Omni 4 bar MAP sensor ROM compatibility settings for USDM Evo 8/9
#32
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Location: New York
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Thanks for the write up, just wondering if it's normal to see a difference between the 4bar log and what the boost gauge is actually showing?
My log is showing that I'm around -8 or so in vacuum at idle but the boost gauge shows -16 and 29psi in the log but 32psi on the gauge.
Using 14.7 in my formula as I'm 80ft above sea level. 88590015 rom id.
Thx.
My log is showing that I'm around -8 or so in vacuum at idle but the boost gauge shows -16 and 29psi in the log but 32psi on the gauge.
Using 14.7 in my formula as I'm 80ft above sea level. 88590015 rom id.
Thx.
#35
Thanks for the write up, just wondering if it's normal to see a difference between the 4bar log and what the boost gauge is actually showing?
My log is showing that I'm around -8 or so in vacuum at idle but the boost gauge shows -16 and 29psi in the log but 32psi on the gauge.
Using 14.7 in my formula as I'm 80ft above sea level. 88590015 rom id.
Thx.
My log is showing that I'm around -8 or so in vacuum at idle but the boost gauge shows -16 and 29psi in the log but 32psi on the gauge.
Using 14.7 in my formula as I'm 80ft above sea level. 88590015 rom id.
Thx.
#36
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Thanks for the reply, the logged value from the OMNI sensor is the -8/-9ish value. The boost gauge seems pretty off so I'll just take the values from the logs from now on for the most accurate reading.
#38
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Not sure if it's coincidence or what, but after installing the omni 4bar and modding my xml to spec, I have having WOT lean issues. I haven't touched my AFR map in quite some time- it was completely dialed in. Before the sensor install, on E85, I was doing the normal 11.5-12.0 AFR at WOT. I did a pull yesterday (first time filling up with E after sensor install), and it was as lean as 14-15.
I had pump in the car during the sensor install and the same thing happened. On my pump maps, I had my AFR tables as low as 8.0 and the richest it would get is 12.0. So I lowered the timing on the pump map and also the boost- no changes to AFR at all.
Any ideas?
Edit, my idle is perfect 14.7-15 and cruising is perfect AFR's. Only WOT is when it leans itself out, usually after 5K.
I had pump in the car during the sensor install and the same thing happened. On my pump maps, I had my AFR tables as low as 8.0 and the richest it would get is 12.0. So I lowered the timing on the pump map and also the boost- no changes to AFR at all.
Any ideas?
Edit, my idle is perfect 14.7-15 and cruising is perfect AFR's. Only WOT is when it leans itself out, usually after 5K.
#40
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No i double checked to make sure it was not on. Was one of the first things that i checked.
Edit: 0 does mean disabled right?
Edit: Question, I have my xml modded with the IAT sensor, but not installed yet (with the correct values transferred from the MrFred BIN file), and the SD patch (not enabled), and the Asynch tables. Could any of those play a role in what's going on?
Edit: 0 does mean disabled right?
Edit: Question, I have my xml modded with the IAT sensor, but not installed yet (with the correct values transferred from the MrFred BIN file), and the SD patch (not enabled), and the Asynch tables. Could any of those play a role in what's going on?
Last edited by lan_evo_mr9; Sep 28, 2009 at 08:09 AM.
#41
Evolved Member
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Adding stuff to your XML does nothing to your ROM. It's only when you change values in ECUFlash and flash them to your ROM are you making changes.
If you have recently switched to E-85 and are going lean, it could be due to the precipitation of the 'injector gunk' that has been metnoined in the past. It may be clogging your fuel filter. If this is what is happening, that precipitate seems to be soluble in gasoline, so running a tank or two of gas may help alleviate the problem.
That is, unless your issue is something completely unrelated and something that you have done to your ROM. Are you sure you aren't running SD or flashed/changed something after installing the Omni 4bar?
If you have recently switched to E-85 and are going lean, it could be due to the precipitation of the 'injector gunk' that has been metnoined in the past. It may be clogging your fuel filter. If this is what is happening, that precipitate seems to be soluble in gasoline, so running a tank or two of gas may help alleviate the problem.
That is, unless your issue is something completely unrelated and something that you have done to your ROM. Are you sure you aren't running SD or flashed/changed something after installing the Omni 4bar?
Last edited by l2r99gst; Sep 28, 2009 at 09:18 AM.
#42
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I'm going to flash my car back to just the necessary mods/definitions needed for the time being to insure that it's not something stupid I did. I will also pull the injectors our for inspection. I'm thinking I did something dumb without realizing it while flashing.
I know for a fact that I didn't enable the SD tables. I never copy/pasted any of the hex values from JSC bin file to mine.
Thanks for the help, I'll see what I can figure out.
Edit: Figured it out, xml snafu on my part. I erased all the SD, Asynch, and IAT definitions, and bingo! I think it was the asynch that was causing my issue since it's headed under the fuel tables and not SD or any other specific table.
On a side note, I checked out the injectors after the flash, and I noticed something not so great. I didn't pull the rail because the upper injector o-rings are starting to dry rot pretty bad (assuming from E85 use), but the o-rings on the bottom of the injectors to the manifold looked perfect. I'm wondering if there are specific E85 o-rings for injectors. The bottom ones were more of a poly material and the uppers are rubber. Wondering if I can get uppers in that other material. Anyone else experience this?
I know for a fact that I didn't enable the SD tables. I never copy/pasted any of the hex values from JSC bin file to mine.
Thanks for the help, I'll see what I can figure out.
Edit: Figured it out, xml snafu on my part. I erased all the SD, Asynch, and IAT definitions, and bingo! I think it was the asynch that was causing my issue since it's headed under the fuel tables and not SD or any other specific table.
On a side note, I checked out the injectors after the flash, and I noticed something not so great. I didn't pull the rail because the upper injector o-rings are starting to dry rot pretty bad (assuming from E85 use), but the o-rings on the bottom of the injectors to the manifold looked perfect. I'm wondering if there are specific E85 o-rings for injectors. The bottom ones were more of a poly material and the uppers are rubber. Wondering if I can get uppers in that other material. Anyone else experience this?
Last edited by lan_evo_mr9; Sep 28, 2009 at 02:11 PM.
#43
Evolved Member
iTrader: (6)
MAP sensors do not know the local atmospheric pressure. To log boost in psig (what all boost gauges show and what people always use to discuss boost values), the conversion formula for the logging program needs to have an offset for your local atmospheric pressure. The general formula for the OMNI 4 bar MAP sensor is:
0.2369*x-b
where b is the local atmospheric pressure. The local atmospheric pressure is affected strongly affected by altitude. For example the pressure at sea level is 14.7 psi, but at 5000 ft, the pressure is 12.2 psi. That's a big difference when you want to log boost. Use this table of altitude vs pressure to determine the offset pressure for your formula:
http://en.wikipedia.org/wiki/Atmosphere_%28unit%29
1 kpa ~= 0.14504 psi
Is the Evo ecu ADC linear (i.e. are the mut readings 256 * voltage / 5.0)? Assuming they are, I have
P_psi = 0.2340x + 0.5043
Absolute pressure of course.
I checked twice and those numbers seem to match the reference values from omnipowers's table. 1.168 volts => 1 bar => 14.50 psi.
d
EDIT: corrected arithmetic
Last edited by donour; Oct 11, 2009 at 06:33 PM.
#44
Evolved Member
iTrader: (115)
I just did the derivation from Omnipower's docs and I have slightly different coefficients. One thing I noted was that 100 kPa / 1 bar is not the same as 1 atmosphere.
http://en.wikipedia.org/wiki/Atmosphere_%28unit%29
1 kpa ~= 0.14504 psi
Is the Evo ecu ADC linear (i.e. are the mut readings 5.0/256 * voltage)? Assuming they are, I have
P_psi = 0.2340x + 0.5043
Absolute pressure of course.
I checked twice and those numbers seem to match the reference values from the omni's table. 1.168 volts => 1 bar => 14.50 psi.
d
http://en.wikipedia.org/wiki/Atmosphere_%28unit%29
1 kpa ~= 0.14504 psi
Is the Evo ecu ADC linear (i.e. are the mut readings 5.0/256 * voltage)? Assuming they are, I have
P_psi = 0.2340x + 0.5043
Absolute pressure of course.
I checked twice and those numbers seem to match the reference values from the omni's table. 1.168 volts => 1 bar => 14.50 psi.
d