Hey Steve, I performed a similar experiment a couple of weeks ago. I started with 6.5 gallons of 64 degree water and achieved a boil in 1 hr 40min. My stove is equipped with a 12,500 btu "Power Burner". From what have read the norm for burner is 9,500 to 10,000 btu's.
One suggestion that I have not tried yet is wrapping the bottom of the pot with 6-8 layers of aluminum foil. It's applied it in such a way that it went down past the bottom of the pot but allowed enough of a gap between the pot and the stove top to allow air to get in and keep from starving the flame. Someone else posted that this decreased their time to achieve a full boil. I'm not sure how this would work on an electric range but it may be worth a shot. Good luck hope it works out for you.