So I've been around HP Tuners with GM stuff for 15 years, but I've never actually done anything with anything GEN IV, only GEN III and GEN V. I've also never really done much with forced induction until now and I am finding out some limitations and things I screwed up and trying to read through all kinds of old threads and try to re-remember the stuff I used to know.
I've got a 2011 Sierra Denali I am putting a turbo on, and I got a 3-bar MAP (12592525), but I guess there is a 2.5 bar limit on custom OS's on E38s so I guess I can't go that route. That is ok since I can use VVE (I think?) and just scale the VVE editor to whatever limits I want and re-calc coefficients. The other thing is I can't find a custom 2/3 bar OS to use after searching everywhere on the forums. The only ones I found were for Camaros and other cars and not for trucks. I know we are not supposed to be full flashing OS's unless its something similar. I know with GEN III stuff I used to flash all kinds of different random OS's to see what would happen and hoping they may have "enhanced" functionality.
With that said I would love to go MAF, but it seems like MAF is the enemy of people especially with turbos, and they have to kill it at all costs. I feel like MAF is good and will help me report accurate airmass/flow for torque based dependent operations like transmission and traction control. My problem is I can't find the proper hoses and tubes to fit my MAF, even though I could go to one of those aftermarket ones, but that's a different story.
So I am assuming HPT has changed something with their custom OS's because this "Speed Density Air Mode Patch" isn't in the documentation, and all the relevant HPT Forums posts that have the relevant info I need on all these questions have been deleted for whatever reason, but they still come up in search engines.
Also if the documentation said only up to 2.5 bar MAPs are supported, I guess I can't use this supposed 3 bar MAP at all? I was thinking all the MAPs they make were calibrated to max out at their pressure limit at the same voltage, so why does the electronics/software care?
Also my current stock truck OS is 12639835. Thanks for the help.