Unless we are all using the same measuring tools under the same conditions, can we really compare boost levels with any accuracy?
A poster on another forum, who often takes his SHO to LMS and has a relationship with Dan Millen, told me that his custom dyno tune only produced boost in the 13 PSI range. The key, according to him, is the amount of sustained boost (along with appropriate timing and A/F ratio) and NOT maximum boost spikes. Supposedly, the 4X is a more streetable version of his dyno tune. Again, I do not know the conditions or what he uses to measure boost. I know he has a low 12 second SHO, though, without using meth.