SRT-4 Kills Vortech Supercharged GT

[oleblue]

One of my friends just got a Vortech supercharger put on his 2001 Mustang GT and had it dyno tuned at Modular Power House on 10psi with the SCT. He put down 400whp and 405wtq before the supercharger belt broke and had to have it towed home. He said the tuner said that they might could have got alittle more power out of it but it had a good tune on it and they were good to go when they get another belt. Anyways long story short we did about 6 different runs from a 40 roll. The first run I pulled a car through 2nd then missed 3nd and he came up to my passenger door by the time I got it in gear then I pulled about 3 or more cars on him through 3rd then let out. The second run we take off and he misses 3rd, and then again on the 3rd run, and on the 4th and 5th runs also he must be trying really hard or something. Well the 6th run he finally hit all gears right and I pulled on him pretty easy. He says he is going to up the boost and get retuned and put it on me the next time. Anyway I had a ball running him and thought I would share it with you guys. He claims he is going to up it from 10psi to about 15/16psi. I dont know much about those superchargers but what kind of a power gain should he get by upping the boost that much?