Sometimes Losing MPOP Briefly

[CCS86]

Can anyone explain this phenomenon?

It's pretty rare, but sometimes at WOT, after I have already reached 100% MPOP, it will blend back to MP10 briefly:

Losing OP.jpg

The VCT Schedule Mode stays locked to OP.

MP10 is only used in my Optimal Stability and Emissions Reduction distance tables.

It's not a huge issue, since the cam angles don't deviate much from my OP angles, but I'd like to understand why I lose control like this.

[blackbolt22]

I would think the cam angles are the closest to MP10 in this moment... My stock car blends to MP7 and 8 sometimes as well and I believe it causes a small power loss.

[bbrooks98]

https://forum.hptuners.com/showthrea...Distance-to-OP

Similar question I asked awhile back. I never quite got to the source of it and it still does it and runs fine, but several thought it was a traction control or limit of some sort.

Bugasu seemed to say it was normal and is related to the bend function. The fact it goes to optimal stability MP10 still makes me think it's a limit but we still haven't fully figured out the Bend functions use yet. Maybe that's the variable to adjust making it not jump to another MP point during a transition when we want it weighted more to OP?

Something to try. Try setting snap to point to zero for MP10 so that it doesn't get much weight priority.

[CCS86]

Still seeing this crop up occasionally. Definitely annoying!

Disabling snap to point for MP7 (the one stealing WOT weight here), has not helped.

Any other ideas?

[bbrooks98]

Still seeing this crop up occasionally. Definitely annoying!

Disabling snap to point for MP7 (the one stealing WOT weight here), has not helped.

Any other ideas?

Maybe try setting the vct for MP7 to something no where close to your OP settings. Looks like your Intake moves from -32 to around minus 20 when it drops which is probably getting close to the MP7 intake cam setting?

Also this was mentioned about the bend:

"There's an overall distance for snap that is separate, I forgot to mention bend.
The idea of the bend table is to reduce the weighting of OP point when enabled but youre not close to it at certain conditions. I.e. say you're on the fuel economy schedule, but maybe not snapped in, this reduces the weight of OP which is off somewhere else. It multiplies the OP distance directly acting on the OP weight. You could theoretically calibrate it higher, but you risk weighing the OP point more heavily than you should when operating in another condition (especially transients).

You should be able to get it to use an OP table during OP conditions by:
1) Enabling the OP Mapped Point
2) Enabling Snap to Point for OP
3) Ensure your OP Bend Distance is 1 / 100% in the RPM ranges you'd expect to be using OP in.

This should get you the heaviest weighting for the OP point posible, provided your cams are actually tracking OP (i.e. minimal cam error).
I dont think there's any other conditions I'm not thinking of right off hand."


he mentions you could try something above 1?

[CCS86]

Thanks man!

The problem with setting MP7 to other angles, is that I'm specifically using it to help blend between MP5 and OP.

I have definitely noticed that during blending, it can show MP weighting that doesn't make sense based on load/rpm, but does make sense because of the total cam angle calculated (if that makes sense). In this case, MP7 is actually tugging on the angles and moving them away from OP definitions.

Here are my settings for snaps and bend. I'm already at bend of 1, but could experiment with higher values.

OP-settings.jpg




[EDIT] Well, scratch that. 1.0 seems to be the predefined limit for bend distance.

[CCS86]

Anyone try changing this table:

[ECM] 38183 - VCT Optimum Power Desired Load % Hysteresis vs. RPM: This is a function that defines the hysteresis of the desired percent load vs. Engine RPM for Optimum Power.

[bbrooks98]

Anyone try changing this table:

[ECM] 38183 - VCT Optimum Power Desired Load % Hysteresis vs. RPM: This is a function that defines the hysteresis of the desired percent load vs. Engine RPM for Optimum Power.

I've lowered it(.60) to go a long with my lowered OP load point (.65). Theory being that it will stay in OP once it goes above the set load and won't return till it goes below the Hysteresis load point.

I know the Bend has a predefined max of 1 which all the cals seem to come with, but I'm curious if it will take a larger number if forced. My cars apart currently so I can't test it. With the traction control shift speed it had a predefined limit of 128 which I used to hit on the dyno, through a recent hptuners update it can now be bumped up to 200mph. So sometimes I think that predefined limit stuff is just on hptuners end and doesn't always mean that's all it will take.

[CCS86]

I've lowered it(.60) to go a long with my lowered OP load point (.65). Theory being that it will stay in OP once it goes above the set load and won't return till it goes below the Hysteresis load point.

I know the Bend has a predefined max of 1 which all the cals seem to come with, but I'm curious if it will take a larger number if forced. My cars apart currently so I can't test it. With the traction control shift speed it had a predefined limit of 128 which I used to hit on the dyno, through a recent hptuners update it can now be bumped up to 200mph. So sometimes I think that predefined limit stuff is just on hptuners end and doesn't always mean that's all it will take.

Interesting. I may try forcing it higher.

Do we know for sure that tables like VCT Optimum Power Desired Load % Hysteresis vs. RPM are meant to be an absolute deactivation point? The term hysteresis could be interpreted other ways.



I have noticed that OP VCT mode seems to be triggered by the Pedal Position table, not the Desired Load table.