Today Mark and I had prearranged to fly a new experiment 2 pilot jet. When we got in the jet mark dropped his joking attitude and became sedate. When we took off in the jet we instantly started gaining altitude we were moving very fast when BOOM the after burner exploded. We were over a remote area so we were less concerned were the jet was going to crash. As we jumped out of the jet it crashed into a ridged cliff. We instantly felt embarrassed for we had tried to go too fast too soon.