ZDan

Has anyone found significant *lap time* benefit to running less than 30psi hot? Seems awfully low for a DOT radial...

From Hankook http://www.hankookracetire.com/wp-co...nd-Catalog.pdf
An approximate hot pressure target for DOT approved R-compound road racing tires is 40 psi. It could be a few pounds less for lighter cars, and a few pounds more for heavier cars. FWD cars may require higher inflation pressure in the front tires. Slicks for formula cars and sports racers should initially target for 22 psi hot. Changing hot inflation pressures to alter the handling characteristics of the car is a fine tuning adjustment. Improving the overall grip should be done with spring rates, dampers, sway bars, ride heights, alignment settings, etc.

Kenny_Stang

Interesting feedback, I will try a few sessions at higher pressures and see if they perform better. Will post back my results.

thomsbrain

Good point, I was front camber limited at -2.6 front, -2.8 rear. I was wearing a little past the arrows. But if you had over 3 degrees, maybe you could back off the pressure a little.

ZDan

Those arrows are not for setting pressures, they have nothing to do with setup at all. They point to the treadwear indicators in the tread grooves, and that is *all* they are for!

usafstud

I just called the vendor and their stock on these tires are 5+ years old. Is it a smart idea to use such old tires (unused) for track days? Do you use out on # of heat cycles it can handle with order tires or what?

Chibo

This is the first time I've heard anyone say do not use them as a reference in any way. I've generally used them to see if I am in the ballpark, not as an absolute, though it does make sense that it will vary based on camber.
Temperatures at the events around here start in the 40's during the first session and can end up in the 90's by lunch, it's difficult.

Again, I was hearing run lower pressures from people at the event, and now I hear run higher. I ran quicker times on less pressure, but there are a lot of variables in play. Just not a lot of concrete data floating around compared to something like a RE71R, NT01, RC1, etc.
I am willing to try them at 38psi hot next weekend.

At this point, these are for people looking for cheap tires to kill and play with. They are fine to track on.

usafstud

Chibo

I ran them today, and I will be running them again tomorrow. Was in the 40psi area hot and they acted like I had expected them to act. With that said, they were very consistent for the first three 20 minute sessions, though they did feel like they got overheated late into the last session of the day but that might have been a mental fatigue thing. I ended up going up a notch stiffer on my rear swaybar for today.

Depending on how long the grip lasts I might order another set.

Chibo

Very happy with how they worked, and they are not wearing visibly very quickly.
Again, laps only got quicker deeper in the sessions. I think this marks the end of my first track season with my S2000 as we are approaching summer in Arizona, and I am headed to Japan for April so no events then.

I guess there are two downsides to this tire if you occasionally track and do street drive your car somewhat frequently
1. They are loud as shit on the drive to / from the track
2. They do not like to be cold at all, they will spin on a mild 1-2 shift on the street in sub-70* weather

If you track frequently they have one downside:
They are marked 80 treadwear, so you cannot run them in a lot of grassroots level time attack / time trial groups, unless you're willing to take the non-points class or are willing to move up to a class that allows them. Locally, I am relegated to TA-R below 100TW in NASA and have to take an extra 2 points over RC1/RA1/R888/etc in S2K challenge.

I think the last part kills me because I'd really like to run the local NASA time attack series next year, so I will probably go RC1. Otherwise, I'd definitely buy another set of these given the really good cost/event ratio they seem to have. Almost HALF the price of the aforementioned tires.

Kenny_Stang

Thanks for the update Chibo, so did you feel that the tires performed better with higher tire pressures? What pressure were you starting out cold? I will be doing a two day NASA event this upcoming weekend, hoping to have great weather for a change.