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

[betz]

I have not touched my M30 AFM. It's one that was refreshed by Bavrest so I didn't feel comfortable opening it up and messing with the tension spring. At first I had Sssquid's tune on it which seemingly compensated for the AFM, but my motor ran better with the stocky stock M20B25 ECU. The mixture at WOT was much better, and after the ECU did it's learning it hovered around 14.7 in most situations, except for cold start. I am running S52 pink top injectors, I do also have an adjustable fuel pressure regulator that's dialed in to stock fuel pressure.

I agree that, on a stock M20, 19lb injectors and an M30 AFM is a bad idea. If you have a stock M20 just enjoy the stockness of it being turn key and just working like a factory motor. The potential for like 5 hp is just not worth it.
I feel like, just a weird combination of what my motor is, higher comp cammed stroker motor, with the M30 AFM, pink top injectors, long tube headers with a wideband O2 sensor, somehow worked out to work with stock lol. My AFRs don't lie, it is actually running good. I only did it because my car was having weird problems, I stuck the stock computer in and holy crap why is it running better haha.

But now, I can get it tuned proper, and yes ForcedFirebird if I disconnect the ECU, my motor does strange things. I usually get one big miss, the O2 sensor seems to restart(?), then my car is mostly fine from there. Yeah... I'm thinking moving to a megasquirt is a really good move.

[ForcedFirebird]

Best way to use the m30 AFM is to just load the AFM transfer function maps from an m30 ECU onto the m20. I do it all the time on turbo m20's. Just plugging the AFM in and adding 19lb injectors to compensate the AFM tables is a hack at best. The ECU still needs to learn, the Motronic resets every time the battery is disconnected, and runs like crap until it relearns.

[2mAn]

How did you have your M30 AFM adjusted? I’ll be picking one up and plan to run it with the Mustang injectors and stock ECU. That’s how you felt it best, right?

[betz]

It's long overdue, I finally got my hands on a Megasquirt. It's a used whodwho plug and play. Looks like I'll be ditching the AFM the easy way, hehe.

In other news, the car has been smogged for it's second time. It just squeaked by, my AFR at part throttle is not as good as WOT, the O2 has to trim it quite a bit especially when cold. Cool though that I found a friend of a friend who shrugged off my shiny headers.

I figured, with the megasquirt I can finally get my car actually perfect and finally give my O2 sensor a break haha. And eventually I'll take it to get it dyno tuned when an opportunity arises & get those extra ponies.

[betz]

Any plan for a exhaust video? I'd love to hear what this combo sounds like.

I will try and accommodate. My car is relatively quiet. Sounds a bit hot rod at idle, but you wouldn't notice anything is different unless you're an E30 guy ;)

I love the sounds at WOT, definitely makes it feel like an event, that's when you really can tell something has been done to it hehe

[betz]

What chip was in the old system?

Sssquid custom tune. Like, the third or fourth revision of it lol

[2mAn]

On a whim I tried plugging in a totally stock ECU.
.... My old ECU must have been wonky at least, but I'm more surprised how seemingly perfect the stock chip is.

What chip was in the old system?

[Motheye99]

Any plan for a exhaust video? I'd love to hear what this combo sounds like.

[betz]

So I wanted to share something quite interesting...

I was having a few issues with my car, first being that I had these bad hesitations that seemed to happen more and more often. I checked almost every piece of my ignition system and kept thinking I fixed it only for it to come back again. Meanwhile, I had gotten a gauge for my WB O2 sensor and have been monitoring it to see how good my tune is under various conditions. I noticed that WOT was super super rich at 9.1 AFR which was also causing a more subtle hesitation when at WOT. The other hesitation seemed ignition related as it was a more sudden lurch than when running rich. Also at part throttle my AFR oscillated around 14.7 even though I would still get hesitations.

On a whim I tried plugging in a totally stock ECU.

Not only did it fix my hesitations (so far, at least, 3 days strong) but my AFR at WOT now hovers around 11.8-12, which is nearly spot on, maybe a few tenths too rich.

So, I guess somehow.. S52 injections= richer, M30 AFM = leaner, displacement/cam/comp = leaner... So somehow the stock tune works well? I have no idea to be honest. But my car has just been an absolute joy with the stock tune, it's running more solid than ever! Hopefully it stays that way :). My old ECU must have been wonky at least, but I'm more surprised how seemingly perfect the stock chip is.

[betz]

Thanks! For the most part, yeah. I plan on finishing the MAF conversion, doing an oil cooler, mtech1 spoiler, and euro valence + fogs.
I'm taking it at my own pace because the car is awesome as is, pretty much everything I could've hoped for and even then some. It's not perfect, but its close, and will only get closer as time goes on.

[2mAn]

Car looks good!... is it "done" basically?

[betz]

My E30 looking especially cute playing in the fall leaves. Its been one year since I started the motor and it's still running strong!

[AWDBOB]

I haven't really tried anything on it since last update honestly. My starter is going out for some reason now, so I pulled it out yesterday and will be putting a new Bosch reman in it later today.

I figured after that I might try fiddling with the MAF a bit more.

How about you? You had a MCK too right?

I got an MCK as well- I haven't made any progress, though. Hopefully once things settle down a bit I'll get it installed.

[betz]

Did you ever get the MAF working?

Not exactly. I think I did update a while back where I got it to power on through a voltage supply, so my next idea was that the pin that was loose (happened to be the voltage pin) was probably getting pushed in so that it did not contact. I was going to fix that in place somehow, then play dumb and follow the instructions to see if it works out.

I also bought a new enclosure for it since the 3D printed one disintegrated on me.

I haven't really tried anything on it since last update honestly. My starter is going out for some reason now, so I pulled it out yesterday and will be putting a new Bosch reman in it later today.

I figured after that I might try fiddling with the MAF a bit more.

How about you? You had a MCK too right?

[AWDBOB]

Did you ever get the MAF working?