i just thought i would also add to this post, i also have a Lipp Boss series turbo, stage 5 57 trim, 550s,lex, safc,wideband, fpr, 255walbro. i also have a fully built 7M. I absolutly love the lipp boss turbo, it has SOOOO much more top end power than an upgraded CT turbo does, its absolutly amazing.
At 18psi i made 370hp on the dyno, but then found out my timing was at 0!! lol, so i got my timing back up to 11* and that really gave me the power i was missing. big difference. so im positive iam now over the 400hp mark at around 18psi. About a week ago i was out on the interstate driving and i had my boost turned up more, i was hitting around 27psi and my tires would break loose and spin going 95mph.. i really need to dyno agian now that i have some timing and other issues fixed, iam also able to run more boost now. I would say 500hp is deffinetly attainable, im pretty sure if i were to dyno at 27psi on 110 race gas i would be right around 500hp. My car also runs pretty rich, even at high boost its rich and i have a decent amount of fuel taken out with the safc.