MAP bar to PSI?

[gdrider77]

So trying to determine a few things on my car, most notably my actuator spring pressure and my boost gauge accuracy. I just put a new actuator on, that is suppose to be 8psi.

I uploaded a log with this post...

At max looks like my map reading is 1.25bar.

How does this translate to psi?

Converting this gives me 18.13psi, which i know is not correct. Using the info from this site....boostsource and this formula...

Absolute Pressure (psia) = Gauge Pressure (psig) + Ambient Pressure (psia)

That would then mean.... 18.13 - 14.7 = 3.43psi?

Thing is my gauge is reading around 8-8.5psi under full boost/WOT....AEM failsafe...
My old actuator at WOT full boost would read about 6psi.....
This new one is reading at 8-8.5 or so at WOT

So now really confused. Is it possible i setup the preload on the actuator arm wrong? Maybe thats causing the 8.5psi vs the 8psi, or is that small fluctuation acceptable.

But still wouldnt account for the weird datalog on the MAP sensor...

Any input...am i reading something wrong in my logs?

LOG HERE

Thanks all!

[jamesm]

are you using the stock map sensor? it has limited range, mine maxes out around 5psi.

[Calum]

^^That was my first thought to.

[gdrider77]

Originally Posted by jamesm

are you using the stock map sensor? it has limited range, mine maxes out around 5psi.

3bar map sensor.

[jamesm]

Originally Posted by gdrider77

3bar map sensor.

maybe it's not scaled properly? if you can view your rom it's pretty easy to tell.. if the map scale values are 4.834/-2.901 it's still scaled for the stock sensor. you'd probably get a cel though for high or low input if that were the case, but who knows?

[gdrider77]

Originally Posted by jamesm

maybe it's not scaled properly? if you can view your rom it's pretty easy to tell.. if the map scale values are 4.834/-2.901 it's still scaled for the stock sensor. you'd probably get a cel though for high or low input if that were the case, but who knows?

View my rom, do you mean like in ecutek??

[jamesm]

Originally Posted by gdrider77

View my rom, do you mean like in ecutek??

if it's ecutek you can't, unless you know someone with an openflash that can pull it for you. who is the tune from? did the tuner know you were using a different map sensor?

[gdrider77]

Originally Posted by jamesm

if it's ecutek you can't, unless you know someone with an openflash that can pull it for you. who is the tune from? did the tuner know you were using a different map sensor?

Well, i can ask my tuner tomorrow, he is working on the car in the afternoon, so hopefully we can get it all worked out.

[Sellout]

You're in Denver? Atmospheric pressure there is not 14.7. It's more like 12.

But it does look like your MAP scaling has some issues.

[gdrider77]

Originally Posted by Sellout

You're in Denver? Atmospheric pressure there is not 14.7. It's more like 12.

But it does look like your MAP scaling has some issues.

yeah in denver. So would that mean i subtract 12 and not 14.7?

[Sellout]

Originally Posted by gdrider77

yeah in denver. So would that mean i subtract 12 and not 14.7?

Usually. the norm for Denver would be right around 12, but it can go up and down from there. (meaning the atmospheric pressure fluctuates, but generally not much.)

[Sportsguy83]

@gdrider77 , get a boost gauge and compare the ECUtek log with the Gauge.

[gdrider77]

Originally Posted by Sportsguy83

@gdrider77 , get a boost gauge and compare the ECUtek log with the Gauge.

That is what im doing...its crazy. So my boost gauge (aem failsafe) is reading about 10psi. Ecutek is reading 1.25bar, which is about 18psi. SO somehow ecutek and my boost gaguge are about 8psi different?

[Sportsguy83]

Originally Posted by gdrider77

That is what im doing...its crazy. So my boost gauge (aem failsafe) is reading about 10psi. Ecutek is reading 1.25bar, which is about 18psi. SO somehow ecutek and my boost gaguge are about 8psi different?

Formula to convert ECUTek Absolute Bar to PSI:

Abs. Bar *14.5- (Ambien Pressure)

Usually its Abs. Bar*14.5-14.7 (In your high altitude case, that might be ~12 instead of 14.7).

It seems your MAP sensor might not be properly calibrated. I doubt your Boost gauge would be 8 psi off.