Custom os tuning questions

[cyipher]

I’m going turbo this year and I changed over to COS 3 in Efilive and now im lost. They talk about Semi open loop and now tuning via PE or boost ve. Help me out here, I’m running O2 sensors still and I’d like to use them but it seems like I would be better to disable PE altogether and just tune off of the ve and comanded tables. Also in COS 3 they now change to commanded rpm vs map which is blank from the re-flash, should I populate this table from the previous commanded table (if thats possible)?

[joeygc5]

You need to take the values in the 105kpa column and copy them exactly to the 105kpa column in the boost VE table. Then you have to fill in the remaining VE boosted table cells with #'s. Once your over 105kpa your basically using the VE # as the actual fuel value for fueling. So if your logging and the air/fuel is 13.5 take the cell value and multiply it to get your desired (11.5'ish) value.

In semi-closed loop the O2 sensors are used still to regulate to the stochiometric value you have listed in the table B3647. The long term fuel trims are no longer used (disabled), so monitor short term fuel trims to see what the VE table is doing. I disable PE completely and then modify the Boosted VE table for my desired air/fuel levels.

[darcy]

There are a few tables that are blank when first going COS, have a read of the Custom OS Tutorial in the TuneTool - it covers of setting up the new tables.

One approach to fuelling is to use B3647 to control up to 105kPa, then use PE as BE above say 120kPa, as described by johnv in THIS (http://forum.efilive.com/showthread.php?22479-Q-on-boost-VE-table&p=190246&viewfull=1#post190246) post.

[picnic_george]

Also in COS 3 they now change to commanded rpm vs map which is blank from the re-flash, should I populate this table from the previous commanded table (if thats possible)?

There are a few tables that are blank when first going COS, have a read of the Custom OS Tutorial in the TuneTool - it covers of setting up the new tables.
The tutorial had commanded set at 1 all the way until 100kPa then richened it up. You're saying that is correct? Unless I'm missing another commanded fuel table or multiplier somewhere, that sounds dangerous to run 1 EQR(14.7:1) at 70kPa at 5000 rpms. I set the commanded to where I think it should be, not at 1 as explained in the tutorial.

[joecar]

+1 set B3746 to sensible values, especially if PE is disabled...

( I would also leave PE enabled )

[ please, don't blindly follow the tutorial... think about what is going on and how it works ]

[joecar]

In OL, the cells in B3647 set to EQR 1.00 will be trimmed on using STFT (even if CL/trims are disabled)... this is called Semi-Open Loop (SOL);

during tuning you have to watch out for this (do not use EQR 1.00 in B3647... use 0.99 or 1.01 instead).

[picnic_george]

+1 set B3746 to sensible values, especially if PE is disabled...

( I would also leave PE enabled )

[ please, don't blindly follow the tutorial... think about what is going on and how it works ]That's why the question was asked. And that is why I didn't do it haha. I think they may change that or note the the tutorial so someone doesn't miss that.

In OL, the cells in B3647 set to EQR 1.00 will be trimmed on using STFT (even if CL/trims are disabled)... this is called Semi-Open Loop (SOL);

during tuning you have to watch out for this (do not use EQR 1.00 in B3647... use 0.99 or 1.01 instead).Even with the CL temp set to max and STFT disabled? Not that there is an issue with that at all, it's definitely great info to know(remember). Just wondering why it does that when it's set up not to...

Also does the commanded table for ethanol B3649(maybe)??? need to match b3647?

[joecar]

...
Even with the CL temp set to max and STFT disabled?
...
Yes, even with CL disabled (CL temp set to max), LTFT disabled, and STFT disabled.

SOL is enabled in OL for any stoich cell in B3647 or B3649.

[joecar]

B3647 and B3649 do not necessarily have to be the same...

[cyipher]

Yes, even with CL disabled (CL temp set to max), LTFT disabled, and STFT disabled.

SOL is enabled in OL for any stoich cell in B3647 or B3649.

so whats the difference in SOL and CL with LTFT disabled then?

[cyipher]

Also is there a delay for SOL to enable?

[joecar]

so whats the difference in SOL and CL with LTFT disabled then?
CL with LTFT disabled = Closed Loop with no trims.

SOL = Open Loop with STFT on stoich cells in B3647/B3649.

[joecar]

so whats the difference in SOL and CL with LTFT disabled then?


CL with LTFT disabled = Closed Loop with no trims.

SOL = Open Loop with STFT on stoich cells in B3647/B3649.The implications of this are as follows:

CL with LTFT disabled:
- this is still CL mode,
- LTFT trimming has been disabled,
- STFT trimming has been disabled (either explicitly via B4206, or implicitly via LTFT trimming being disabled, depending on COS),
- OLFA tables B3647/B3649 are not active (because we're in CL mode),
- when you enter PE mode, the PE table B3618 is the only active fuel table;

SOL:
- this is OL mode,
- STFT trimming is enabled on stoich cells of B3647/B3649,
- OLFA tables B3647/B3649 are active (because we're in OL mode),
- when you enter PE mode, the active tables are B3618 and B3647/B3649, so commanded fuel is the richest of the current cell in those tables;

[joecar]

Note: for those COS's that have B4206, SOL may still function even when B4206 is disabled, you have to check this (by viewing what the wideband shows).

[picnic_george]

I R CONFUZED. If the o2 is correcting fuel, then it's the same thing isn't it? LTFT disabled and zerod, there will be no overall fuel correction, other than the o2s pulling the a/f mixture to stoich. Correct? Isn't that exactly what STFT enabled, LTFT disabled is doing too?

[picnic_george]

Is it just because that's the way the COS is? It would seem that disabling the LTFT on a non-COS would yield the same results. Am I correct? Is the wording what changes? I think that's where the confusion is, maybe lol

[joecar]

I R CONFUZED. If the o2 is correcting fuel, then it's the same thing isn't it? LTFT disabled and zerod, there will be no overall fuel correction, other than the o2s pulling the a/f mixture to stoich. Correct? Isn't that exactly what STFT enabled, LTFT disabled is doing too?SOL does the same as B4206=enabled, but SOL is regardless of B4206 (some of the COS's don't have B4206).

[joecar]

Is it just because that's the way the COS is? It would seem that disabling the LTFT on a non-COS would yield the same results. Am I correct? Is the wording what changes? I think that's where the confusion is, maybe lolYes, SOL is a feature of the COS's...

SOL is enabled purely by B3647/B3649 cells being stoich, regardless of B4206 (for the COS's that have B4206).