Our ever patient deskside companion "Websters Collegiate Dictionary"  defines the word "Dynamics"  as "a branch of mechanics that deals with forces and their relation to motion"...Hmmm...Yea man, I really dig this word and how it so beautifully fits our land speed record efforts. We are designing a vehicle to STRAIN against the physical limitations of forces that we have little control over. The laws of physics cannot be denied. I gues that's why we call it "pushing the envelope"... So why is it so important for us try to overcome them??? We as humans have somwhere along the line been given a spirit that will NOT be denied some sense of accomplishment... It's a good thing that we don't all pursue the same goals - for instance, if it was up to me to figure out how to pasturize milk, we'd all be sitting on johns with a bad case of "the scoots"...Err,Well, you get the picture... What brought this discourse on was a discussion that I had with one of my colleagues over the fact that we live in a very dynamic world and virtually nothing is "static' ever. You see, he had pointed out to me that I had made a "gross" simplification (noted) in my previous columns about the air we are passing through as "static" which would be almost NEVER!...DUH!...The very earth we are standing on or traveling along is moving at 1098 miles an hour! (at the equator). HOLY SMOKES!!!! This thought is so freaking cool that I'll never feel like a couch potato again! I'll have to set on the north or south pole to be REALLY static. Uhhh, wait a minute... At some point I suppose that I will have to get up off my ass and try to accomplish something or else I'll be denying my spirit...Darn-it! Note; I'm going to break away from our current Enfield Bullet partial streamlined project and address our design of a real live STREAMLINER that Dan and I have been playing with... Don't worry, the B'ville bullet will return as soon as it arrives in our shop from uncle Glen. I hear that he has it running and the NOS is installed...Stay tuned! Anyway, the air that we are trying to penetrate at great speed is really never static. It is virtually always traveling form a high pressure to a low pressure and has some energy to it that will affect our maximum speed efforts. All the calculations in the world can't tell us exactly how to manage it but we can design for a minumum disturbence of it. The air moves in different ways the further you get from the ground, but for our purposes we will be operating as close to it as we can safely provide for. Somewhere around 27 to 30 inches maximum height would be cool. A radicaly low frontal area should be way cool here, especialy in a crosswind situation but it carries with it other significant penalties in special tire diameters and super high bearing speeds. There is a noteable loss of stability when you loose the gyro effect of the wheels so for now, we will try to keep our shape as narrow as possible and stretch the rider out to set almost prone to fit in the widest part of the elipse when viewed from the front. We will suffer a slight height problem with our center of gravity but the overall advantage of our shape and total drag number should make up for it. Crosswinds are always a problem for streamliners as they disrupt the flow along the sides and make our single track motorcycles lean into them to compensate. This can lead to a drift that cannot be corrected and then we go sliding down the salt on the aluminum and not the rubber...End of fun! So at the surface, the air is rolling and tumbling along, (i.e. turbulent) and as we accelerate through it, we will be forcing it to flow around us in a manner that is as CONTROLLED as we can possibly manage. Our shape must be free of voids and abrupt changes in the surfaces so we can slip through it with very little wake turbulence. As you watch a land speed record attempt, you can pay attention to the "rooster tail" of dust that extends out behind the vehicle and see a graphic demonstration of wake turbulence. It's a shame that we can't see what is happening at the opposite end as some pressure is generated out ahead of our vehicle in the form of a bow wave or pressure turbulence. This is every bit as important to us and must also be managed through clever design. I have a theory that we must try to force the air OVER and AROUND and limit the amount that flows UNDER our vehicle. All kinds of nasty things happen to the air that passes beneath us and is basically un-manageable because of the physical limitations of our design. Our wheels (that we can't do without) will encounter the tortured air as it packs under the nose and becomes out of control turbulence. One wheel follows the other and...Well it just sucks down there! We MUST design for reducing this effect.  I'm a big fan of what I call a "ground plane splitter" that is used to create a more positive separation of the air that we allow to pass under the vehicle - kind of like a knife edge skimming along the surface to slice the air and reduce the volume allowed to pass underneath. It would protrude out along the extreme lower forward facing surfaces, with a bit of radii to blend it into the verticle sides. If you look at the latest racing prototype cars you'll see this broad flat panel that skims along the road at the front and sometimes down the sides. They are trying to make downforce in deference to the rules that mandate a "flat" bottom devoid of the "ground effect" tunnels that have been used to literally suck the car to the road. We don't want to make "down force" which would increase the drag but the seperation or positive split should help us reduce the turbulence under us. The splitter as it spans back along the length of the sides would also create a "vortex" and roll the split-off air out away from the sides in a more controlled fashion, thus reducing drag even further. If air molequeles are just dumped off the sides or allowed to collide with the ground in close proximity to our body a great deal of drag force is created and buffeting or eddies will disrupt the smooth flow of attached air. NOT a good thing! I suppose that I should explain a few of these words that I am using to describe what the air is doing as it passes over our streamlined body. A perpendicular roll or wave of air as it passes an abrupt surface change is called an "eddy" and is undesireable. It also promotes seperation of the air from the surface and has a heavy drag penalty when it occurs. Any gap in the body work can can create these. A "vortex" or mini horizontal tornado that swirls in an ever increasing radius is generated as the air flows over or accross a surface that makes an abrupt change but runs at an angle to the direction of travel. This has less than half of the drag penalty as an "eddy" depending the angle and height of the aforementioned angled surface. It also tends to stay attached to a body longer as it expands and travels the length of the surface. Usually a vortex is designed in to "help" a problem transition and prevent "uncontrolled" turbulance like in our "under vehicle" scenario mentioned above. The lessor of two evils kind of sums it up. A vortex can be generated in different ways depending on what you wish the air to do. Just look at the little diamond shaped posts that stand up from the top surface of some jet aircraft wings that are creating alot of little vortices that may enhance elevator or some other controll surface at various air speeds. They can be a very useful feature. Ok so we are accelerating through the air and trying to manage the turbulence and minimize the drag force with our cleverly designed shape...Now what other factors must we deal with???    Always Racing! Phil