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Old 01-25-2006, 07:56 PM
  #17072  
Nick-C
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Join Date: Jul 2005
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Originally Posted by Smoking motor..
Note I respect your knowledge and your probably faster driver than me.
But please look at what I am saying.
Before I jump in and make myself look like an idiot I would like to say that I respect your obvious knowledge of automotive engineering. It takes a lot to grasp many of these concepts and you apprear to have your arms around them quite well.

My dad was an amazing engineer yet he couldn't understand why 12th scale cars looked the way they did. He like many others felt that full scale automobiles had the strongest design concepts and that 12th scale designers should pay more attention to them. The biggest thing my father and most engineers fail to understand is really the easiest of concepts. Call it what you will KISS or Ockam's Razor.

12th scale cars move at speeds of 30-45mph and weigh in around 1 3/4 pounds at maximum. Do the math, that's an F1 car per say that moves at 360-540mph yet only weighs 21 pounds. How on earth could you begin to compare the two?

Your example of tire density to create traction also seems a little skewed to me. What you are talking about is generating surface traction, full scale race cars using air pressure for tuning the same way we use foam density. They are not creating dampening at all, simply controlling the amount of physical traction to the surface.

The compression strength of our wheels seems to be quite high considering the load they endure and really should not be considered as part of the equation. The issue here is that if you take the load being applied to the tire and transfer that through your suspension system to the chassis flat materials will begin to flex. Think about how much force is being put on that chassis plate after the lever effect of the rear end. The only good way to overcome this flexing is to make the material thick enough or use material with higher torsional properties until this critical flex point has been overcome. If you allow this twisting you are just turning the whole car into a T-bar and allowing the chassis to provide spring effect totally unchecked and with no adjustability at all.

I have never liked the idea of a T-bar and have plenty of experience with them. You are relying on a hunk of fiberglass that flexes to remain consistent. Every time that fiberglass flexes it's properties will change and generate inconsistency. By using a T-bar you have created what I call a "minimum effect" to the car, no matter what you change there is no way to reduce the amount of tension side to side or front to back to a value less than what the T-bar is providing. The only real solution is to run an extremely soft T-bar and add springs to fine tune tension side to side along with the center shock. By moving to the link design you have no "minimum effect" in the car at all. The lack of a "minimum effect" allows you to maintain complete control over side to side and front to back tension with a much higher degree of consistency.

At any rate this is a great discussion with some interesting points being made.
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