I am going to ramble and run amock here - it is sort of the way my head works... consider this a white boarding session of sorts...
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I built out a Boss 429 using the Tonka Toy last night. I had the handling set to 6.13 in order to generate an ARB setting as close to 27 (27.01) as I could get. The Total rebound came out to 14.8, and with a Race level WR weight of 2602, the Total Spring came out to 734.4. I set my car up with the results of applying a 53% Wb.
The car was a bit quick to turn in and a tad oversteerish - setting the Castor to 5.1 to slow steering response and eventually changing the Wb to 54% helped some. But the car was still a bit dicey to drive. The best way I can describe it is that it felt light. It sort of floated around on the road. My thoughts when problems arose is that the car needed weight.
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We have had some discussion on what to consider - what to call - the results of dividing the Total Spring rate (either for half or the whole car) by the curb weight. I think the number has more of an "automotive" flavor if spring rate of the whole car is used. Then someone can say something like... "My springs are set to 74% of my cars weight." Or if you insist, he could say, "My springs are set to 37% of my cars weight." but somehow that doesn't relate to me as well as the other.
This is not
Sprung Weight nor is the result of subtracting this value from 1 the percentage of
Unsprung Weight. We've had this discussion. The super cars muck that thought all up. And, the idea that an R4 car would have a 40% unsprung weight seems ludicrous as well.
Whatever we call it, the sentence makes sense. My spring rate is <this> percent of my car's curb weight. This can be calculated quite easily - just multiply the curb weight by the spring rate percent (ratio?)
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The Spring Weight Ratio that the calculator was producing was 55.78%. In order for me to get a set of spring values that approximated the values that the car had, I had to set the handling variable to 8.0 - this also netted me a Total ARB of 35.52, and a Total Rebound of 16.9. I was a bit uncomfortable with the ARB value, in the interest of science however, I
will try it today.
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Back to my floating assed Boss - I calculated a set of springs using a Spring Weight Ratio of 72.8% which gave me spring rates just a tad stiffer than what I'd had. This got rid of the floats! I ended up setting my best time on Laguna Seca to date with a MInc B car, an improvement of .6xx seconds over the previous time, in just a few laps. My current goal for this track and a Muscle car is to beat 93.5 seconds, and that seems within reach right now.
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So, in my mind, something is not right about the way the Tonka Toy calculates the spring rate. I'm not saying, "Error" or "Bug" - just that the value is not turning out as is required by the cars in question.
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Another life ago when I was a young man in Colorado, I had a logging and firewood business. I sold my firewood by the cord, a unit of measure that equates to 128 cubic feet - commonly described as a stack of wood 4' x 8' x 4'. There is another unit of measure used for firewood - a rick (ric, rik
). This is a stack of firewood 4' x 8'. It is missing a dimension. The volume of the rick ends up being a factor of length the chunks of wood are cut to. If the sticks are 2' long, you have half a cord. If they are 16", you have a third of a cord. In order to get an accurate number about the acutal volume of a rick, you would have to measure the length of each stick. If one were to then try to plot the volume of a rick of wood, he would have to use a scatter graph because the values would be all over the place.
Or consider...
"Bring me a 2 x 10 for a floor joist."
"How long do you want it?"
"Damn, do I have to tell you everything?"
Trying to build something without all the dimensions is rough business at best.
Now before you go to hollerin' "Blooze, have you lost your ever lovin' mind?", go and sort Tonka's data by the last column - the Spring % Weight field. Then look at the Class, PI, and Handling fields when sorted in this order. If a stiffer spring rate is an indicator of better performance, then the R4 cars are among the worst cars in the game. And the Super Cars are much better than the R1 cars.
We are missing a dimension. And a scatter graph would be required to plot the data.
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So what is the missing dimension?
Well first, a couple points
- I think relating the ARBs and the Weight as they are related in the spring calculation is an incorrect supposition. If for no other reason, notice that in the game, the ARB values do not change no matter what you do to the weight. And secondly, the results do not work.
- Aerodynamic settings were not included, nor should they be. For my part, I understand very little about how they are applied and what the values supplied mean in the forms of units of gravity. Then consider that the gravity affect is variable by speed... But, this doesn't mean that the Aerodyamics should not be considered. In short, the reason the R1 cars get away with the suspension settings they have is due to the fact that they have 766 units of downforce being applied to them as well.
I think the missing dimension is the Spring Weight Ratio (SWR). I will stipulate:
SWR = ((FSR + RSR) * 2) / CW
where:
- FSR = Front Spring Rate
- RSR = Rear Spring Rate
- CW = Curb Weight
Consider that the SWR is available to us as soon as we purchase the Race level Springs. It can be calculated from default values. It will change as the CW changes when weight affecting parts are purchased. Consider also that this value can be stipulated, much the way we can stipulate the Wb, and now the Handling Stat. If the stock SWR is 72%, I can stiffen this by saying I want it to be 74%.
Then in the calculator, the Total Spring calculation would then become simply...
Total Spring = CW * SWR * .5
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Okay, I am going to put the caps back on all the little markers and yield the floor.
Your turn...
$
