Feature enhancement for MAT-Based Timing Retard

[zmanco]

MAT-based Timing Retard is an essential tool for boosted engines, especially on the track in the summer. But this also results in timing retard at idle and low RPM in stop/go traffic conditions as well as hot restarts where it's not needed nor wanted.

Would it be possible to add start and end RPM values to blend in timing retard as is done for Time-based Accel Enrichment?

[ol boy]

that might help with my set up also. or have a min and max map value too.

[Nitroking]

MAT-based Timing Retard is an essential tool for boosted engines, especially on the track in the summer. But this also results in timing retard at idle and low RPM in stop/go traffic conditions as well as hot restarts where it's not needed nor wanted.

Would it be possible to add start and end RPM values to blend in timing retard as is done for Time-based Accel Enrichment?

Hi, good idea. Instead of 2 rpm limits you could have one variable, "Minimum MAP for MAT Timing Retard".. So if you put 80Kpa, then it will start retarding only if MAP is more than 80Kpa meaning idle an cruising will not be affected..

[jamies]

...and the possibility of negative numbers, ie MAT based timing advance/retard

[zmanco]

Instead of 2 rpm limits you could have one variable, "Minimum MAP for MAT Timing Retard".. So if you put 80Kpa, then it will start retarding only if MAP is more than 80Kpa meaning idle an cruising will not be affected..

I thought about that but worried that this could become a noticeable change under some conditions. Assume MAT retard is 5 deg. As soon as MAP increases beyond 80 kPa in your example, timing will immediately be retarded 5 deg. That would be rather noticeable, hence the suggestion to transition over some range. I suppose it could be over a MAP range instead of RPM, in fact that probably makes more sense as pre-ignition is a function of load ...

[Nitroking]

Same will happen if you use RPM. You will notice it. If MAT is 70C and at that cell you have -5deg, once you go more than 3000rpm say, you will notice it.. Same with MAP, you will notice It when MAP goes over 80.. The thing is that when in 80Kmap you will be making enough power to feel it less than when you are cruising at 3000rpm.. Plus MAP is the criteria you mentioned at your first post. High MAP (Load) is the dangerous zone for knock, high rpms with little load is not that dangerous..

[pigga]

MAT-based Timing Retard is an essential tool for boosted engines, especially on the track in the summer. But this also results in timing retard at idle and low RPM in stop/go traffic conditions as well as hot restarts where it's not needed nor wanted.

Would it be possible to add start and end RPM values to blend in timing retard as is done for Time-based Accel Enrichment?

Hi A workaround for this could be to use "Idle Advance settings"

idle.jpg

In this case the Controller will use different Idle ignition advance settings as soon as the idle conditions are met.
But you'll have to set up the required idle advance separately:

idle_rpm.jpg

To my experience MAT based timing retard will not influence the idle advance settings. Please correct me if I'm wrong.

[zmanco]

I already use Idle Advance to help stabilize idle around the target RPM by adding progressively more advance as RPM drops and reducing a small amount as it rises. But even if I wasn't already using it, I'm pretty sure MAT-based timing retard is additive (subtractive?), so would still affect the advance at idle.

[pigga]

Hm.
Will this also be the case if you choose Idle advance as "set value"? Maybe the developers can give more information?

[krisr]

I made a suggestion in the 1.4 alpha thread for ms3 that I'd like to see this become a tunable table rather that a 2 point curve applying to total correction. Not sure how this would apply to the specific idle advance function tho. Could be something that both codesets could share hopefully.