FWD vs RWD: Adders, Subtractors, and Weight, Oh my...!

[Knestis]

Exactly. A 200 HP ITS car needs a different amount of weight subtracted than a 200 HP ITR car because the wheel widths are different. If we used a single formula for all classes it would need a factor for the wheel width. Whether the single formula is feasible or desirable is another matter.

That's not actually what I meant but on further consideration, ultimately, we don't really need to CARE about comparisons between classes, do we? All that matters is that the factors applied within each class shake out to make for a reasonably equitable situation. A single FWD factor formula might have different effects on different classes but does it matter?

K

[ekim952522000]

That's not actually what I meant but on further consideration, ultimately, we don't really need to CARE about comparisons between classes, do we? All that matters is that the factors applied within each class shake out to make for a reasonably equitable situation. A single FWD factor formula might have different effects on different classes but does it matter?

K

I think in order to get it right we are going to have to use a different number within one formula for each class the same way you guys use 12.9 for ITS and 11.25 for ITR.

[Knestis]

I think in order to get it right we are going to have to use a different number within one formula for each class the same way you guys use 12.9 for ITS and 11.25 for ITR.

Help me understand what you mean by "right...?" The different class multiplier just accommodates the fact that all cars, regardless of power, tend to be about the same size "box," so weigh similar amounts. Are you just talking about making the adjustment amounts commensurate with that reality (e.g., preventing the adjustments from making too big an impact)...?

K

[ekim952522000]

Help me understand what you mean by "right...?" The different class multiplier just accommodates the fact that all cars, regardless of power, tend to be about the same size "box," so weigh similar amounts. Are you just talking about making the adjustment amounts commensurate with that reality (e.g., preventing the adjustments from making too big an impact)...?

K

What I was trying to say was I think using a single formula for all classes would most likely end up too much weight coming off of A cars and not enough coming off of R cars. (rereading what I wrote can see how it did not make much sense)

[Knestis]

What I was trying to say was I think using a single formula for all classes would most likely end up too much weight coming off of A cars and not enough coming off of R cars. (rereading what I wrote can see how it did not make much sense)

Okay - thanks. That's making sense for me now. I retract my earlier queston.

K

[lateapex911]

Yea, if we were to go with a single "all knowing" formula, it needs to be rather non linear for the reasons Mike points out. Complicating that is the non linear wheel width allowances. (Same for a couple classes, different for a few).

That's why I see the exercise as wiser to do class by class. Choose a mid point, then do the math with percentages.

I think my ITR numbers made sense, but I don't have the data I need to do ITS.

I'd REALLY like to figure out how to get LapSim to have a representative factor of our different wheel/tire widths injected to get a handle on the class to class interactions. While Kirk makes a good point that class to class isn't as important as we might at first assume, we need to remember that the classes are set up relative to each other.

If we can get lapSim to output reasonable numbers that help show the effects of increased traction available in the higher classes, we'd be further along in the setting of reasonable "bogeys"

Keep in mind that so far while it has been generating variables for differences in power, it has assumed grip to be the same, and it isn't in reality.

[Knestis]

Not.

K

[Andy Bettencourt]

I think in order to get it right we are going to have to use a different number within one formula for each class the same way you guys use 12.9 for ITS and 11.25 for ITR.

I agree. That is why I am still in line with the 5%, 2%, 5.2% etc that I came up with earlier.

[ekim952522000]

I agree. That is why I am still in line with the 5%, 2%, 5.2% etc that I came up with earlier.

I am also in agreement with those numbers Andy but feel like the adjusted pw/wt ratios are a slightly cleaner way to apply those percents. But is does not really matter you end up with the same numbers either way.