It's at the Valero station on the corner of Ford and Haggerty in Canton, MI. I just looked up Turbo Blue and it looks like the "Turbo Blue Unleaded" which was on the pump sticker, is 100 octane.
I don't expect to make any more power because I'm tuned for 93, but I thought a few gallons might give me a bit of added protection in case I do anything retarded like slam the rev limiter accidentally or have a methanol system failure during the race.
I don't think I trust the bottled octane boosters at the parts store.