underboosting

[Bobers9]

hi, i keep having this issue where im only making 3 pounds of boost off gate slowly rolling into it, it used to make the 10 psi gate pressure immediately on my 2 bar setup but on the the 3 bar i cant seem to figure out the issue,current three bar map tune.hptonly building 3 pounds.hplprior 2 bar functional tune.hpt . idk if im missing something in the tune. ive checked cold side for leaks, bov is functional, no pre turbo exhaust leaks, twin turbo setup and both wastegates arent opening pre maturely. any help is appreciated.

[5FDP]

I have questions.

What 3 BAR MAP sensor?

Why is stoich set to 13.00, are you actually running fuel that is suppose to run at 13.00? Because you don't fudge with that number if you are running regular pump gas, that will throw all your fueling off and likely a reason why your VE looks terrible.

Probably also a reason why your EQ ratio commanded is at 0.750, do you not understand how the table works? You need values greater than 1.00 to command richer than stoich but if your injector data is fucked up and you are commanding the wrong stoich ratio, that will be why your tune looks so goofy.

Speed density isn't set right either, the MAF dtc's need to be MIL on first error.

There is alot more that really weird in that tune, needs a lot of work.

[Bobers9]

3 bar sensor is efi source's ls1 style, ive reset the stoich back to 14.68, fixed the mil isue, and no i didnt quite understand the eq ratio commanded table. my injector data should be accurate, https://docs.google.com/spreadsheets...gid=1038321039 this is the google doc snake eater had provided for the 1500 multec 2's

[Alvin]

I would use a GM sensor. I have zero faith in these aftermarket map sensors. I've seen too many bad ones personally and as a shop I get emails from china all the time offering bulk discounts on stuff like that.

[SiriusC1024]

I've seen even the "good" aftermarket sensors from places like Jegs report wrong. I've also seen this lead to to incorrect cylinder airmass>incorrect (retarded) timing>incomplete burn fooling O2's into reading lean and adding fuel>fuel in oil>bearings destroyed. Use OE or OEM.