I have been toying around with a recipe that will end up with around 80 IBU's, but only about 20 in the 60 minute boil and then Super back loaded for more Hop flavoring. I was planing on a Citra/Amarillo combo or maybe something with Simcoe. My question is will this have any effects that I am not thinking about in my recipe?
There's a recipe for an IIPA on the "Can You Brew It" podcasts called "The Dankness". It calculates at less than 55 IBUs, but the actual IBUs are probably much higher due to the heavy, and I mean, HEAVY, late additions and whirlpool additions. I think their bittering addition is only 15-25 IBUs.
I think Heady Topper also skips the traditional bittering addition and focuses entirely on 15-10-5-0-DH. That's speculation though.