Bread-Bakers v102.n060.4

I was given a hearth kit for Christmas having until now have used quarry 
tile in my over.  My question is this.  I want to make popovers and they 
are to be started in a cold oven.  Now, since from what I've read, the 
hearth oven increases the pre-heat time in the over, how should I adjust my 
cooking time for the popovers?