Thread: WRF BATracer Wet Weather Guide

This is an enhanced version of the BATracer Wet Weather Guide by Tom Hartley

As BATracers we often face the uncertainties of changing weather. But how do we adapt our setups and tyres to these changes?

In BATracer, there are 12 different weather conditions, shown below, ranging from Bone Dry through Rain to Monsoon. Because there are 12 weather conditions in total, we can easily determine what is referred to as the 'Wet Factor' (or how wet the circuit is in numerical terms).

Bone Dry = 0% Wet Factor
Greasy = 9% Wet Factor
Moist= 18% Wet Factor
Drizzle = 27% Wet Factor
Light Rain = 36% Wet Factor
Rain = 45% Wet Factor
Wet and Slippery = 54% Wet Factor
Steady Rain = 63% Wet Factor
Heavy Rain = 72% Wet Factor
Treacherous Rain = 81% Wet Factor
Monsoon = 90% Wet Factor
Storm = 100% Wet Factor

To better understand the 'Wet Factor' and how we can use it to adapt our setups, we will assume that there is a practice session in Bone Dry conditions, but the weather for qualifying is forecast as Rain.

Adapting the Setup

As illustrated above, each weather changed is accompanied by a 9% change of the values recommended in the 'Engineers Advice' in the 'Setup' menu. A change through 9 weather stages is a 45% change.

Let's say that you would have to change your setup from bone dry to wet & slippery. Go check the Engineer's Advice for weather changes to setups...

Fully Wet:
Wings
Front +20
(If 20 is 100%, we need to find what percentage wet and slippery is, which in this case is 54%, so what is 54% of our value?)
So the sum is as follows
20 / 100 = 0.2 (that is 1%)
0.2 * 54 = 10.8 (this is 54% of 20, so we'll round to 11 so we have a whole number)

Apply same system to every setting parameter and voila, you got the setup changed. With Kool Tools this is obviously little faster...

Choosing the Right Tyre

If you are not sure what tyre to use in practice sessions if the weather is moist or such, go and check the timesheet to see what tyres your competitors have used there (not available in every carset). In time you will find out which tyres are suitable for current weather condition.

I have the exact Kool Tools wet/dry +/- conversions if anyone wants them. (ie dry to wet = +xx wet.)

You have the % change, I have the exact KT +/- values. For example Dry to Greasy is a 9% wet change. You can manually change all your numbers 9% based on the full wet blah blah blah, OR 9% wet = +4.5 in the KT menu. All you have to do is move the slider +4 or 5 wet and you're done. I have all the values in that form.

Originally Posted by EIR Loe.307

I have the exact Kool Tools wet/dry +/- conversions if anyone wants them. (ie dry to wet = +xx wet.)

I don't think that is necessarry since there is also another formula to count the weather changes...

Originally Posted by Harakimi

I don't think that is necessarry since there is also another formula to count the weather changes...

Is it as easy?

Originally Posted by EIR Loe.307

Is it as easy?

Not as easy but more exact.

I know you can take the full wet and multiply by blah blah and get each individual # that way. Pain in the arse!! +1 = 2% way easier. Got me pole in the Pescalero!! or was it the Renault???