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driver comparisons vs tire pressure

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I had an opportunity this weekend to run tires for several drivers, not getting into who, what and when, and if you know, please don't post them, ( thanks ahead of time) but it was pretty interesting to see the results of their driving styles. Generally, the higher the tire pressures, the harder the car is being driven, but only to a point. Somewhere out there it goes in the other direction, the "straighter", or smoother you drive the car, the less the psi will build.
As an example, driver A on a 28/29 split was From right front clockwise..28, .. 29.5,...30.1,... 28.2.
so I pulled .5 out of the RR and 1.1 out of the LR.
Insert new driver (B) and sent him out
Driver B 28.2,... 28.7,... 28.7,... 28.1

So driver C goes out in another car on a 29/30 split and runs a 27.3,.. 28,... 28.2,... 27.1..
but look what happens when we put driver B in the second car with the same pressures
Driver B 29.2,... 30.2,.. 30,... 29.3

So we see both examples here, in the top post (Call it car #1) we see a driver who might be overdriving the car a bit, most likely spinning the tires coming off the corner, building up extra pressure in the rears, after correcting for the pressure increase, driver B takes the car out and drives it "straighter" coming off the corners, so the rears never quite hit our hot marks.
In the second example, driver C takes the car out never really gets up to pressure, because he's not driving the car hard enough, but this time, the tire guy has learned his lesson and leaves the tire pressures alone. The tire pressures come up and come pretty close to where we need to be.
So to further confuse this, keep in mind we have to change drivers in mid race, and of course the ambient and track temps change as well. This is part of my challenge and why I'm so attentive to the small items in tire prep.
So we kind of see 3 types of driving styles here, driver A where the driver may push too hard (slower lap times). Driver B who runs the car straight, and has great lap times, and driver C who probably is under driving the car a bit. Driver B has the best, most consistent lap times, and the most consistent tire pressures.
There is a third challenge as well, let's say that the tire responds best at 30psi, BUT.. and this is a very big BUT , I cannot have the rear tires below 17.5 psi on the starting grid, so the guy spinning the rear tires, artificially building pressure, will run out of tire way before the end of the race, because the tire can gain as much as 15 psi in that example, it will also be operating outside of it's optimum pressure range. The guy that drives the car straight will not build the pressure as much, preserve the tire and keep it in it's optimum operating range.
 
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sfo
I wonder at what point you overdrive in an attempt to lower laptime? Is there are rule of thumb for say driver #2 being smooth and fast grows tires 10psi. Underdriving grows 8psi while overdriving grows 15psi?
 
3,611
3,436
I wonder at what point you overdrive in an attempt to lower laptime? Is there are rule of thumb for say driver #2 being smooth and fast grows tires 10psi. Underdriving grows 8psi while overdriving grows 15psi?
I'm sure it could be graphed and would show exactly what you said. remember over driving will slow the lap time and take the tire out of it's operating range. Similar to boosting qualifying pressures, you get 3 laps, make the best of it.
 

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