Ok i put a wideband on my car earlier today and got some pretty good results with the mbc. set at 17 psi here is what happened average of three runs. during boost buildup say around 10-12 psi at around 3000 rpms the afrs averaged around 12.0-12.1 but by by the time full boost at 3800 rpms it would drop to 10.8-11.1 then it would contiue to get richer hiting around 10.3-10.5 by redline while hold full boost 17-18psi max! The car ran extremley well even in the texas heat. And check this out at one time i had the boost turned up allittle to much to where it would hit 20psi at redline and the AFR's stayed at 10.8 , but im not trying to go that high because the car wasnt specifically tuned for it, so i tunred it down a notch. im very happy with the very consistant 17 psi in every gear, and my egt's didnt seem to get any hotter as the rpms rose so im going to keep the mbc now with allittle peace of mind.