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VEMS looks to be just the thing I was looking for to go beyond carburettors. == My project == * Guzzi V75/4 motorcycle * 90 degrees 2 cylinder V-twin, firing interval 270/450 degrees ** that is "gaps of" 3 and 5 (*90 degrees), respectively. So an 8 cylinder setup with only ignchannel2 and ignchannel3 used out of the 8 (the rest mapped to unused ignchannel7): ** h[2]=07 07 07 07 03 07 07 02 * 750 cc, Normally aspirated. carburettors: 2x Dell'Orto 30 mm * 65 Hp approx, 7000 rpm max. * I already have a NB O2 sensor in one of the two exhausts (helped in jetting the carburettors. ) I will use the bike for street use only. Basically, I want to learn hands-on about EFI. I am not looking for a performance increase. Lower fuel consumption might be nice, though. Me and my Guzzi on a cold morning last winter: http://www.vems.hu/files/ArnoudvanderWel/guzzi.jpg Bought lots of second hand EFI bits from a Moto Guzzi Quota to make a start.. :) http://www.vems.hu/files/ArnoudvanderWel/efi_bits.jpg * Two intake manifolds with Weber-Marelli IW 042 injectors (16.2 Ohm, 190 cc/min @ 3 bar) * Throttle body with two 42 mm throttles and TPS * Fuel pump (Weber PI021), filter, regulator (2.5 Bar) * Various sensors and the original Marelli P7 ECU which I will not be using. == Plan == * Modify intake manifold to fit engine; fit throttle body, air filter, fit other EFI bits. * Generate more timing info; either by multi-toothed wheel for the camshaft VRS or add VRS on the crankshaft. * Buy VEMS! == Eventually == * Have the VEMS do ignition as well as injection. Load-dependent ignition advance will be nice, I only have an RPM-based advance now. * One, maybe two WB02 sensors? ---- '''Trigger''' 1. At present I only have this (VRS) trigger for the ignition on the camshaft. There is no cranksensor. http://www.vems.hu/files/ArnoudvanderWel/trigger.jpg I want to make a new rotor for this with more pulses. At present I am thinking of 12-1 teeth. Since I have two pickup coils (135 degrees apart), I can then do 'static' position detection: Normal operation means the two pickups generate alternate pulses and the missing tooth gives two consecutive pulses from the same sensor. * Is 12-1 on the camshaft a sensible idea or are there good reasons to make something else? ** '''you want 16-1''' 12-1 is not good because there is no good trigger-tooth selection that way (for both cyls). Check the h[2] thoughts above ---- '''MAP sensor''' I have is rated at 100 kpa. 100 kPa should work well in an NA engine. No need for the 250 kpa sensor (but that would work too). ---- '''Fuelpump PWM''' 3. I am rather short on electrical power. I have a generator that puts out 280W at most, and after 80W for lights and 25W for heated handgrips, that doesn't leave a lot for EFI. I was thinking of doing PWM for the pump to save power. I can see two possibilities. a) Measure fuel pressure, no return line, and PWM the pump to keep the pressure constant. b) Keep the pressure regulator and the return line, but PWM the pump (feed-forward, based on injection pulsewidth, RPM and battery voltage, all of which the ECU knows), to keep the return-flow as low as possible to save power. '''PWM-ing the fuelpump seems more risk than benefit'''. Also, you want to have available electric power even at maximum engine power. 175W / 12V = 14.6A * 2A for injectors * 1A for ignition * 0.3A for ECU * leaves 11.3A for fuelpump. Isn't that enough for an NA bike pump ?
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