Speaking of rain..

standing water or just wet surface?

i'm thinking temperature might play in here also.

Depends... Whole race under rain? highly unlikely... I've got "steamrollers" on my Audi, and there is not a lick of hydroplaning at high speed, even in a downpour. This is Lemons, not F1. Run what ya brung and drive the tires to the limit of the current environmental conditions. I optimize for dry, and take what comes - even with my "real" race car (relative to the rest of the pack, I'm actually faster in the wet than the dry)

For wet pavement you want the same kind of tire as dry pavement.  The tread compound has an effect on wet traction, but it is not related to treadwear.  In standing water you want a rounder longer contact patch.   That means a more narrow tire at a higher pressure.

You can buy a rain specific tire that has a tread shape to help water evacuation and a tread compound made for wet conditions.   If you want to minimize problems with hydroplaning you can run on the high side for pressure.  You will loose some grip on the wet pavement, but you will have a better chance of keeping the tires on the pavement in deep water.

Combine wet weather with cold (like CMP this weekend) and you run into additional problems.  Performance tires with sticky treads have a high glass transition temperature.   The tread compound will have low grip at low temperatures.  Sticky tires do relate strongly to tread life.  Higher treadwear tires tend to be optimized for all season performance and have better cold temp performance.

Today we were seriously considering caging the '96 Continental that I picked up for $500 on CL. Bad front right air strut, though, and it wouldn't be as fast as the Mark despite having the same motor (no time to gut/prep it). Plus, I wanted to make it my DD. Still, it would have more traction on a slick track, and heat, not to mention A WINDSHIELD.

All he needs is some dealer plates to DD it, right? Gotta be a dealer on some NorCal team that can loan him a set...

That's my old car (the Quattro Libre).  Now we're driving an unreliable rear wheel drive Italian sedan that lacks grip on DRY pavement (but I wouldn't trade her for anything else)!  Taylor B. got the deal of the century when we sold him the Libre.  Curses!

1/4 inch plywood and some zip ties will fix that....

Yeah, that's our old car now, too.  Taylor was too lazy to fix the tranny on the Libre, so we're bringing a (hopefully) reliable rear wheel drive Swedish sedan.  If we do get rain, I'll wish we had the Libre.  She needs a lot of love, but she'll totally be back this season.