Thread: gmn 3bar setting in in adc

What do you guys for setting the min and max value to correspond to gauge value.

I tried -12.9 for min and 29.0 for max. I correspond for boost value in psi. However it doesn't correspond to vacuum. For example. gauge value of 15 in/hg report as -6.


Is it possible to correspond between gauge and gm 3 bar value in the vacuum range.?


I still have knock retard whenever I am boost even at 1psi even with new turbo.
This billet compressor is amazing. As soon as you floor the pedal you are in boost.


As soon it reach 1psi. boom 5 degree retard. So I reduced that area with 5 degree. It still give me knock retard.. Is knock really happen
at 1psi with 17degreee timing 11.5 afr.

Thanks

Vacuum does not translate to psi and is registered in mmHG. Do the calculation and check back.

Yes, it is kind of hard. 3bar sensor is 0 to 44psi absolute pressure. psi to in/hg is different scale. Why would they put 2 different scale in 1 gauge?

When I put -12.9 to 29 is kind of right for me since boost since is almost right , that's what I really interested in. This is going to be a bitch to tune in Map.

I really want to use map system since I pop hose on hwy several times .

Dude, you are way overthinking this one. It won't be hard to tune.

If you have a GM 3bar MAP sensor, use the default values for a GM.

I'm also assuming you have an analogue pod gauge, which you are trying to match the digital readout from the GM sensor? The +- accuracy of these two are never going to match up perfectly on both ends of the scale, so don't even bother.

I personally use the 'mbar' scale, and I find it the simplest thing ever to tune on turbo+MAP. Having multiple units in a load scale is just silly.

If anyone wants to try this scale, here are the basics. (3bar GM)
1bar = 1000mbar = atmospheric pressure. This is WOT on a NA car
<1000mbar, is vacuum. That means partial throttle and idle, that produces the lowest readings.
>1000mbar is boost. You can run 2 bars of boost (3bar absolute) with the GM sensor.

I would dare to say anyone who tries this will never go back to psi

Errrr, last I checked, about 90% of boost gauges have both units on the same gauge............why would this be any different

A 3 bar map sensor also registers vacuum.

As stated above, way overthinking this. I urge you to do the calculation I mentioned above and report back. You just spent days harping over this when you could have had this all figured out in a matter of minutes

P.S I had the same thought process as yourself and tried tirelessly to match up what the NEMU/GM 3 bar was registering and what my boost gauge was displaying until I realized the units were the culprit. At that point is when I realized the base settings John has set in the NEMU for the GM 3 bar is about 95-98% of the way there and only required me to adjust the scale by a few points.

Goodluck!