Pretty sure it's 1/8 looking at some of the class payouts.
4.70 Guarantee Purse Entry-$150 First-$1500 Second-$500 Third-$100 Fourth-Free Entry
5.00 Payback 75% Entry-$100 5.70 Purse Based on 16 Car Count Entry-$100 First-$1500 Second-$400 Third-$100 Fourth-Free Entry
6.00 Purse Based on 32 Car Count - Winner $2000 Entry-$50 Purse Based on 24 Car Count First-$1000 Second-$300 Third-$100 Fourth-Free Entry
7.00 Purse Based on 32 Car Count - Winner $2000 Entry-$50 Purse Based on 24 Car Count First-$1000 Second-$300 Third-$100 Fourth-Free Entry