Good stuff!

OK I have the early beta of the Santa release, which includes all the features of the AC Idle up release plus MAT correction! Initial results look promising, but they do require careful tuning, because it changes the balance for the closed loop PID.

A picture of the settings menu:
https://www.miataturbo.net/attachmen...ine=1320749806

Initial semituned results here:
http://img.photobucket.com/albums/v6...correction.png

The idle duty will really rise with increased MAT, but I noticed that the range of valve motion stayed more or less the same. Meaning PID is not exerting more effort at higher temps, and that the MAT correction is actually correcting for the less dense air.

Subjectively, the idle felt more stable at high temps. I turned off the A/W intercooler pump and let it heatsoak to 160F, but idling was rock solid. Killed the engine, started it up, no heatsoak starting issues. I still need to tune it because at high temp, the correction was a bit too much for the no-AC idle, and dragged the idle 50 higher than the target. But honestly, I couldn't really tell, it only came up in the scatter graph.

Great job Santa! ;)

No problems. Santa always like to please ;-)

I'm keen to work with someone who is in the colder climates (Greg is near the equator) so that we can tune/review impact to what happens when apply this firmware in those locations - any volunteers??

G

Just wanted to add that this works a charm. It was the only way we could get a stable idle on a FS-car (supercharged single.cyl, no flywheel).
We also mapped the VE curve from start to finish and positioned our idle rpm targets in the middle of downward VE slopes. If the idle valve overshoots target-rpm the VE drops away, adding a natural tendency to return to the target RPM. Lower then target RPM->VE increases. We would let it hop between a couple of these set points instead instead of ramping it down smoothly.

Interesting! I try to maintain downward spark slope and keep the VE pretty flat. Won't leaning it out above target create a tip in lean spot?

im in buffalo, new york (snow belt) area we'll be cold here pretty soon. ill try it out in the colder temps . where do i get the firmware? ive got all the time in the world to try it out...lol.. is it the same 3.1.4 on msextra?

Finally got to try the clutch/neutral closed loop lockout option today... wow, very nice! Much more stable feeling during low speed "parking lot/traffic light" conditions. It does however highlight the need for accurate calculation of the idle valve value during CL idle entry. "Last known good value plus dashpot" needs to be improved...once that is licked and you start closed loop idle with the correct idle duty...we will be very close to seamless...

http://img.photobucket.com/albums/v6...llockout-1.png

Crap.. that should have been VE dips.
The VE dips were not tuned in, we just used the normal intake and exhaust resonances. Spent quite of bit of time building the VE curve by mapping the engine every 100rpm or so to a constant Lamdba. The end effect is similar to building fueling and spark slopes but more effective.

explain to me this clutch/neutral lockout.

I'm intrigued. Are you saying that the motor has VE peaks and dips if you zoom in from say, 700-1500 RPM?

You can plod along in gear and it won't enter CL idle at all, never, no mater even if you go off throttle completely and essential the idle is pulling the car along - great for traffic cruise etc.

Avoids the rpm climb when you slam the clutch in, as the pid hasn't been fighting the load, it just casually enters CL pid and continues to idle normally.

A very simple od that took no time for me to code and make work.

You need to wire the clutch switch to pe0 / flex input.

G

PS - I sent you a PM and you've flatly ignored me, wassup with that?

isnt this what the RPMdot part of the lock settings are for? or is this another part of the code that ms2 doesnt have? MS3 has an adder to change the RPMdot lockout setting when the a/c is on.

if anything when this happens there would be an idle droop not a climb, as your chugging along at say 1200 rpm in 5th gear, then CL would activate and would want to lower the idle to your target and start closing the valve. Then when you hit the clutch you send the rpms to stalling range...I fought this until i tuned my settings correctly. It took no time at all to make it work :)

Jup.

No, RPMdot lockout exists, but obviously there is nothing related to a/c idle up as that is my code - and I could add that if needed. From what I've heard and seen myself, this RPMdot lockout doesn't solve for all problems.

No, the scenario without this mod is ... you are in 1st gear, idling along, you come to a slight incline and the idle is dragged down to 800rpm, the PID code responds and opens the valve more to compensate and in turn raises idle due to the load, and cycle repeats - with the valve opening all the time to compensate.... eventually, bang you slam down the clutch (to avoid hitting the car in front, or stall) and boom the rpm spikes until the PID catches it etc.

With this mod, none of the above happens.

G

Could you describe roughly how it looked - i.e. like how many peaks and dips you saw from 700-1500, and how tall/deep they were?

actually it does in the code, but no idle up adder that you havent added yet. ;)

can never think of a time i'd ever need this code function. Correct me if I'm wrong but this is just preventing an idle spike if you happen to be costing without throttle while the idle code is enabled up a hill for some reason and then hit the clutch in?

Hmmm now you have me interested. Could you post a new thread regarding the tuning process you went through to map your idle area? I'm sure it'll be quite an interesting discussion and deserves its own thread. Right now I do try to make a valley but to be honest the methodology is kind of hit and miss. :facepalm:

Spot on! If that's never happened or the spike doesn't bother you, than sure this mod isn't for you... but a few folks have asked for it and I too see how ti keeps idle silky smooth.... and it costs nothing to wire up and enable.

Also, I think it makes tuning a little easier (I guess)....

G

does it utilize the same input as launch control, or do you have the split the input?

Uses the same but doesn't impact each other.... Never used against each other anyway....

G