The Perfect Platform

Moving bodies within the Earth atmosphere creat unequal air pressures. Because gravity pulls everything downward, air pressure beneath an object in motion gets compressed and denser than the pressure aboves it. The faster the object moves, the greater the pressure imbalance. So as it moves "forward", the space it vacates becomes a vacuum, void of air. This affect forces denser air beneath to move up thus pushing the rear end of the object to raise up. In car talk, the lifting rear end reduces friction between the tires and the ground. This fact of nature is a dynamic obstacle every fast car engineer has to face. It's a struggle between form and function, beauty or the beast.

Modern fast cars nowadays utilize one or more forms of mechanical contraptions to reduce the lifting of the rear end by adding a wing or extend the roof line further to the back of the car. Both methods offer a bandaid solution to the dynamic problem but at the expense of curb appeals. Cars are more bubbly. Symmetry and proportion are less pronounce. Plainly put, new cars offer less and less of the visual Q's and I'm sure many out there sees through the same glasses I have on. Now let's not throw away our eye ware and walk blind yet. Ferrari solved (reduced) the affect of this dynamic problem years ago. It combines form and function, maintain symmetry and proportion. It doesn't have a wing. It doesn't need to. It's roofline doesn't have to extend to the back. It doesn't have to. The engine bay is not sealed. Air pressure build up beneath the car exits through the engine bay. Uplift of the rear end dramatically reduced. Yes folks, I am talking about the 355's. The most perfect racing platform. I will further add, the 355's platform isn't utilized to its maximum potential. Had the engine came out the factory with additional 100 horses, it would be the 800 pound guerrilla of the racing circuit today. Nevertheless she is a beauty not afraid to run in high heels.

 

Dr. JohnK, what am I wrong about? The spoiler attached to the front bumper of a ground effect kit does work. It minimizes the space between the car and ground. Less space, less air underneath. In term reduces the lifting action. The side skirts don't really do jack. Only for cosmetic purposes.

 

A minute ago I thought I knew everything

 

maybe this help explains it

The Earth projects a gravitational pull on all things we see and can not see. The force of gravity gets weaker the father aware from the Earth core objects are. The size (mass) of objects also weight in. That is why the moon, much much bigger than a man is confined to an orbit around earth and an astronaut floating next to it can fly away into outer space if he chooses to. With that in mind, let's get back to Earth.

Air has no shape or size but it does have weight. At sea level air is densest at one atmospheric pressure. That's not a lot of weight at all standing still. If we starts running we can feel its weight pushing against our face. Now if we get into a car and move at 65 mph and stick our heads out (be careful of on coming traffic), we can really feel the weight of air pushing. But what's really going on? Dr. JohnK, every time you jump into your 355 and speed away listening to your favorite 60's era music and only slow down enough so you can eye the cute redhead you just drove pass, there's lot more happening than just the though floating in your mind. As you move forward, you and the car displace air. Below the bumper, air forces down beneath. The windshield pushes air to go up over the roof. It's easier for air to go up for 2 reasons; air is less dense above and there plenty of space to go. Where the roof ends, as the car moves further forward, there is a void of air. (This is where form, function and dynamic become a trade off in automotive design). Air below pushes up to fill the void. Air above pulls down. In physics, every action has an equal opposite reaction. The amount of force that pushes the air down to fill the void, is the same amount of force pulling the back of the car up. The key component here is speed. The faster the car moves, the greater the force. If a car is accelerating let say at one 9.8 m/s*2 (one G), it won't be able to turn and maintain control without external dynamic control.

The shape of sport cars is inherently its Achilles heel. The best proportioned design is also it's problem. The steep drop of the roof right above the trunk, the void. Some design eliminates the drop like the Ferrari gtc4lusso but it screfices beauty. The Porsche 911's has the worse design. The car shaped (side view) like an airplane wing requiring another massive counter wing in the back to keep it from flying away. Don't bother entering them in a beauty contest.

 

Rifle are you serious? I'm sure someone here can throw a set of wheel and strap a jet engine on a log and have it go 800 mph in a straight line. Im not impressed. There is no point. It's a matter of bigger engine. It's irrelevant to the subject matter. I'm talking about a street legal race car that is beautiful to look at and belong in the super sport car category. My argument is that the 355's has the best platform for speed and control in that it doesn't have eye sore contraptions like a wing to maintain control. Its flow through engine bay cools the engine and minimize the surface area thus reducing the lifting affect of its rear end so it stays planted on the road in high speed cornering. All successor models from the 360 to the 488, I will argue, do not offers better platforms. They just have bigger more powerful engine along with electronic stability aids. Again, if someone somehow can squeeze 100 horses out the the 355's, it's a beast on the track and a beauty on the boulevard.

 

Red, if you and dr. JohnK go skinny-dipping in a cave below sea level then yes air is more dense down there. For the purpose of calculating equations involving air and gravity, sea level is the reference point. Ofcourse you knew that

P.S. Don't forget to rise slowly

 

Lol this thread is becoming more amusing by the day. Steve C, think about it. Right now im itching to hear what dr. JohnK has to say LoL