Megasquirt owners thread

[Cus]

Sorry, I did get off on a bit of a "it works for me, so it must work for everyone" tangent - VSS does require the input to be enabled in TS, and because you've got an NA6, you'll need to do some "full blown electrical work of huge proportions" ... not really, you'll need a length of wire, a reed switch, some kind of adhesive, some connectors, and about 2 beers to get the job done.

VSS will be called "VSS1" in MLV.

More details here for adding the reed switch to the NA6 cluster: http://mx5cartalk.com/forum/viewtopic.php?f=57&t=65390&start=225#p888328

AFR Error 1 should definitely be in the list, as long as it's being logged by TS. You can check what's being logged in TS by going to "Data Logging" -> "Logging Profiles" on mine the "Default" Logging profile has everything in the right column, so everything is logged. I'm not sure if that's a TS default, or a Cus default. Just put everything in the right-hand column, and you'll be peachy.

[Red_Bullet]

I used autotune in TS early on to get the car car quickly driveable.

Since those early tunes I have used Mega Log Viewer pretty much exclusively for fiddling with VE. I'm not sure what hardware people have ( I'm MS3Pro with SD card attached to a ribbon cable for easy access to SD card.)

I tend now to analyse very large data samples over a few hours road driving, track driving etc. You can open multiple log files in MLV and then VEAL that huge data sample. In statistics the bigger the data sample the more accurate the results.

[ManiacLachy]

2 quick questions for you guys.

Closed Loop Idle Initial Values table, are you based on CLT or MAT? What temperature range? I read that MAT is the way to do it, but currently setup on CLT (the way the base map was). How hot would the intake charge get at idle after a good blast on boost?

And, how are you tuning overrun (low vacuum 10-35kpa)? I read that you shouldn't use VEAL/VEA for it. I have an annoying POP (sometimes loud, almost back fire like) when I apply throttle after coasting a moment, I'm unsure if I need to lean it out or enrichen.

[StanTheMan]

I'm based on CLT currently. But may try MAT....... reason being my IAT is at the intake hole just under the bonnet. which can get heat soak when in traffic. CLT is perhaps a bit more sensible in My case.

I'm just trying to get my head around that.

I Understand most of the closed loop idle. But tuning that table is spinning my head around.

While i have very stable idle right now. & PID gets activated on idle and deactivated when accelerating, but Ive noticed the the PID gets activated while cruising at various RPM's.....for no apparent reason. well there must be a reason. Its probably the dash-pot Adder & table not having been touched.


for anyone who is new like me. That's not saying lachy is included in that....

I found this little article on tuning the Idle valve.
http://megamiata.blogspot.com.au/2016/07/closed-loop-idle-rev-21.html

basic language. Ive learned a lot from that article

[ManiacLachy]

I think I understand the point of the table. When entering CLI, the algorithm will look to that table and open the valve to the set amount (interpolating between the bins), from there the PID algorithm will adjust the valve to open more or less as it needs to to reach the determined RPM. The table is just a point to start from. (this assumes you're set to use the look up table and not last known value).

I don't think my initial value table as good as it could be right now, so I'll re-tune it this weekend. Also, its set to top out at 80C, but my car runs at ~94C, so I'm going to rescale. I'll do CLT for now but might try MAT later.

Stan, to the best of my knowledge, if your CLI is triggering when it shouldn't it's not dashpot or the initial values table, it's the conditions to enter CLI. You may need to ensure that MAP, TPS, RPM, etc thresholds are set lower than what you'd get while coasting/driving.

I'm certainly still a n00b at this, I'm reading as much as I can, learning as much as I can, and experimenting. I've read megamiata a few times over

I come up with new questions every day to research. I'm currently looking into Lag Factors, I suspect a few of mine are way too low. And here's a question I haven't looked into yet, when you add idle PMW % for things such as the radiator fan, this lets the idle valve open a little more, add a little more air to provide more power and overcome the extra load, but what adds fuel to this equation to compensate for the additional air? Do we just accept that we'll go a little lean?

[StanTheMan]

Perhaps my RPMdot Threshold is a litle slow.....

[Cus]

Closed Loop Idle Initial Values table, are you based on CLT or MAT? What temperature range? I read that MAT is the way to do it, but currently setup on CLT (the way the base map was). How hot would the intake charge get at idle after a good blast on boost?

Based on CLT.

This is my initial values table - I "tuned" it by going into "Output Test Mode - Idle Valve" and adusting the value until the engine was at the RPM in the bins, then putting that value in the bins in my table. I've not bothered to tune the temps - possibly why my car idles slightly high until it's good and warmed up

And, how are you tuning overrun (low vacuum 10-35kpa)? I read that you shouldn't use VEAL/VEA for it. I have an annoying POP (sometimes loud, almost back fire like) when I apply throttle after coasting a moment, I'm unsure if I need to lean it out or enrichen.

I manually flatten it out, otherwise I get the pops as well. Both VEAL and VEA will try and add fuel to those bins in the low RPM cells every time, even if you're only in them transiently.

While i have very stable idle right now. & PID gets activated on idle and deactivated when accelerating, but Ive noticed the the PID gets activated while cruising at various RPM's.....for no apparent reason. well there must be a reason. Its probably the dash-pot Adder & table not having been touched.

I've not noticed my Idle triggering when It shouldn't - make sure your CL Idle tables all only go up to 1600RPM or so, that way it won't have any information on how to idle at cruise RPMS, so shouldn't trigger.... (Yup, that's me clutching at straws) I've got "PID" for my idle activation, so I can't find an actual "go into idle when.." setting, it just goes into idle all by it's lonesome.

[ManiacLachy]

Based on CLT.

This is my initial values table - I "tuned" it by going into "Output Test Mode - Idle Valve" and adusting the value until the engine was at the RPM in the bins, then putting that value in the bins in my table. I've not bothered to tune the temps - possibly why my car idles slightly high until it's good and warmed up

Seems we're all on CLT, it'll be interesting to see the differences, I'll give MAT a go once I'm happy with CLT.

Something to keep in mind while using the test mode to find your idle opeining, make sure you turn off Idle Iginition Advance, if you have it setup, or it will fight you and try to bring your RPM down by manipulating spark.

I manually flatten it out, otherwise I get the pops as well. Both VEAL and VEA will try and add fuel to those bins in the low RPM cells every time, even if you're only in them transiently.

By "flatten out" do you mean make them the same value from say 45KPA to 10KPA? Could you post your VE table? Obviously the values will not be of use, but the trends tell a story.

While i have very stable idle right now. & PID gets activated on idle and deactivated when accelerating, but Ive noticed the the PID gets activated while cruising at various RPM's.....for no apparent reason. well there must be a reason. Its probably the dash-pot Adder & table not having been touched.

I've not noticed my Idle triggering when It shouldn't - make sure your CL Idle tables all only go up to 1600RPM or so, that way it won't have any information on how to idle at cruise RPMS, so shouldn't trigger.... (Yup, that's me clutching at straws) I've got "PID" for my idle activation, so I can't find an actual "go into idle when.." setting, it just goes into idle all by it's lonesome.[/quote]
Maybe both of you guys can throw up your Closed Loop settings and we can see if anything jumps out. I don't think mine is activating when it shouldn't. I'll post mine when I'm on the right PC with interenet.

[Cus]

By "flatten out" do you mean make them the same value from say 45KPA to 10KPA? Could you post your VE table? Obviously the values will not be of use, but the trends tell a story.

VEA/VEAL "Lump" Circled, then smoothed. Basically, I use the interpolate button to smoosh it out, figuring the values around it are "correcti-ish" ... once we're out of those cells we're either into CL-Idle, or accelerating again, so if they're a bit wrong, it shouldn't matter too much. At the very least it's not dumping in nearly double amount of fuel it needs to actually run! (low 50's according to my CL Idle table) - this lump seems to keep growing unless you smoosh it out, which I do every few VEA passes.

Maybe both of you guys can throw up your Closed Loop settings and we can see if anything jumps out. I don't think mine is activating when it shouldn't. I'll post mine when I'm on the right PC with interenet.

And here is a link to the Big Version that people can read!

[Cus]

Seems we're all on CLT, it'll be interesting to see the differences, I'll give MAT a go once I'm happy with CLT.

MAT would be more accurate, but harder to tune. Once my car has been sitting for a few moments, MAT starts to rise until I start moving again. If I stop at a red light or a stop sign and wait for a bunch of traffic on a hot day, it will stumble, and sometimes stall if I ease off too easily (I need to input a bit of throttle) ... once it's got some air movement, it behaves itself again. Luckily for me I live out in the sticks, and we only have two sets of traffic lights!

[StanTheMan]

MY PID closed loop settings

Closed loop Idle settings.png

pID gets triggered while gently cruising.
Like 2300 rpm. Map at maybe 40 kpa . I haven't worked out a pattern. just easy cruising.
I've got a indicator on my dash it's an on /off switch
I've also checked this in the logs.

[Red_Bullet]

I'm not using closed loop idle, don't have the need.

[NitroDann]

TPS calibration?

[StanTheMan]

I'm currently using MAPdot. I thought I had a Variable TPS. But I don't.

[StanTheMan]

By the way.

what are we all using for the Idle Valve frequency? in particular for the NA6's

I should find the Thread on Miata Turbo where they recon they confirmed 170 MHz.

the basemap on megasquirt for the NA6 came with some setting close to 400

found it
http://www.miataturbo.net/megasquirt-18 ... ncy-48120/