06 silverado turbo tuning

Hello everyone, Im new to the forum and im trying to get info on tuning my custom built turbo, a friend owns the efi live, but was having issues getting the cos to load, unfortunately I just read that there is no cos for the 2006+. So here is what im running mabe someone can help, Its a 2006 silverado 4.8l, 5 speed, custom built forward mount turbo, gm4 turbo, intercooled, spec stage 3 clutch, dura grip posi. Im getting 2.5 psi up to 3000 rpm, and 5-6 psi over that on stock tune, afr is reading pretty good, however my 1/4 mile times havent increased. Can i tune in a 2 bar maf without the cos? where else should we start? or should I rip this all out and go all motor? Thanks for your help.

Here is what i did for a customers 06 i did a front mount turbo on. Like you said there is not COS for and 06. I took an 04 TAC module and Throttle pedal and swapped it into the 06 then took an 04 OS and flashed it into the 06 PCM. Works great, no issues. I now can use COS with my 3 bar map. I got lucky and picked up the TAC module and Throttle pedal from a local junk yard for $150