = negative lift....

It is just the air that goes under the nose. Due to the shape of the tunnels it creates a slight low pressure area at the rear. Really requires a lot of speed to amount to much.

The fully sealed bottom of the 360 with its much larger tunnels created quite a bit more downforce.

 

look under the front bumper under the license plate..between the fog lamps...you will see the ridges on the underbody bodywork (about 30" apart).....directing the air underneath the car.

 

Short answer: "Race Car Aerodynamics: designing for speed"

When the underbody is free from things that slow the airflow under the car {Hint practically anything but a nice smooth plane slow the airflow},
A big nozzle in the rear (the diffuser panels) allows the airflow under the car to exit smoothly.
This high speed air has lower pressure than he atmospheric air on the top of the car, pushing it towards the road.
All of this air leaving the undersides of the car needs a point of resupply, thus the venturi at the from center of the grille.
With this resupply, there is a complete path from air in front of the car to air behinds the car with the property that the air under the car is of lower pressure than the air above the car.

That, in effect, is negative lift.

 

The 360 had much more down force and it had 180 kilos (396 lbs) at 280 kph (175 MPH).

If memory serves the 360 was the first production car to achieve negative lift, the 355 only managed to reduce lift. Aerodynamics of the 360 were so advanced at the time it was the subject of a paper for the SAE.

 

Race Tech 110 Underwing and Diffusers

 

That's what lift is.

 

F355 achieved negative lift, about 1/2 as much as the 360.

The thing that went negative on the 360 was the looks.

 

What does Rifledriver know anyway right?..

 

How true