M50 Turbo Winter Project

[SirMaxximus]

HUGE UPDATE:

All the issue's I was having with the tune are completely worked out! Got the car up and driving on the road today, drove it for about two hours letting autotune trim a ton of fat! Boost comes on quick and pulls really solid! Completely stoked! engine sounds good and healthy, exhaust sounds fantastic! Today was a big day!

I have a 7lb spring in my wastegate and the manual boost controller set all the way down.. Wastegate seems to work great, goes to about 6psi and holds strong on every pull, no spike! no creep! holds good.

I had to really bump up my AE in order to get it going and stay alive... pazi88 you were 100% right, my VE table was just that far off and causing all of my issues.. It was a scary process for the first 15 mins with some scary lean spikes at first, but it got much better very fast with autotune on.. basically getting it away from the initial stop signs and to some long stable roads to do some controlled pulls with light throttle changes was the key.

I idled it so much in the garage the last two weeks and drove so much today I had to stop and get gas near the end of the drive!



Big huge thanks to everyone thats commented and given advice, looked at my tune and datalogs! Thank you, still plenty left to do with this project but today was a big accomplishment and I finally got to just enjoy driving it!

[SirMaxximus]

Don't use ego correction while tuning ve map. It will make it almost impossible to fine tune values. Alao disable AE also. Use only very slow thorttle movements when tuning VE to make sure that the required AE doesn't cause lean spikes. Only when you have whole VE table tuned, turn on the EA and adjust that so that the engine doesn't stumble when thorttle is pressed more quicly. When that is done, you can enable ego correction. But when VE table is correctly tuned, there is not much need for that.

EDIT that AFR dip is just your AE settings. The TPS dot threshold is too high. But as I said. Don't worry about those yet. Tune the VE table so that AFR is good with stable TPS and then start tuning the AE. I would also suggest changing the lowest RPM row to about 5-600 RPM. To tune that, put the car on first gear. Start driving and keep the RPM and below idle level using brake and using throttle you can reach all the map cells there. Autotune is your friend here. This works for higher RPM also.

Thats the problem tho mate. With the AE off its totally undrivable, it'l stall trying to engage the clutch.. Or it will get going then surge and stall.. I tried it today. After some serious struggle I finally got moving, got into second gear and the AFR was good at steady throttle very briefly (around 13)... then randomly climbed to 22 and leaned out and fell on its face while driving.... unfortunately I also live in a neighborhood within the city with lots of stop signs so I'll have to find a better spot with a long un populated road, problem will be getting the car there without blowing it up! lol that might be all part of the fun, but it would be nice to boost before she pops! haha

I'll keep tryin this none the less, the lightweight flywheel and 6-puck clutch are probably not making it easier to ease the throttle either, lol. your video's have been super helpful btw I've watched a ton of them. I know the VE table's way off and that this is the place to start, I'm just having trouble actually getting it to the non-idle cells to see what it needs. I did change the VE scale a bit today as well to include 600rpm range

[pazi88]

Don't use ego correction while tuning ve map. It will make it almost impossible to fine tune values. Alao disable AE also. Use only very slow thorttle movements when tuning VE to make sure that the required AE doesn't cause lean spikes. Only when you have whole VE table tuned, turn on the EA and adjust that so that the engine doesn't stumble when thorttle is pressed more quicly. When that is done, you can enable ego correction. But when VE table is correctly tuned, there is not much need for that.

EDIT that AFR dip is just your AE settings. The TPS dot threshold is too high. But as I said. Don't worry about those yet. Tune the VE table so that AFR is good with stable TPS and then start tuning the AE. I would also suggest changing the lowest RPM row to about 5-600 RPM. To tune that, put the car on first gear. Start driving and keep the RPM and below idle level using brake and using throttle you can reach all the map cells there. Autotune is your friend here. This works for higher RPM also.

[SirMaxximus]

Still having the same problem... I took a shorter datalog to share. Engines already fully warmed up, datalog starts at idle. I mostly just tried to give it a few light throttle changes from idle and a major lean spike that happens... its bad enough that the engine will stumble, surge and stall upon most throttle changes. it stalls out several times near the end of the log actually... I've tried richening up the surrounding cells alot.. probably too much as the cells just above idle has a much larger VE value now and is not very smooth transition, but nothing seems to stop this major lean spike... If anyone has time and is willing to look them over I would greatly appreciate any input.

Links to the datalog + MS configuration from my google drive account:

https://drive.google.com/file/d/1O6hQWpG1pp_NS09TJJk_weKtFOz4yhur/view?usp=sharing

https://drive.google.com/file/d/1oP2Wt-hCas7g0WKZVTsDkItr0UOOw7rg/view?usp=sharing

Notes: EGO control is 5% here, AE is time-based, over-run is off. I've tried all 3 of these at different settings or off entirely. This seems to have the least likelihood of stalling out for me at the moment.

Things I've tried recently:
Removing + cleaning injectors
Checking vacuum leaks
All sorts of AE settings + changes
All sorts of VE settings + changes

Things on my list to try next:
Check fuel pressure with gauge

[SirMaxximus]

Yeah that's pretty normal. There is big changes in VE happening around the idle area. As I said, it takes long time to tune the VE table. You may need to adjust the axes also to suit your needs.

hmmm so it sounds like this is still a tuning issue then... I was afraid to go much further. I thought something else had to be wrong to have such bad lean spiking....


I went back at it today however and got it worlds better! it still spikes upon light throttle but was able to get pretty much the entire 30-35kpa range in a good 13-14.5 range. also fixed some spots above and below idle... upped my idle speed a bit, almost to 1000rpm (but i can lower this once i get the tune right) but now I can actually drop the throttle without it stalling.... I decided the next step is to put some light load on it to start slowly tuning the cells above 35kpa... I lowered the car and got about as far as the driveway. see photo



but then it stalled on me and wouldnt start up again... I've been having an intermittent issue with the starter as well... It's a wiring issue to the solenoid, the S terminal is only seeing 7volts when cranking... Battery terminal is seeing 12+ tho, so it will start right up 10 times in a row then it randomly wont start for like an hour cause it feels like being picky..... I'm gonna pull the manifold back off this weekend and figure out where the resistance is... it would really suck to get stranded while trying to tune just because the starter is acting up.... anyways, it seemed the car was telling me it wasn't ready for load yet! lol

[pazi88]

Yeah that's pretty normal. There is big changes in VE happening around the idle area. As I said, it takes long time to tune the VE table. You may need to adjust the axes also to suit your needs.

[SirMaxximus]

Tried again today. Same issues, but was able to get datalogger to work.

Okay.. so here for example.. Throttle position goes from 0% to 2.3%... I've barely moved one cell.. MAP barely moved from 30 to 34kpa. Yet my AFR spiked lean from 13.8 to 17.5....... this minor of a change shouldnt justify such a major confusion within the system....


Here's a different VE map... been trying to adjust things on it but havn't made it far off of idle... so the rest is pretty untested... I tried to curve it much richer right off the bat but AFR still spikes upon small changes... once it settles I can tune a particular cell

[SirMaxximus]

But it's quite tedious and there are other easier ways to do that. Like I have shown in my video: https://youtu.be/UsfIOF-pGZs?t=1m37s

Mine isn't quite to this stage yet still.... definitely can't drive yet... I can't seem to get it off idle without falling lean then rich then stalling... even under light throttle changes..

I've tried lots of different things so far with not much luck, here's what I've changed so far:

*VE table - I'll post a new one up soon.
*Added wideband authority - tried up to 20%, after getting the VE table right I've heard its okay to leave this on at 5%-10%.
*updated injector deadtimes to .786ms (should be correct now)
*updated knock sensor details (does anyone have preferred settings for this or a way to test and see if its getting a signal without the obvious idea of purposely introducing knock!)
*disabled Idle VE

Here's what I know and what is consistent no matter what I change:
*car starts up and idles no problem, will idle all day around 13.8 once it warms up
*Idles just north or 20hg. no surging, idles fine. I tested for vacuum leaks. found nothing concerning, I could bring a smoke tester home from work if need be but I dont suspect vacuum leaks.
*once it warms up it will start then die immediately unless you ease the throttle. (I assume I just need to add more "afterstart enrichments"... not a big concern of mine until the rest is worked out)
*if I ease it (and I mean, really really ease it!... its a real touchy ease) to any rpm I can manually adjust my VE numbers and get the AFR where I want it... I'm almost always too rich and it needs to be leaned up a bit
*upon any rpm changes I get extreme lean spots... even when trying to ease!... if I go too fast, it bogs and stalls. even if I don't go too fast, it may bog and stall..
*same goes for letting off the throttle, it will lean + bog if you dont ease it down..... once I get on a specific rpm I seems to handle it just fine and timing seems fine, no hot spots on the turbo, no kickbacks or obvious knocking.


I've tried playing with the accel enrichments slightly but I have been told by numerous people that you should be able to tune the VE table with Accel enrichments off entirely... which is the stage I'm stuck on.... so I feel like something is wrong elsewhere and I'm not sure what.... Im wondering if my injectors arent producing adequately.... got the injectors secondhand from a bimmerforums member, they are genuine bosch and were known good and working good for him.

I also tried to datalog my entire session yesterday. but I didn't have checkbox "save this datalog as:" checked.... so stupid me, I guess it didn't save at all. seems odd, like why would someone start the datalogger if they didn't want to save the file! lol..... either way I'll actually datalog next time, hopefully that will help

any other ideas, I'm very open to them! haha




Heres the good news tho: I got my driveshaft and everything else worked out. car is officially ready to drive other than the tune issues

[jeenyus]

awesome. great project.

[SirMaxximus]

The VE generator makes map that allows you to somewhat run the engine :D Nothing more. There is lot of ways to tune the VE table. As you said, you can use throttle and drive the car to reach the cells and adjust them to desired AFR. But it's quite tedious and there are other easier ways to do that. Like I have shown in my video: https://youtu.be/UsfIOF-pGZs?t=1m37s

The tooth #1 is at that 324 degrees. But the exact value need for megasquirt depends bit on the used crank sensor etc.

Funny, I actually stumbled upon a few of your video's quite awhile ago when I was first starting this project. That's helpful!

I did use a timing light and verify my timing last night. Tried a few numbers in that area and found 324.5 to be dead on for me.

[pazi88]

Awesome, thats kind of what I thought might be the case with that "fuel pressure" setting. Sounds like I have the injectors entered correctly then as I calculated the difference for 3.5bar.

I just kinda assumed the "VE generator" would do a better job than that! lol But it sounds like most of my actual settings are okay and I just need to make some major adjustments to my VE table little by little. Is the correct way to do this by getting it to different RPM's with a steady foot and adjusting the VE cells while running based on what I'm seeing from my wideband?

The VE generator makes map that allows you to somewhat run the engine :D Nothing more. There is lot of ways to tune the VE table. As you said, you can use throttle and drive the car to reach the cells and adjust them to desired AFR. But it's quite tedious and there are other easier ways to do that. Like I have shown in my video: https://youtu.be/UsfIOF-pGZs?t=1m37s

The tooth #1 is at that 324 degrees. But the exact value need for megasquirt depends bit on the used crank sensor etc.

[SirMaxximus]

Ignition settings are fine. But you can use lamp to confirm that it's spot on. Just fix the ignition angle to 0, crank engine without injectors plugged in, and use lamp with stock DTC mark to confirm that it's ok. You need to hack temporary ignition wire for cyl1 coil to be able to plug in the timing lamp.

Ignition map seems fine also. You need some way to hear knock before you can tune that more.

And about the engine bogging. You first need to fully tune the VE map and it's quite time consuming. It can take weeks of tuning for newbie before it's even in ok condition. The engine should run fairly good, when the VE map is correctly tuned. Then you can start fine tuning the accel enrichment settings only after VE map is good.

EDIT that fuel pressure setting is only for PWM fuel pressure control. When you have it Vac referenced as you have now, that setting has no effect. You will need to take account of the fuel pressure difference (3 bar vs. 3.5 bar) in injector CC setting.

Awesome, thats kind of what I thought might be the case with that "fuel pressure" setting. Sounds like I have the injectors entered correctly then as I calculated the difference for 3.5bar.

I just kinda assumed the "VE generator" would do a better job than that! lol But it sounds like most of my actual settings are okay and I just need to make some major adjustments to my VE table little by little. Is the correct way to do this by getting it to different RPM's with a steady foot and adjusting the VE cells while running based on what I'm seeing from my wideband?

I'll grab a timing light today and make sure that #1 tooth is right first, I have an in-line coil tester which I should be able to use as a temporary spark wire for a timing light.... I just havn't had to use a timing light in a long time, and it kind of surprised me that the #1 tooth could have differences between engines.. but your right, that would at least confirm for me that I have that entered correctly

[pazi88]

Ignition settings are fine. But you can use lamp to confirm that it's spot on. Just fix the ignition angle to 0, crank engine without injectors plugged in, and use lamp with stock DTC mark to confirm that it's ok. You need to hack temporary ignition wire for cyl1 coil to be able to plug in the timing lamp.

Ignition map seems fine also. You need some way to hear knock before you can tune that more.

And about the engine bogging. You first need to fully tune the VE map and it's quite time consuming. It can take weeks of tuning for newbie before it's even in ok condition. The engine should run fairly good, when the VE map is correctly tuned. Then you can start fine tuning the accel enrichment settings only after VE map is good.

EDIT that fuel pressure setting is only for PWM fuel pressure control. When you have it Vac referenced as you have now, that setting has no effect. You will need to take account of the fuel pressure difference (3 bar vs. 3.5 bar) in injector CC setting.

[SirMaxximus]

SHE STARTS and runs! did the first startup last night! I think something is not correct in my settings tho, seems to go pretty rich at idle then falls on its face after you give it a little gas, goes very lean as soon as you give it gas. I'm going to post all my settings below and ask some questions. I based and started entirely off of a "stock m50 tune" that came with my msproPNP, I just changed things from there and tried to leave the sub 100kpa maps alone. I'll post up a startup video soon!




My brother takes selfies as I try to wrap my head around tuning!


I used the "required fuel" calculator and ended up with 5.9ms. Questions here: I have 440cc injectors (bosch 42lb green giants)... but that is at 3bar of pressure, I always understood bmw's to be at 50psi or 3.5bar. So I calculated and entered 472cc injectors... is this correct or does megasquirt already take this into the equation?



This morning I found a whole other section where it specifies... obviously here it states my pressure being 43.5psi... so one of these needs to change so that they agree with each other.



Final question regarding fuel.... I didn't change anything in the Accel/Enrichments section.... Should I? perhaps this is why it goes lean and falls on its face when I give it throttle. This is how the "stock M50 tune" had it set up... it looks like its entirely TPS based instead of MAP based.



Sensor settings:



Next lets talk about ignition settings:

#1 tooth was at 327 degree's from the "stock M50" tune... I saw others online stating 324 degrees or 324.5... in toothed wheel mode it should be pretty straight forward? i mean the wheel only goes on one way... Can you even realistically check this with a timing light on coil on plugs? I didn't notice any marks to look for timing wise but perhaps someone can point me in the correct direction here... I set it to 324.5, no backfires at idle, no kickbacks upon startup. seemed fine... again tho I didn't get the engine far off of idle before it leans out though.



Here's the ignition map. I just took the stock m50 set up and rescaled and adjusted the curve a bit.. I think I'll need more advance at WOT, it seems extremely conservative based on what I've seen from others... But obviously if #1 tooth is 327 in their stock tune then that would drastically effect the ignition map... which I changed to 324.5....



Fuel Map:



VE table:



Clearly something is wrong here... just not sure what...

Otherwise heres the good news: it actually idled pretty decent! All my inputs and sensors seem to be reading accurately on tunerstudio. My AFR gauge is perfectly in sync with tunerstudio's reading. Also, it freakin runs!

Bad news: My new fan not turning on! Jumped the switch and it fires right on, so I'm kind of deducting that I must have a faulty switch right off the bat...

[jeenyus]

really coming together! Keep up your motivation. I'm sure once it runs you'll be so on fire to finish and keep pushing through this great project.