2013 F150 3.5 Eco Boost Limiters

For some reason, at WOT this truck still hits the Combustion Stability Limit and the Turbo Fmem. I raised the Combustion Stability Limit table to 260 Kpa & 1600 ft lbs (that made no diff over the stock values) Also raised the LSPI Reduction > FMEM table is steps all the way to 16 with no changes to the Turbo Fmem coming on in the scanner at WOT.


I also disabled the Combustion Stability Limit & Turbo Fmem in the Torque Ratio Configuration tables.


Also hitting TQ Reduction < Driver Demand under Throttle Angle Source at WOT.


Truck is stock with 305/55/20 tires using 94 octane fuel, What am I missing?

Why is some of the text green?




Russ Kemp

Any luck? I hit the combustion stability limiter on my wife’s 14 also and not sure what is the issue. Still very green with the ecoboost I’ve been doing the coyotes for about 2 years.

Not yet. Sent an info log to support and they will see if there are anymore limiter tables to add.

Russ Kemp

Quote:

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Originally Posted by Russ K

Not yet. Sent an info log to support and they will see if there are anymore limiter tables to add.

Russ Kemp

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you helped me a bunch 15 years ago with some ls1 tuning.

try this, you might want to disable the 3334 master switch (try it just to see)

I will add that you need log all the "source" "limit" "TR" pids.

Thank you so much. I'll try your changes this week. And will log the source limit tr pids.

Russ Kemp

I looked at this for a bit last night but wasn't too sure. I'm not as well informed on the inner workings of Ford software, but I did read that Ford changed some things in the torque limiting arbitration as they prepared for 2nd generation Ecoboost. So I'm not sure if these exist in your file, but I found them very useful for removing limits for the 2nd gen Ecoboost. I didn't see them in your file.

Attachment 103347

Those tables are not in this truck. What year are those tables from?

Russ Kemp

A 2018 Ecoboost Raptor.

I've been having this same issue on my Mustang as well, I can seem to still tune around it... But it feels like the combustion stability limit is still holding me back.
I have CLIP/ADD mode off too, didn't make any difference for me.

I feel as if something isn't quite right with either the existing combustion stability parameters, or there's something missing.

Any update?

Getting the truck back on Friday to test the updates that LastPlace did for me.

Russ Kemp

Thank you for the update, hoping all will be good

Well, that tune corrected the "Turbo FMEM". But still hitting the "Combustion Stability Limit" and the "Torque Reduction > Driver Demand". But now hitting "Engine Ind Torque Limit". Finally, the truck falls out of power enrichment around 4900 rpm in 3rd gear.

To fix the power enrichment, I returned the ECM 9692 table to stock. To correct the "Engine Ind Torque Limit", I added 20% to the ECM 44779 table. I tried increasing the 2 bottom rows of the Driver Demand table, but it did nothing for the boost or throttle limiters and caused the "Engine Ind Torque Limit" again. So I lowered the 2 bottom rows of the Driver Demand by 10% to correct the "Engine Ind Torque Limit".

Attached is the last tune & log from today. Thanks for the help.

Russ Kemp

Quote:

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Originally Posted by Russ K

Well, that tune corrected the "Turbo FMEM". But still hitting the "Combustion Stability Limit" and the "Torque Reduction > Driver Demand". But now hitting "Engine Ind Torque Limit". Finally, the truck falls out of power enrichment around 4900 rpm in 3rd gear.

To fix the power enrichment, I returned the ECM 9692 table to stock. To correct the "Engine Ind Torque Limit", I added 20% to the ECM 44779 table. I tried increasing the 2 bottom rows of the Driver Demand table, but it did nothing for the boost or throttle limiters and caused the "Engine Ind Torque Limit" again. So I lowered the 2 bottom rows of the Driver Demand by 10% to correct the "Engine Ind Torque Limit".

Attached is the last tune & log from today. Thanks for the help.

Russ Kemp

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Your actual load is limited by your Torque tables causing throttle Angle source to be "TQ red. < Driver Demand" and as a result Driver Demand Limit Source will be "Comb. Stab. Limit"
After this is corrected your desired Load will be limited by your LSPI Tables that are set to 1,85 at present.

Quick and dirty solution is to increase just the Inverse tables in the concerned areas to aim for higher load.

Set ECM 44779 back to stock, as you are not changing the rotating and oscillating masses of the engine it will negativly influence your TQ-calculation.

Attachment 104029Attachment 104030

G-Town-GT, thanks a lot for the tips. I will try them next week and let you know how it works.

Russ Kemp

Tried those changes, didn't seem to affect the limiters. Tune & log #67 has the inverse torque tables raised. Tune & log #92 has the stock torque inverse tables, and some other changes. Note that these changes don't seem to affect the limiters, or Map Kpa.

Also tried raising the torque inverse tables by another 10-20%, that just caused the engine to surge while cruising and didn't affect the limiters or Map Kpa.

Russ Kemp

I'm my current tune, what I did was use the torque inverse calculator, take top load row and copy it back one row, then increase the top row load by 25% and the toque values by the same 25%, then recalculate the inverse load. Did that for all mapped points.
That let me hit higher air loads (now being limited by LSPI tables), but it's still in combustion stability torque control.

Like I said, I can kind of tune around it, but it still feels like it's holding back.

Edit:
Is it in "combustion stability" limit simply because the driver demand is higher than the matching cells in the engine torque tables and it just can't get a higher load to support that driver demand?

If that's the case, then it being called "combustion stability" is a bit misleading, but I suppose the strategy is reusing it for a torque limiter.

Not sure I understand what you're saying. But if you use the calculator & increase the engine torque tables, the inverse tables are then lowered.

G-Town-GT said to raise the inverse tables (that didn't help with my limiters)

Russ Kemp

One table references the other, they really need to agree.
You could modify just the inverse table, but it can have undesirable effects... Muck up fueling, at least that's been my experience with modifying one but not the other.
I'm also on a 2.3 Mustang, so my ECU strat is different than any of the other EB engines, even the 2.3 Focus RS.

Here's one of my stock torque tables:
Attachment 104259

Here's what I have now:
Attachment 104260

I’m going to try to lower the torque tables by 20%, which will raise the inverse tables.

Russ Kemp