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IMPORTANT: enter the case-INsensitive alphabetic (no numbers) code AND WRITE SOME SHORT summary of changes (below) if you are saving changes. (not required for previewing changes). Wiki-spamming is not tolerated, will be removed, so it does NOT even show up in history. Spammers go away now. Visit Preferences to set your user name Summary of change: '''Injector measurement''' I was interested in injector opening/closing time, flow regarding to flyback setups. '''NEWS 2007.02.05''' Previous measurements were obviously inaccurate, so I started over with better equipment: http://quasar.dynaweb.hu/~lezsi/vems/accel-flowtest1.gif http://quasar.dynaweb.hu/~lezsi/vems/holley-flowtest1.gif It's now the "what we've expected" chart, linear, with some degradation in flow at low pw values. I started with the smallest possible pulse (which actually made the injector open). Holley is low imp, so it's faster to open/close. It needed almost 50% pwm duty at 11.5V battery, otherwise it couldn't stay open. Still seeking the answer to the question: Why we couldn't get stable idle with lower than 3ms with the Accel inj above? (And why it's using 90% duty to feed ~300 horses on a 6cyl/6inj engine?) ** Reasons might be many. Maybe an AFR is a too much on a rich side and spark advance (seems to be 21 deg at max) few degrees too little. At least if datalog link below reflect your settings. http://www.vems.hu/wiki/index.php?page=MembersPage%2FGergelyLezsak%2FBigSixTurbo%2FInjectorsTwo ** Similar engine, with 7.5:1 geometric compression ratio, ported head, std camshaft and 0.65-0.69 kg/cm2 boost delivered 203 Kw/400 Nm. Injectors used are Bosch EV6 four hole design, 261 g/min (about 350 cc/min). http://www.vems.hu/wiki/index.php?page=MembersPage%2FBengtR ** max. ignition advance is around 28-29 deg at 0.7 kg/cm2. Min lambda 0,84-0,85 and max. injector duty around 58 %. ---- 2007.01.26 I did some measurements with setting cranking RPM range high. Basically it worked fine, but two problems arised: 1. Pulsewidth simply disappears (goes to zero) after some amount of time. Time's between ~40-120 seconds of "cranking". Sometimes it doesn't need to have RPM signal at all just change settings in megatune, and pw on LCD/megatune/in_reality changes to 0000. Switching off/on resolves the problem for the next ~100 seconds. 2. Above 20ms of cranking pw, scale changes to 0.5 msec (so 20.0 + 55*0.5 = 47.5 msec can be specified at max: rarely needed, but it is by design). Above 25.5 msec, megatune displays pw - 25.6 msec. About the results: http://quasar.dynaweb.hu/~lezsi/vems/flowmeasure1.gif I'm not sure whether this is normal or not. I expected a linear growth of flow with pulsewidth (at least in the higher range). ** Results are certainly somewhat wrong. Did you measure actual pulse width. Measuring opening time with oscilloscope or graphical multimeter etc. would clarify measurements. //BengtR All of the above pulsewidth values includes all timing (I have set all open times to 0) ---- 2007.01.22 I've put together a flowbench-setup http://quasar.dynaweb.hu/~lezsi/vems/flowpad-small.jpg First tests showed that injector opening time increased slightly according to the fuel pressure introduced (3 bars). No flow measurement data yet. Question: How can I force GenBoard to a specific pulsewidth? -Tried "mxofemxofemxp05mxp05" and similar, but no effect at all. I would use a soundcard ElectronicDesign/TriggerSignalGenerator with 60-2 or similar pattern, and use "cranking RPM" (both low-temp and high-temp values set to same pulsewidth). you can bump up cranking_thresh, but best to apply 290 RPM or similar. Take care (and have multiple fire extinguishers at hand). -It good-and-working idea, thanks. ** You might want to measure (if measuring 'acutal' flow rate) at around 6000 1/min (ie. 100 Hz) or similar (depending your engine maximum revolutions etc.) and around 80-85 % opening time (ie. 8,0-8,5 ms at 100 Hz). //BengtR ** Good idea, I'll check it later, first I'm interested in the idle-area. ---- All of the below measurements made on a 12 Ohm Hi-Z injector dry -without fuel pressure-, and PowerFlyback installed inside the ECU. No PWM-ing was enabled, pulse width is ~14ms. Voltage was 12.1-12.2V, voltage/current measurements were made after a 0.3Ohms resistance, so test setup is like: +12.2V____[0.3Ohms]____*Measurement*____[injector]____INJ-OUT The results: http://quasar.dynaweb.hu/~lezsi/vems/3flyback.gif Red channel means measurement voltage (or current). Blue channel means mechanical movement/noise. *1. graph is one open-hold-close pulse with '''no external flyback'''. Closing time is '''1.7ms''' *2. graph is similar open-hold-close pulse with '''18V Zener flyback'''. Closing time is '''~0.95ms''' *3. graph is similar open-hold-close pulse with '''30V transient diode flyback'''. Closing time is '''0.9ms''' -all of them includes internal PowerFlyback- It's visible on the red channel that after opening (about 1ms later) current has a pulsation which shows the movement of injector iron core. At the same time mechanical noise started (blue channel). At closing phase there's not visible current-pulse in red channel but a spike goes well over starting (+12V) voltage which is the inductive "kick-back" or flyback current. Blue channel's mechanical noise shows here the exact position of mechanical injector closing. As my movement/noise detection (knock sensor) was nearly installed on the injector it's coil slightly picked up injector current, so on the blue channel it's also visible when injector current switched on/off (a single spike before noise). http://quasar.dynaweb.hu/~lezsi/vems/inj_knock3.jpg Optional: Add document to category: Wiki formatting: * is Bullet list ** Bullet list subentry ... '''Bold''', ---- is horizontal ruler, <code> preformatted text... </code> See wiki editing HELP for tables and other formatting tips and tricks.