So I know that it’ll depend on the brand of tires, but does anyone have any general guidelines of what PSI to set rain tires at?
On Bridgestones and MGs, 20psi is our general mid-range pressure. Lower for a drying track, higher for a wet track.
You can tweak pressure based on how wet the surface is, and/or average speed of the track.
Higher pressure with wets usually has a double effect, smaller contact patch (more pressure on surface to cut through the water) and it opens up the pores in the tread to displace more water.
One of those experience things.
My experience is lower pressures then TJ prescribes. It would have to be torrential for me to go above 20 and then probably only with mojos.
A few weekends ago with qualifying in the wet on Mojos we ran 16psi. Track didn’t have much standing water but it was definitely wet.