This page is dedicated to Low-Z injector tuning, at BMW M30B34 turbo engine.
Injectors are the stock ones for this engine: Bosch part no. 0 280 150 200, maybe 270-300 cc/min @3/3.5bars (different sources say different values). R=~3 Ohms.
My previous calculation was for required fuel:
Req_fuel = 6.49 * (D / N / I) = 6.49 * (3450 / 6/ 300 cc/min) = 12.44 ms = 0x7C
Which seems to be on the high side. (So the injectors are not 'so' big for this displacement).
But engine was flooded with those values, finally I ended up with a Req_fuel of 5ms, and still I've got VE values of 20-30 (decimal) near idle. Idle is ~1ms pw.
I guess something is wrong with injector settings. I worked with the following settings:
I guess a PowerFlyback couldn't be a bad choice here.
If you're interested [here's] a datalog with starting, badly oscillating idle, and cruising home with unmapped car, etc.
For analysis I suggest my actual favorite: [MegaLogViewer] the first program which knows everything I wanted, not buggy (just a bit slow -java)
- Have you tried divider 2 (or is it 3 for 6cyl? I dont know), so no injection on every rotation -> twice longer pw.
- I'm not sure about inj calculations (and manual doesn't cover divider config), but let me guess: if (alternate+1)*divider should be equals to 6 in my case, then if I use divider=2, then I need to use alternate=2 which means to me that I have to form 3 injection banks?
- Powerflyback may help if pw is near 1mS, someone else may know it better.
If (injpwm14 + multfact(VBatt) * injpwm6 ) > 100% (at certain - low enough - VBatt) than it is railed at 100% (since that is the limit of the duty)