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Re: PCB for BMW m52 engine

Posted: Thu Nov 03, 2022 8:26 am
by pazi88
8m3dy wrote: Wed Nov 02, 2022 8:14 pm
I think I might have an older version BOM . Will check for the latest release. I managed to find an alternative for the zener diodes (original part 1N5919BG Zener : alternative 1n5339B ) it's way to big though so I kind of surface mounted them.
I started the car an idled it for about 20 seconds without the diodes (D6 D7 D8 & D13) as I'm not certain on their part numbers.
Thanks or the fast response Pazi88.
Well I just added those yesterday :D All older revisions are without those diodes, so those aren't mandatory. Those are flyback diodes and those offer more granular control for the PWM outputs when installed.

Re: PCB for BMW m52 engine

Posted: Thu Nov 03, 2022 12:43 pm
by 8m3dy
pazi88 wrote: Thu Nov 03, 2022 8:26 am
Well I just added those yesterday :D All older revisions are without those diodes, so those aren't mandatory. Those are flyback diodes and those offer more granular control for the PWM outputs when installed.
Again big thanks :D I appreciate it. I'm quite eager so I've got 1n4007 to try out. Will post back my findings.

Re: PCB for BMW m52 engine

Posted: Sat Nov 12, 2022 7:10 am
by 8m3dy
Seems I might of blown something. Car isn't starting. Tried it again after removing the extra diodes but still nothing. It's misfiring when cranking. Tried uploading 202202 base map again with all the other startup settings as advised .
Is there a way of testing the board or a method of fault finding
It's like it wants to start but eventually hooks

Re: PCB for BMW m52 engine

Posted: Wed Nov 16, 2022 8:45 pm
by Dagaz_Psi
Hello just put together a 3.0b board, and loaded 6inj and 3ign firmware to a mega2560. But it wont fire on cylinder 1-4-6. Is it not possible to run this pcbs with a mega or have I made a misstake some where?

Re: PCB for BMW m52 engine

Posted: Sun Nov 27, 2022 5:11 pm
by M5222
Hi Pazi,

I just followed your operating instructions for m52 in my m52b28 but I have some kind of problem with the injector flow.
In your guide, the b28 pink injectors flows 215cc/min (at 3.0).
And as i can find in other injector data sheets bosch pink injectors flow 250cc/min at 3,5.

So in the speeduino setting:

If I use 215cc/min, as you state on the guide, the engine bounce each 3 seconds, closing to shut off.

If I use 250cc/min the car runs perfectly fine.

I suppose we need to use 250cc/min but you don’t say that in the operating instructions, you only talk about 215.

In fact, about the injector voltage correction, your YouTube videos shows the same values as my stock speeduino setting, voltage 8 to 220% but your operating guide shows different values, Voltage 6 to 255%.

Knowing that the video have 3 years and the guide have 2 years, we need to use the guide obviously. I’m wrong ?

Re: PCB for BMW m52 engine

Posted: Mon Nov 28, 2022 9:06 am
by pazi88
You need to look your AFR where it's running. There is some conflicting info about those stock injectors and that 215cc is on the ball park. If you increase injector size in TS, it will reduce IPW and engine will run leaner. And that's why the RPMs don't raise anymore. You can just lower your VE on idle are to gain some. But look the AFR to which direction you need to go. The RPMs go up and down, because it's hitting DFCO threshold and activating it.

The dead times are correct from 8v up. The 6v value is actually too low even with 255. I have once again adjusted those so that 7volts is the lowest and is now at correct value.

Re: PCB for BMW m52 engine

Posted: Mon Nov 28, 2022 9:03 pm
by M5222
pazi88 wrote:You need to look your AFR where it's running. There is some conflicting info about those stock injectors and that 215cc is on the ball park. If you increase injector size in TS, it will reduce IPW and engine will run leaner. And that's why the RPMs don't raise anymore. You can just lower your VE on idle are to gain some. But look the AFR to which direction you need to go. The RPMs go up and down, because it's hitting DFCO threshold and activating it.

The dead times are correct from 8v up. The 6v value is actually too low even with 255. I have once again adjusted those so that 7volts is the lowest and is now at correct value.
So if bosch state 215 for 3.0 and my car with 3.5 and 215 setting is hitting DFCO, definitely I need a increased setting at least.

About the voltage value, in the recently “hours “ version I can see that you have new operating instructions with 0,7 dead time for pink b28 and 6v 255
8v 201
10v 133
12v 91
14v 60
16v 37

Or 7v for 255 as you say in the previous comment ?

So I suppose they the up to date values .

Edit : the English operating instructions have the 7 voltage sheet but the Poland operating instructions have yet the 6 voltage sheet, that explains my confusion.

Thanks again for all what you are doing

Re: PCB for BMW m52 engine

Posted: Mon Nov 28, 2022 11:35 pm
by PSIG
You can extend the data curve to find the correct %. Your 215 at 3bar would flow roughly 232 at 3.5bar. However, I would turn off DFCO and tune what you have before turning it back on. Automated and advanced functions always mess with the tune if enabled too early in the process, making the tune unstable. Build the tune foundation first.

Re: PCB for BMW m52 engine

Posted: Tue Nov 29, 2022 12:35 am
by M5222
PSIG wrote:You can extend the data curve to find the correct %. Your 215 at 3bar would flow roughly 232 at 3.5bar. However, I would turn off DFCO and tune what you have before turning it back on. Automated and advanced functions always mess with the tune if enabled too early in the process, making the tune unstable. Build the tune foundation first.
Really thankfull for your advice!

But about the injector flow, I think bosch stated 21,5 lb/hr for 3bar and 23,8 lb/hr for 3,5 bar and maybe I’m wrong but 23,8kb/hr is 250cc/min.

Re: PCB for BMW m52 engine

Posted: Tue Nov 29, 2022 2:27 pm
by PSIG
My numbers were from flow calculations at different pressures, not cc > lb conversion. I think you are approaching the issue by trying to make a generic tune "fit" your engine, rather than adjusting the tune to match your engine. To some degree the injector flow is not critical at this point, and you need to tune with the data you have. As you tune, you will find the "correct" values for injector flow, latency, etc, for your engine.

Make a copy of your current tune, turn off auto-functions, and name it "Warm_Idle". Begin experimenting with tuning your warm idle to minimum MAP, using the data from Speeduino. When it's good, rename it "Daily" or "Best" as your best driving tune so far. Rename a copy of that for the next tuning task (e.g., "Warm_Restart") and repeat. If you get frustrated or lost, it is easy to roll-back; just load the last-best tune and try again. It is a tunable ECM, meaning you need to tune it to your specific engine, fuel, use, etc. Get started! 8-)