same could be said about guys at the track on the scales, if your on the scales at the track you are behind the 8 ball, we do just as Brian mentions, we have a favorite setup that we call the baseline, adjustments from that point are seat of the pants and laptime adjustments.I should know better (my time is too valuable for some debate)....BUT
How much does the psi change the profile? What brand of tire are we talking about?
When cutting a tire using a template, I see very little (ie .001" = one thousandths of an inch = way smaller than the width of a human hair) when adjusting air pressure by 2 psi. It isn't until you reach around 15 psi in a tire that you effectively change the profile (ie balloons out the center of the tire.) Recognizing that dirt racers will never see that high of PSI, why is it that you think that a real, although minute, profile change (if it is even measureable at all) would affect the handling? Furthermore, when running very low psi (ie 4-6 psi) in kart tires with the sidewalls pulled out as much as we do, and 350-400 pounds pushing them down onto scale pads changes the profile dramatically more - then consider how they deflect under loading on the track (ie acceleration, cornering, lateral g-forces, etc.) I think we would be really splitting hairs (literally) on a pound or two changing the profile being the reason that the kart handles differently.
No doubt that air pressure splits affect handling, but I feel that the tire profile (at the pressures that we race at) has very little to do with that change in handling.
I think of psi affecting the spring rate of the tire moreso than the contact patch. That IS something measurable.
Personally, I think too many racers race on scales -- Gone are the days of a guy being able to set up a kart by the seat of his pants. Instead we see guys plugging in "factory" set-ups and then wonder why they can't hit their behinds running up "norf" on our black dirt oval tracks and floppy sidewall tires.
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Really we are very seldom on the scales anymore, when we first started we spent hours just making
And Brian it may just be a 1 lb split, but if nothing else is change but just the split changed you can fell it by the seat of the pants.
We run no split, and have run negative split.
I say try both ways
I agree, same numbers with a 1 lb split versus n spilt, the kart will handle differently, a change that can be felt while on trackI'm not sure what your argument would be?
The original post was resetting to same scale number, would there be a handling change?
If a 1 psi change to the left side creates a negligible change to scale weights, then the lf and lr changes cancel each other, for the most part.
Contact patch, both statically, and dynamically, is what makes the handling difference.