2.8L M20 9.8:1 stroker build: my 323i reincarnated

[betz]

45 seems ok to me

Ok cool, it was actually pulling like 37 at idle today so I think I've ruled out any major vacuum leaks for sure. If it idles higher too, it would be getting less vacuum.

How did you set your VE tables?

How I set it up or what are they? Why not both lol.

Once I got idle to be good enough, I ran the autotune live feature that comes with the paid tuner studio. Worked super super good. My AFRs at part load, full throttle, up hill, cruising, are all just dialed in it seems. I think my req_fuel might be slightly off because I'm not sure what the pink top S52 injectors lb/hr is on a 3 bar FPR, there's mixed information since OEM is 3.5bar. I have it set as 20 lb/hr. But to my understanding, if you adjust the fuel tables proportionally and you're not swapping injectors it shouldn't matter.

Here is my current VE table. The only values I really edit myself are idle, usually. If my idle is wonky at all the autotune is likely to mess up those values.

[AWDBOB]

How did you set your VE tables?

[digger]

45 seems ok to me

[betz]

Ignition to control idle is thing. If you imagine using a butterfly or other valve to control airflow there is a lag. Ignition is as instantaneous as it gets but the range of adjustment is limited using ignition so still need to have butterfly setup correct. Also don't want too much heat out exhaust with excessive retard

Would that would be Megasquirt's idle advance option? I got the idea to flatten idle ign from browsing through this thread:
https://www.r3vlimited.com/board/for...hread?t=390283

I don't think mine is excessively retarded, relative to those in the thread. I'm at 15 where idle occurs. Before I think it was set into the low 20s.

I'm going to try letting idle advance control idle ignition, and keeping my idle ignition table values flat. This morning I saw the flaw to my methodology since I have it idling higher on start, it was out of the range of my 'valley', and started hunting again. But once it dipped back into the 'valley' when the car was warm, it stabilized.

EDIT: I ended up advancing ignition. With the idle advance, it seemed to idle better after it kicked in. But it would pin it to 30 deg. Advancing the tables, it goes directly to idling well and the idle advance hardly has to do anything. Here are my current tables that are giving me a very nice idle.



And, digger , what vacuum would you expect to see from my motor at idle? 45 kPa when warm too little? It seems to go as low as 41 and I've seen as high as 50 kPa I've got 274 cams. I'm debating whether I should still check for vacuum leaks.

[digger]

Ignition to control idle is thing. If you imagine using a butterfly or other valve to control airflow there is a lag. Ignition is as instantaneous as it gets but the range of adjustment is limited using ignition so still need to have butterfly setup correct. Also don't want too much heat out exhaust with excessive retard

[betz]

Hahahah nah I'll do a proper video on Wednesday I think, showing off exhaust and WOT.

I am so stoked right now. The idle issue... it was the ignition. It's fixed, as far as I can tell. I flattened out all of my ignition timing near idle and retarded the heck out of it, advanced it below and retarded above so that it funnels it into a smooth idle, and it totally worked. I figured out because I noticed the ignition advance was fluctuating with the idle. I never knew the ignition could have such a pronounce effect, and shoot I had tried to keep the ignition table close to the base map. Eh well. That was fun.

Ugh god damn the car is so awesome right now. This was a great move. I wanna put this thing on a dyno again. Then... /thread. :o

[2mAn]

Lets see some pics and horizontal videos

[betz]

Alright, my car is running pretty well on the megasquirt now. GM IAT installed, no more AFM. I definitely still have some issues though.

Mainly, it seems sometimes I am getting an oscillating idle. My closed loop idle is not aggressive at all and the stepper is pretty much at a fixed position. But my AFR, MAP kPa and my RPMs are all oscillating together pretty bad. I know it's not the idle cus it will oscillate when I hold it at 2000 RPM even. I'm thinking I have a vacuum leak, or just my VE table is out of whack. I think the engine should be pulling more vacuum though- it's right around 45 kPa when I'm thinking it should be closer to 30.

It's odd though, because I first got it to idle well right after I trimmed up the VE's at idle. Later it seemed to get messed up after I had it autotuning at idle though I didn't even write the autotune to the ECU. I'm thinking all this stuff might be coincidental and I have a vacuum or exhaust leak. I might put the AFM back in and see if it idles on the stock ECU. EDIT: it idles steady with AFM and stock ECU.

Besides that issue though. Pulling like a freight train at WOT heheh

Here's a screencap from the log showing idle...

[betz]

I've confirmed the megasquirt I've received is working, got it connected to my computer and it has started my car.. albeit very very poorly.

I chalked it up to the mess of base tune vs firmware version, as when I loaded the base map from here: http://www.megasquirtpnp.com/mspnp2_maps.php
it gave me a ton of errors. Now I'm looking at either getting firmware version 3.2.1 or 3.3.1a so I can properly load this base tune, but looking at archived firmware versions, I did try 3.2.1 but the signatures or something doesn't match on tuner studio... http://www.msextra.com/downloads/arc...ive-firmwares/

Anyone know a good solid way to start this out? What firmware to load / what base map to load? I'm thinking at this point I'll go with the 3.3.3 firmware with the 3.3.1a tune, and then if it gives me any errors I will have to sort through them. Either that, or just load the latest firmware and do the same thing.

Also wondering if these base maps take the intake air temperature from the AFM and then use the built in MAP. Or if it's actually a necessity to install the GM IAT. I was planning on doing that, just not right away.

Update: Got the megasquirt on 3.3.3 firmware, loaded 3.3.1a tune, and a bunch of warnings popped up again, but it at least it loaded mostly. I then realized looking at the dashboard of tunerstudio... my MAP was reading 152 kPa when reading atmostpheric pressure. Atmospheric should be 101 kPa of course. Checked my MAP calibration.. saw there was a drop down menu for the sensor type. Popped open the whodwho and it's using a MPX4250 MAP, which was not the sensor that was selected previously. Changed that bad boy up and now my E30 runs pretty good on the megasquirt! Biggest issue is the tach output seems to be scaled incorrectly. But it idled and revved well.

I also contacted whodwho to see if I could get a hold of his base map. It's a shot in the dark, but if I could get a hold of that I'd be golden, seeing as it's also on version 3.3.3 I could load it very easily.
But where it sits, I could start tuning it now even, so I'm pretty relieved it seems everything is working out with this megasquirt. Next step... set my wideband to send the regular wideband signal, and for megasquirt to receive them, so I can start logging AFRs. Then start tuning!

[digger]

stock igntion, and batch injection is absolutely fine for the vast majority. It's a great place to start, nice and simple.

[AWDBOB]

Yep, exactly what I was asking! Awesome, I'll be following along. I'm going to do stock ignition for now as well with my motor, hoping it holds up with some colder plugs.

[betz]

The stock m20 ECU is actually better then people give credit. Sure, it's old tech, but in reality the m20 (and m30) are stupid simple engines. They only need to trigger the coil ground to fire the plugs and a batch fire injectors (just a pwm duty cycle) on the mechanics side, and be able to decipher oscillations from the CPS.

It's the aging flapper door type AFM that is causing issues 30-40yr later that people hate, buy in reality I was adjusting track wipers in them 12yr ago, and they wake right up.

I agree completely however this is also what has held me back from going to a full standalone for so long. I tried getting tunes, I got a wideband, I tried installing Sssquid's Alpha MAF conversion, tried many different AFMs, tweaking AFMs. It just seems the cold hard truth is my engine is too far from stock to ever be completely perfect on the stock ECU. There is also an approximately 0 chance someone in California can dyno tune with my stock ECU and burn me a perfect custom chip.

It's not the modern electronics I'm after, it's the fact I can tune or get this tuned to reach absolute perfection. And I feel I will learn a lot along the way as well.

AWDBOB I have no plans on doing coil on plug or wasted spark at the moment, if that's what you're asking. But for the future, who knows :)

[AWDBOB]

Glad to hear you got a MS setup. Are you staying stock ignition?

[ForcedFirebird]

The stock m20 ECU is actually better then people give credit. Sure, it's old tech, but in reality the m20 (and m30) are stupid simple engines. They only need to trigger the coil ground to fire the plugs and a batch fire injectors (just a pwm duty cycle) on the mechanics side, and be able to decipher oscillations from the CPS.

It's the aging flapper door type AFM that is causing issues 30-40yr later that people hate, buy in reality I was adjusting track wipers in them 12yr ago, and they wake right up.

[2mAn]

Im basically collecting parts at this point, and normally I wouldnt be hunting down the M30, but after reading this thread and seeing the smoking deal one was offered to me for, Im going to buy it.