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'''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: http://quasar.dynaweb.hu/~lezsi/bmw/attila/attila-injsettings.gif I guess a PowerFlyback couldn't be a bad choice here. If you're interested [http://quasar.dynaweb.hu/~lezsi/bmw/attila/datalog200512302240run.xls here's] a datalog with starting, badly oscillating idle, and cruising home with unmapped car, etc. For analysis I suggest my actual favorite: [http://www.ideasandsolutions.biz/MegaLogViewer/ 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? ** If above equation is true, using divider wouldn't twice inj-pw but cut into half! Please correct me. *** Divider means you get squirt every Nth trigger, Mostly suitable if you have injectors in banks. Doesnt affect pulsewidth at all. //Emil *** OK, I shouldnt say anything that I don't really know. I remember doubling pw from megasquirt, used with coil triggering. -OK, i feel totally lost. What happens if I change my divider to 2? * 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) * To keep same current, example if pwm@14v=30% pwm@6v=70%, so is injpwm6=40% correct? Or what is this multfact(VBatt)?
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