Tuner Studio MAP gauge don't match test gauge

[oldskool]

Hi, I assembled MS3 from DIYautotune, tested with JimStim 1.5. All tested good except boost/PSI gauge, with Mityvac pump reading 15" vacuum, Tuner Studio gauge shows 7.8" vacuum. I since installed in car, started 2nd try with surging idle. Adjusted IAC settings, some idle improvement. MS3's MPX4250 MAP settings are 10 at 0v, 260 at 5v. Changed 260 to 350, car idles good. Base MAP/engine off reading with MPX4250 settings 84.3 kpa(with 350 at 5v, kpa goes up to 113 with engine off), 84.3 kpa accurate for 5,000' elevation = 12.23 psi. Able to drive car, used TS VE Live's Autotune, was correcting cels till 30% throttl, starts missing. Any ideas to correct Tuner Studios MAP gauge? I've used 3 different vacuum gauge to compare to TS gauge. I don't think it 'd be wise to continue Autotune with incorrect MAP info. Thank You.
David

77 Pontiac 400 stock 190HP test engine,
HEI7 controlled w/MS3X,
bank 2 bank port w/38's,
LS1 75mm TB,
GM 4 wire stepper IAC,
5,000 Altitude,
91 octane

[LT401Vette]

Yes it is a good idea to make sure all sensor readings are right before using VE Analyze.

What is you elevation actual elevation?

It is easier if we talk in absolute pressure as vacuum is going to be calculated from that with barometric pressure factored in.
What is the MAP reading when your Mityvac is reading 15" vacuum?

[oldskool]

Phil, after what you explained about kPa being accurate especially at high elevation, I'm at 5,000 above sea level, I tried what you said. I changed MAP in Tuner Studio back to MXP4250(default settings) that came with MS3. It wouldn't idle till I enriched some idle settings, VE Analyze Live started correcting idle. 1st log today in town driving, 2nd log headed for highway, then on Interstate. Still need more driving. On Interstate I gave it 75% throttle, didn't miss or bog! I have twin T04E's on car just spinning, I'll do more Autotune getting AFR's close before I hook TB to turbos. Any recommendations when I attach turbo charge pipe? Tuner Studio & support is AWESOME! Thanks Phil.

[LT401Vette]

The VE Table doesn't look like it has changed from the default much. Is VE Analyze changing it at all?
Watch the VE Analyze Stats and see if there is an active filter that is preventing it from making change.

You might as well set up you Y Axis for the boost. If you upgrade to the TunerStudio beta, it has a VE table generator in it that will generate new Y Axis's for you based on your input.