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Emissions w/ m52 on megasquirt

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    Originally posted by static View Post
    couple of corrections: MS2 can do variety of different injection patterns. One i experimented with and found best for is 6 alternating squirts per cycle (one can do up to 8 on a V8). With this setting, each injector gets 3 squirts per cycle, one of which will most likely be made on the open valve with 2 others on the closed one. The response with 6 alternating squirts per cycle should theoretically be very close to sequential (which i've proven on my car), but the atomization (as you mentioned) and especially useful range of injector ratings would be perhaps not as good as sequential - question is by how much?
    Even though not perfectly timed, the amount of fuel sprayed in semi-sequential mode still makes its way into the chamber (maybe not as well atomized) and it's not like the squirts are randomly timed or in random order, so i don't think that some cylinders get more fuel than others.
    I said "the best MS can do" meaning the others were even worse. injection with a valve open is a bad thing. bad for performance, economy, and power. Guaranteeing that it'll spray with an open valve isn't good. When the valve is open, not only is the fuel vaporization not as good and the chance for droplets higher, you can't guarantee which way the air is moving. If it sprays and there's a pressure wave coming out of the cylinder, no fuel goes in. You want a *packet* of vaporized fuel to be the first thing sucked in. You also definately want the injection event "done" before the air is going the wrong way or the valve is closed.

    6 alternating squirts is about as far from sequential as you can get. one squirt per revolution is substantially "closer", but obviously still not quite there.

    Originally posted by static View Post
    btw, is there a cheap emulator available supported by tuner-pro that would have the trace capability? (i.e tuner pro would be able to highlight the cells that ECU is reading from currently, while the emulator is hooked in)
    currently tunerpro does not support trace via the emulator. it should at some point in the future though. the ostrich 2.0 ( supports tracing now.