Depends on the temperature. Put some white shoe polish on you sidewall by the arrow. Make a run to get some heat in the tires and see where you are in relation to the arrow.
My first autocross was in 90+ degree day and I was running about 27 lbs. Tires worked well. The following weekend we had a night autocross and it was 15 degrees cooler. Car felt like it was on ice as the night cooled down. Those in the "know" were adding a little air through the night. Next time I will know better too.
Hook up with a racer in the know who has experience with Toyos. A lot of the AZ PCA guys like the tire as it works well for autocross and track too.
Post your experiences. We can all work through these thing.