I only have a 9 inch springform, how do you think this will change the time?

The recipe that I use for this cake uses slightly more batter in a 10" springform, but the baking method is different, and I have gone into it in the comments on the recipe. If you want to use Mr. Sax's method, I would drop the temperature 25 degrees and keep the time; this is basically a soufflé and can't be rushed, It should rise about 3/4" above the rim of the pan, then collapse, and should have formed a noticeable crust.