Equation for PSI value in ADX

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Equation for PSI value in ADX

Postby 0081(2) » Mon Apr 28, 2014 8:37 pm

I would like to add a PSI value into into my ADX, it currently has the number displaying in KPA but i would like to be able to see it as a PSI reading also.

I just dont know what the equation would need to be
the one for KPA is (X * 0.781) + 8

What would i need to have here for the PSI value ?

Peter

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Re: Equation for PSI value in ADX

Postby Jayme » Mon Apr 28, 2014 9:00 pm

enclose the whole lot in brackets and multiply by the conversion factor from kpa to psi, which is 0.1450

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Re: Equation for PSI value in ADX

Postby 0081(2) » Mon Apr 28, 2014 9:17 pm

so your saying it should read

((X * 0.781) + 8) * 0.1450

Because it doesn't appear to be right when i play the log back

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Re: Equation for PSI value in ADX

Postby Jayme » Mon Apr 28, 2014 9:49 pm

well if you want boost psi you will have to minus the atmospheric pressure off of it. so more like (((X * 0.781) + 8) * 0.1450) - 14.50

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Re: Equation for PSI value in ADX

Postby Holden202T » Mon Apr 28, 2014 10:07 pm

this is what I use for a 3 bar map sensor to get boost PSI

X * 0.177 - 14.185

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Re: Equation for PSI value in ADX

Postby 0081(2) » Mon Apr 28, 2014 10:35 pm

Thats a bit more simple what would you use for a 2bar

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Re: Equation for PSI value in ADX

Postby VL400 » Tue Apr 29, 2014 7:29 pm

The easiest option (and the best for the least rounding error) is what Jayme suggested. If you want to simplify it the calc is...
2 Bar = (X * 0.113)-13.54
3 Bar = (X * 0.177)-14.381

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Re: Equation for PSI value in ADX

Postby Holden202T » Tue Apr 29, 2014 11:22 pm

yeah I only use it with zero decimal place, I don't really care exactly what it is, just want to get an idea of what PSI its running when I change wastegate springs and the like.

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Re: Equation for PSI value in ADX

Postby 0081(2) » Wed Apr 30, 2014 11:25 am

Thanks for that info, I guess I could have worked it out but was a bit unsure what most of the values where for.

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Re: Equation for PSI value in ADX

Postby VL400 » Wed Apr 30, 2014 6:34 pm

Will certainly be accurate to 1 decimal place :thumbup:

You could also change the calc to reference baro, so you see the true boost pressure.

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