ECMlink Omni 5 bar MAP sensor ECMLink settings needed

[deboelduro]

Just bought a Omni 5 bar to replace my 4 bar that I’ve had for years. Wanted to run more boost so. What settings would I input. On ecmlink

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[1990TSIAWDTALON]

I have been hunting for the correct values and have finally come to the conclusion that it would be easiest to just contact them directly.

Contact | omnipowerusa.com

When I look at the Omni 3 bar settings they are +9.132v down to -0.020v
The Omni 4 bar settings are +11.963v down to -0.039
SOOO....if I did the math right, you can try +14.794v for the high limit and -0.058v for the low limit.
I emailed Omni with the question, we will see if I get an answer close to my math
Marty

 

[1990TSIAWDTALON]

So Bob, from Omni, got right back to me with these specs. I think the negative #'s are for the low setting (vacuum) and the high settings are for boost.
One thing to remember about MAP sensors is that when you get a 4 BAR sensor, it reads negative also to 1 bar at least. It is something some people overlook and think 4 BAR = good to 56psi which is wrong, only good to about 42ish. I know, I run one. I have a 5 BAR Omni sensor also since I run over 42lbs of boost on the stick car but it isn't installed yet.
Here is his attachment he sent me back.
Marty

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[Michael Wucher]

So Bob, from Omni, got right back to me with these specs. I think the negative #'s are for the low setting (vacuum) and the high settings are for boost.
One thing to remember about MAP sensors is that when you get a 4 BAR sensor, it reads negative also to 1 bar at least. It is something some people overlook and think 4 BAR = good to 56psi which is wrong, only good to about 42ish. I know, I run one. I have a 5 BAR Omni sensor also since I run over 42lbs of boost on the stick car but it isn't installed yet.
Here is his attachment he sent me back.
Marty

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I'm struggling to set up my 5 bar omni. I cant quite seem to get it right. Help would be greatly appreciated

 

[1990TSIAWDTALON]

I did some math between 4 bar and 3 bar Omni sensors and tried to come up with some "user defined" values to try for the 5 bar.
Try 14.790 psi/volt
And -0.058 volts (offset)
You can ALWAYS change it back but give those #'s a try as user defined for the 5 bar map.
Report back please also.

 

[Michael Wucher]

I did some math between 4 bar and 3 bar Omni sensors and tried to come up with some "user defined" values to try for the 5 bar.
Try 14.790 psi/volt
And -0.058 volts (offset)
You can ALWAYS change it back but give those #'s a try as user defined for the 5 bar map.
Report back please also.

would you mind looking me up on facebook if you have one and shoot me a message please. I cannot get this thing to read correctly so ill try and show you what im doing

 

[1990TSIAWDTALON]

Sorry. I absolutely would never join FB. This is about the only media you'll find me on.

 

[danl]

From the Omni spec sheet for the 5 bar:

The offset is 0.6 volts, put this in volts (user defined offset). This is the lowest voltage the sensor will output at 30kpa.

The pressure range is 30 to 500 kpa, or 470 kpa. 470 kpa = 68.1677psi range. The sensor voltage goes from 0.6 to 4.75 volts, or voltage range of 4.15 volts. PSI/volt will be 68.1677psi/4.15volt= 16.43 and matches up with omni's multiplier factor. Put 16.43 volts in volts/psi (user defined scale).

You can verify this using the transfer function in the spec sheet.

 

[Michael Wucher]

From the Omni spec sheet for the 5 bar:

The offset is 0.6 volts, put this in volts (user defined offset). This is the lowest voltage the sensor will output at 30kpa.

The pressure range is 30 to 500 kpa, or 470 kpa. 470 kpa = 68.1677psi range. The sensor voltage goes from 0.6 to 4.75 volts, or voltage range of 4.15 volts. PSI/volt will be 68.1677psi/4.15volt= 16.43 and matches up with omni's multiplier factor. Put 16.43 volts in volts/psi (user defined scale).

You can verify this using the transfer function in the spec sheet.

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Here is what I’ve used. Does that look right?

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[Michael Wucher]

From the Omni spec sheet for the 5 bar:

The offset is 0.6 volts, put this in volts (user defined offset). This is the lowest voltage the sensor will output at 30kpa.

The pressure range is 30 to 500 kpa, or 470 kpa. 470 kpa = 68.1677psi range. The sensor voltage goes from 0.6 to 4.75 volts, or voltage range of 4.15 volts. PSI/volt will be 68.1677psi/4.15volt= 16.43 and matches up with omni's multiplier factor. Put 16.43 volts in volts/psi (user defined scale).

You can verify this using the transfer function in the spec sheet.

Just tried those settings, car has no throttle response and struggles heavily to idle

 

[danl]

There is a thread about the Omni 5 bar on the ECMLink forum. There is also information on configuration custom sensors on the how to wiki.

 

[danl]

linearitems [ECMTuning - wiki]

www.ecmtuning.com

I would expect to see linear boost as sensor type in drop down. Also I saw a post where someone’s car was broken, then they added an Omni 5 bar. Not sure if that was you, but if it is, it’s possible something else is broken and the map sensors are fine.

 

[Michael Wucher]

linearitems [ECMTuning - wiki]

www.ecmtuning.com

I would expect to see linear boost as sensor type in drop down. Also I saw a post where someone’s car was broken, then they added an Omni 5 bar. Not sure if that was you, but if it is, it’s possible something else is broken and the map sensors are fine.

It was possibly me. Car has been running super super rich AFRs and I thought the MAP was culprit

 

[danl]

I think you need to resolve your first issue before adding complexity with a 5 bar MAP.

Try to find a known good GM 3 bar MAP if you have data proving the MAP is the issue. Otherwise find and fix your original problem. The Omni sensors can be hit and miss reliability wise. The non Chinese GM are known to be more reliable and have better resolution.

 

[schafer240]

Anyone else figure the input values?

I just emailed Bob at Omni, see what he says.

This is what I have figured out so far but it means pretty much nothing. Had the car running but it the MAP numbers where off about 1-2psi at idle of -20psi and off 4psi at 0 psi

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My math

When you do basic math to calculate the psi/v it equals

.6V - 4.75V = 4.15V
500kpa - 30kpa = 470kpa --> 68.16 psi

68.16 psi / 4.15 = 16.426 psi per Volt

So the multiplier seems to be correct.

Solving the offset is an unknown to me at this point.

The offset is calculated in DSMLink by voltage.
What is the -5.504 numbers units? Obviously it's not volts being a 0-5v sensor that reads 4.75v max.

I should also add that I tested the sensor keyed at 0 psi and the voltage was 1.095 Volts, could that be the correct offset?

My only concern is the other setting in link for the 3/4 bar are super low, almost 0.

Also the DSMLink preset multiplier and Omni numbers don't match up for the 3 / 4 Bar Sensors, anyone have any idea on this?

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[Michael Wucher]

Anyone else figure the input values?

I just emailed Bob at omni, see what he says.

This is what I have figured out so far but it means pretty much nothing. Had the car running but it the map numbers where off about 1-2psi at idle of -20psi and off 4psi at 0 psi

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My math

The multiplier is 16.426, yet when you do basic math to calculate the psi/v it equals

.6V - 4.75V = 4.15V
500kpa --> 72.52 psi

72.52 psi / 4.15 = 17.4746987952 psi per Volt


The offset is calculated in dsm link by voltage.
What is the -5.504 numbers units? Obviously it's not volts being a 0-5v sensor thar reads 4.75v max.

Also the dsm link preset multiplier and omni numbers don't match up for the 3 / 4 Bar Sensors, anyone have any idea on this?

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I appreciate the reply, props to you for taking the time to do all that math . Save yourself the headache and buy an AEM 5 bar. Trust me, you won’t regret it!!

 

[schafer240]

Lol I just paid $240 for the Omni one shipped, I'm committed.

I did find out playing around with link that the main issue to get the sensor to zero out isn't the numbers on the inputs page but rather the scale on the data log page when you select your high and low values. The 30kpa or 4.35psi throws the scale off, it needs to be changed. So I just manipulated it until the map sensor read 0 with the ignition off.

That's the best start information I have so far.

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Also to add, it strangely seems to run the best on the 4 Bar Settings

 

[curt-s]

Old thread but pertinent..
1) how reliable are their 5bars
2) what is the bit size of the ADC used to translate the voltage in either a 1G or 2G ECU? that will absolutely affect voltage readings and even a minor math problem there would result in drastically different boost pressures being assumed

 

[steve]

2) what is the bit size of the ADC used to translate the voltage in either a 1G or 2G ECU?

1G is 8 bit 0-5v full range.

 

[schafer240]

Old thread but pertinent..
1) how reliable are their 5bars
2) what is the bit size of the ADC used to translate the voltage in either a 1G or 2G ECU? that will absolutely affect voltage readings and even a minor math problem there would result in drastically different boost pressures being assumed

The sensors are good quality and frequently used in the Honda world.

Problem is DSMLink doesn't have a quick selection for this sensor and the scaling math numbers that should work don't.

Also I emailed Omni a few times and they never got back to me.

I also posted this in the past to the DSMLink forums and got some answers but ended up not working so I ditched it for the proven AEM 5 bar.

 

[FIBA M - EC17PSE]

Omni sensors suck and fail regularly, even ECMTuning say they have a hard time getting a hold of them as they fail. I had a new one go bad just from sitting doing nothing!!

Gave up on them and the price for a basic GM sensor really

Went to a full motorsport Stainless sensor and 5 bar also and works a charm. People need to stop using Omni as they do not care about you or their products at all.

 

[curt-s]

That's the thing.. I'm running 26-27 psi but on a 3 bar GM map. To me, that's cutting it too close to the maximum.
Kind of like how we don't really want to run injector duties above 80%, a 3 bar map is only good for about ~28psi of boost.
So i'm looking for a bigger sensor but saying "just go 5 bar instead of 4 bar" isn't always the answer because it depends on the ECU's ADC resolution whether that 5 bar gets you max pressure but at the expense of the finer resolution inbetween 0 and max.

If we're talking 0.5V -> 4.5V range, that's only 4V. An 8bit ADC gives you 255 possible values. That seems like a lot but it's really not, especially if that 4V has to cover absolute vacuum all the way up to 73.5psi absolute pressure (<14.7 being vacuum of varying degrees).

Should I have my math right:

Every bit in a 8bit ADC with a 5 bar sensor that has a 4V range represents 0.0157V and, conversely, about 0.288psi. Every 54.4mV out of the sensor represents 1 psi.

A slight offset in the sensor's ground reference can represent an entire psi worth or more. The larger the map, the more millivolts represent each psi. However, you're still limited by the resolution of your ADC to turn those millivolts into psi that the ECU will use in calculations.

 

[curt-s]

1G is 8 bit 0-5v full range.

Any idea if they went 16 on 2G since they're actually supporting a MDP and the part cost probably came down to similar to 1G?

 

[We're on Boost]

Any idea if they went 16 on 2G since they're actually supporting a MDP and the part cost probably came down to similar to 1G?

I just looked at a couple of 2g logs, the MDP raw voltage logs. The MDP logs in steps of about .02 volts per step, just like 1g.
5volts/.02 = 250 steps available (approximately, would be 255 with more places on the volts per step number)
So that's still 8 bit.

That's the thing.. I'm running 26-27 psi but on a 3 bar GM map. To me, that's cutting it too close to the maximum.
Kind of like how we don't really want to run injector duties above 80%, a 3 bar map is only good for about ~28psi of boost.
So i'm looking for a bigger sensor but saying "just go 5 bar instead of 4 bar" isn't always the answer because it depends on the ECU's ADC resolution whether that 5 bar gets you max pressure but at the expense of the finer resolution inbetween 0 and max.

Yeah, actually for the case you are describing, it sounds like you could use a 3.5 bar sensor, in which case you could put a proper AEM stainless 3.5 bar sensor on it.
That's what I did, after running the AEM 5 bar for a few years.
I was "ok" with the AEM 5 bar but I noticed that my AFRatioEst logs had spikes in the curves, which bothered me a little.
So I changed to an AEM 3.5 bar, and now, no more spikes in AFRatioEst!

The AEM 3.5 bar is about 12.51 psi per volt which is slightly more coarse than an Omni 4-bar (because the AEM is only using 4 volts of the range).
But the AEM is probably going to be a lot more reliable.

(The Omni 4 bar is about 11.96 psi per volt)

 

[miliman13]

@curt-s
I recently covered a EBay generic 4-bar in my build thread.

I compare it to the OMNI and it’s purdy good for being so cheap at least if it goes bad it’s like 15-20 bucks depending were your source it.

Also working on a dual MAP controller so incase one fails you keep running.

Post in thread 'Red5.'
https://www.dsmtuners.com/threads/red5.491289/post-153960188