Facts, Physics and boring stuff

[600Catapilla]

Hello All
 
 Can u direct me to the physics and laws side of Land Racing, meaning what is working against you - wind, friction,forces etc?
 
 I have held a long interest in speed and am not a BookWorm but I would like to try to understand the physics involved before I attempt to build a diesel powered machine.
 
 If I am not on the right track, I should imagine I will soon be told.
 
 Many Thanks

[Bob Drury]

Here is a good law to ponder:  Only in LSR racing do you add weight to go faster................

[dwarner]

Rule two:
 
 At El Mirage you take out horsepower to go faster.

[StraightSix]

I like this page: http://www.teknett.com/pwp/drmayf/analyses.htm

[600Catapilla]

Ok you have my attention,
 
 Bob - How much weight is too much,or too little? Or is there ideal weight? Could u expand on your point?
 Or are you meaning that you can enter a higher category (adding more Power) because of more weight?
 I had a 2 stroke 185 Suzuki that was my only wheels when I started my apprentiship at 16, it would pull 4 mph faster with 2 people on board, than just with me onboard. Not that its top speed was worth mentioning, I must say!
 
 Dan - What is the relationship between Horsepower,Torque and overall speed? Is Torque the Tool that pushes you faster or is it a combination? Or r u suggesting a smaller engine with great torque is better than a monster with small torque?
 
 How does wheel slippage come into play.(Too much Horsepower) and how big a problem is it for LSRs?
 
 StraightSix - Many thanks for the link.I have bookmarked it and will read the articles.
 
 I appreciate your imput and please be patient with my replies due to time differences.
 
 Many Thanks

[Bob Drury]

Well, CatMan, If you plan on running that Roadtrain, Law #1 is out the window.  If you plan on running something a few tons lighter, you will find the faster you go, the less traction you have ( do to aero lift, amongst other things), and adding weight is not nearly as much of a handicap as aero drag.  The bottom line is, you gotta have traction to go fast, and with the Roadtrain, I forsee no problem with that particullar item.............

[John Burk]

Andrew
   In LSR there are three cases where adding weight helps .(1 To move the CG foreward to keep the car from spinning out .(2 To reduce wheel spin to make the car easier to drive .(3 To help punch through the air better with very fast cars . The first two add safety . The last adds speed .

[dwarner]

Wheel spin is a big problem. Racing on the dirt of El Mirage to go forward you must keep the tires under the car. Taking out HP will help to reduce wheel spin and keep forward movement increasing. The ideal is yet to be found as the records are continuing to climb. If the "end all" combination has been reached then the records would be the fastest they will ever be.
 
 Excellent article in the latest Hot Rod on how bore/stroke/rod length relationships effect HP and torque.
 
 The balance between HP, weight distribution and aero balance is foremost in LSR.

[600Catapilla]

Many Thanks for your points,
 
 Bob - I am not going to run the road train,
 (I was employed to drive it in the late 80s) although I guess it would raise some eyebrows on the salt especially full of NT Cattle!
 
 I am looking for the rules and classes and would appreciate any links that can get a newcomer on the right track to designing a Chasis/Machine.
 
 Dan - is Hot Rod that you have mentioned - hotrod.com?
 
 Much Appreciated for all advice.

[dwarner]

I was referring to Hot Rod magazine. I don't know if they post the current articles on line. You can purchase a 2005 Rules and Record book from the SCTA on their website: www.scta-bni.org.

[600Catapilla]

Many Thanks Dan
 
 I will see if I can source Hot Rod here in South Australia.

[ProDrivers]

"The balance between HP, weight distribution and aero balance is foremost in LSR."


With weight distribution being a key factor, you still need a starting point.

50% on the front and 50% on the back?

I find this very interesting as I use to drive sidedars and set the unit up myself. I know what the difference can be in moving the weight as little as 6 inches forward. The difference in toeing out the hack and putting a few degrees of angle out on the bike, so that when you get to road speed, the thing acually straightens out.

In other words, it is set up to run at highway speed, not town speed.

Do LSR cars need the same consideration. Not designed to run at 50 mph, they are designed to run at, in my situation, 200 mph?