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02loftsmoor |
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#1
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Senior Member ![]() ![]() ![]() Group: Members Posts: 577 Joined: 26-June 11 From: Ft. Worth TX Member No.: 13,243 Region Association: Southwest Region ![]() ![]() |
I'm check on going with distributor-less ignition system, some pointers please
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jarred |
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#2
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Newbie ![]() Group: Members Posts: 20 Joined: 13-March 09 From: seattle Member No.: 10,159 Region Association: Pacific Northwest ![]() |
Interesting. Not sure if you looked at my advert, you could use the VW 2.0 coil pack VAG part 032905106B/032905106E and skip the igbt's or mosfets altogether. It's about $30 on ebay. Just two logic outputs for wasted spark, similar to MSD (?).
I think the megasquirt code used to use just one trigger per engine revolution to calculate engine speed and advance (ignore the others), what I think you propose, it now uses time between triggers (interrupts) to keep a running measurement of rpm. I don't think engines change speed fast enough under load to really matter in one engine cycle. But you do need some kind of sync to determine whether to fire coil bank #1 or #2 which is what the skip tooth is all about. Just an idea, if it used two opposed hall sensors and 1 trigger tooth like D-jet does for switching injectors (was it half-multiport?), you'd have two interrupts: one for each coil pack and no need to create or decipher a sync signal. But I do think that an in-cap system on our air-cooled vehicles could have heat issues. The standard ATmega328p processor is only specified to 185 degrees F, and I kinda doubt it's going to be too happy at 184, or even 120, particularly if it's having to think very hard. That said, I haven't measured the temps in a cap. The ats617 sensor, an automotive part, was designed to operate up to 300 degrees F. |
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