I understand tire pressures are a secret sauce kind of deal (I drove a car with someone and we liked noticeably different pressures on same tires and setup and were within 1% on laptimes) and understand if I get somewhat vague feedback but here it goes.
I've been running OEM wheels (17x7) with Dunlop Direzza ZII Star Specs, 215/45/17 (OEM size) and I don't think I've ever gotten them truly hooked up. At first I was keeping them in the 35-40 range any time I checked (cold and hot, I think I was around 38 hot usually after 20 minute HPDE session @ Laguna Seca in January) based on past suggestions for standard road tires for newbies they didn't want debeading on track and the tires felt peaky to me, like a little after the first lap they'd start to grip then around lap 3-4 they'd fall off a cliff and I'd be sliding around the rest of the 5-10 minutes in the session. They were certainly a great improvement over the Primacy HP's that made me glad I bought them but I was never blown away by the grip. After doing some research I now believe I had them overinflated as some people are shooting for 32 hot with these tires.
Current car setup: OEM unless otherwise noted, crash bolts put me at -1.1 degrees camber up front, ~-2/-1.7 degrees camber rear, zero toe front, 1/16th toe in rear, Carbotech XP10 pads front and rear. (The pads are overkill for my driving right now, oodles of life left and they work great and should last me quite a bit as I step up my skills, thanks CSG! Well worth the $$$ as the stockers will get 40k miles out of them.)
So at the last AutoX I tried going out at 29 psi cold, came back at 33-34 hot and dropped a psi or two until it was consistent at 32 for the final few runs (6 total), but the tires still felt like they weren't biting. Now the conditions were very chilly, mid 60's at best, overcast, strong stiff ocean wind. My current thought is that I had two things going on:
1. It was just too damn cold, tires never got heat in them, I never observed them to be hot, only warm to the touch, sometimes very warm but never uncomfortable or overly tacky to rest your hand on them once back in the staging area, they never tacked up like they did during HPDE.
2. I am still high on my tire pressures, given how cold it was with the wind and surface leaching heat out as I leisurely roll back to the grid over a few minutes I'm skewing my tire temps and I'm actually much higher 'hot' than I think. I didn't feel like the tires were sloppy with too much sidewall flex, next time I'll chalk the wear bars.
My current plan (AutoX in 3 weeks) is to repeat going out on 29 psi cold (ambient, no sun) and drop pressures after each session to see if I hit a sweet spot or when I make it to the bottom limit of what's good and start making it worse. I'm expecting 34-35 psi hot after the first run based on the last day and expected warmer weather and I'll keep the tires chalked. Since I'm not competing for points or anything, every session is a test & tune. Unless I learn something radical I'll be trying the same at my next HPDE.
The tires currently have 8k miles, 3x AutoX, 2x Track days (100 minutes each) and they are my daily drivers. They look pretty good and I'll be keeping them through the year no doubt, at least 1x more track day and probably 4x AutoX, based on how they're holding up they may last me into next year, we'll see how much tread is left come September to handle the wet season (lol 'season' in CA is a joke, I really mean puddles). I expect they'll have 10k miles, 3x track days (300 mins total), and about 50 AutoX runs total by the end of the year. They (Z2 SS) seem to have a strong following and solid AutoX results, I'd like to at least understand them before I use them up, I'd like to try something different but that's a ways off and these may survive well into next year the way they look today at about 50% of what
I expected their life to be. There are certainly counts of them being tolerable at ~200 runs but definitely not as quick, maybe they'll last me 1.5-2 years.
I'm really just looking to see if there's an idea or concept that will quicken the learning curve on these tires or a smack upside the head if I'm headed in the wrong direction.
Sidebar: When a course is biased to left/right handers and you end up with one side (left/right tires) taking more heat than the other, should you try to adjust it or leave the bias (say +1 psi on the right side) and adjust all four (or two, front or back to balance) equally? I'm still learning the ropes of road courses, in circle track racing every tire was treated differently and adjusting each tire had it's own effects within the car's current setup. While it's true with road courses as well setting all four tires differently to max out the important corners while compromising the less important corners is something even the pros struggle to do confidently and consistently.
Thanks for reading.
Aaand the thought just occurred to me to post this in a tire thread for cross reference...
Edit: For whatever reason I thought that this was the "Ask CSG Track/AutoX questions" not the suspension, oh well, tires are springs and people read this too
Maybe I'll cross post tomorrow if I don't get a response.