Fuel Cut Torque Ratio Questions

[Steven@HPTuners]

Hi Steven, thank you for the explanation!

Yet again, this seems to conflict with LaSota's explanation of the table (Fuel Cut Torque Ratio). He first tells you to change just the Driver Demand entry from 0.95 to 1, and you are done.

Then, 40 pages later, he comes back to the same table and says to zero out every single entry. Citing that "0=no torque reduction, and 1=100% torque reduction".

It sounds like you disagree entirely with this view. Would you recommend leaving this table alone, making slight modifications, or zeroing it out?

Even the description in Editor doesn't seem to match your description:

The Editor description appears to have been messed up when it was moved, and ended up a mix of a correct and incorrect description.

Regardless, my description above still holds true.
A certain amount of reduction is allowed via spark, it will use spark to reduce that amount, and then it'll further reduce it via fuel enleanment and then fuel cut as needed.
You're not going to disable the reduction short of disabling the torque module itself, merely affect how the reduction is achieved.

I'll reupdate these descriptions.

As to how to tune the tables, that's up to you. Zeroing all the fuel cut tables will just say to use fuel enleanment before fuel cut if possible, but it'll be minor as very little torque can be reduced via enleanment. It wont disable fuel cut as a method for reducing torque.

I will say this:
I find too many tuners concentrate on increasing power via trying to sabotage any system that reduces torque, instead of properly allowing the engine to make more torque as needed by increasing torque demands. Work with the torque system and you'll have the benefits of torque control when needed (like during traction control, idle control, etc) vs working against it and trying to tune it like its from the 60s

[CCS86]

Thanks Steven.

I'm with you on trying to work with the systems. Correct the reason a system is intervening, rather than disable the whole system.

[metroplex]

I'm currently experiencing massive spark reduction during WOT shifting. The spark advance can be 24* advance prior to the shift, and then be reduced to -3* during the shift, dragging it out 0.5-0.8 seconds total and it feels like hitting a wall or massive trans slippage when this occurs (but I can tell from engine and input/output shaft RPM it is not slipping). I do not see fuel injector pulsewidth or pump flow being reduced at this point, just spark. The torque source is always "Trans Shift Mod". The controller is TC-1791 and the trans is a 6F55, and the engine is the N/A 3.5L V6

On the TC-1797 with EcoBoost V6 engines and the same 6F55, this spark cut does not occur and I don't even see Trans Shift Mod as the torque source during a WOT shift. So the engine is making almost twice the torque as the N/A 3.5 but isn't getting the spark cut.

Any ideas if this is related to the spark cut ratio table? Shift Modulation 0 or 1 doesn't have an effect. Raising/Maxing the Trans Tq Mgmt has no effect either.

[CCS86]

The Editor description appears to have been messed up when it was moved, and ended up a mix of a correct and incorrect description.

I'll reupdate these descriptions.

@Steven, it has been over 4 years and the description still reads the same in the latest beta version. Can you please correct the descriptions in Editor?

[WesDuenkel]

@Steven, it has been over 4 years and the description still reads the same in the latest beta version. Can you please correct the descriptions in Editor?

Still the same.

[silverbullet08]

I'm interested in your findings here. I'm having the exact same logged symptoms. There appears to be a load limit threshold for the spark cut to occur. If I turn the boost down the car will cut ignition during shift and turning boost up ignition cut goes away giving it this "soggy" shift feel. Tq ratios and sources log the same with boost up or down so seems to be load or accel rate related.
Raising Spark only ratio value "shift modulation" from 0 to any value creates a violent fuel cut and enleanment when "shift mod" source is commanded even at PT and WOT.
When looking at the tune what the ratio authorities are allowed, I am confused as to what tells it to use enleanment vs cut when it will use enleanment occasionally or cut with the same reduction ratio but at different loads.

[GrannySShifting]

@Steven, it has been over 4 years and the description still reads the same in the latest beta version. Can you please correct the descriptions in Editor?

LOL they are not always interested in fixing screw ups for the most part. If its not adding a new vehicle then good luck...

Real fun is mislabled lockup torque converter stuff when UNLOCK makes it LOCK. Super cool LOL

[CCS86]

LOL they are not always interested in fixing screw ups for the most part. If its not adding a new vehicle then good luck...

Real fun is mislabled lockup torque converter stuff when UNLOCK makes it LOCK. Super cool LOL

Exactly my thoughts.

I have dialed back the amount of tuning I do because they seem to have no interest in actually improving the software. They just want to add new vehicles and sell licenses.

Even simple requests of mine:

- When you average a signal in Scanner (when creating a math parameter), it should sample points symmetrically (before and after the point in question) in order to avoid the current behavior, which is to time shift the averaged channel.

Just get sidelined for years now.

Here is what averaging does to that signal: avg.gif

Such a simple fix for a meaningful issue. HPT doesn't care.