CAS question
09-24-04, 10:24 AM
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Right near Malloy
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Should... Carl and Sterling said they saw several at 7 stock with em on there... Made for an interesting quaad coil direct fire ignition system.
Goto the junk yard and try it out.
Goto the junk yard and try it out.
09-24-04, 10:34 AM
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What we didn't see at 7stock was what took the signals from the CAS and signaled the coils. You might want to pick up the ECU while you pick up the CAS. Then experiment and let everyone know what you found.
09-24-04, 11:21 AM
#5
The code blue car has it. That setup doesn't give the benefits of a dual leading direct fire ignition system because it sparks the leading plugs at different times (like a stock FB cap 'n rotor setup). I would also doubt that there is an LT split due to the extra complexity it adds.
I think it's just a way for RX-7 owners to feel good about giving each plug its own coil, even though leading plugs do 99% of the work, making trailing unnecessary to upgrade.
Of course this is mainly speculation. Who knows; that system *might* at least offer an LT split. I seriously doubt the brainchild behind it allowed for the dual leading sparks though... thinking it was just a funny quirk of the '86 and later RX-7, or something.
I think it's just a way for RX-7 owners to feel good about giving each plug its own coil, even though leading plugs do 99% of the work, making trailing unnecessary to upgrade.
Of course this is mainly speculation. Who knows; that system *might* at least offer an LT split. I seriously doubt the brainchild behind it allowed for the dual leading sparks though... thinking it was just a funny quirk of the '86 and later RX-7, or something.
Last edited by Jeff20B; 09-24-04 at 11:31 AM.
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09-24-04, 04:08 PM
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Originally Posted by Jeff20B
The code blue car has it. That setup doesn't give the benefits of a dual leading direct fire ignition system because it sparks the leading plugs at different times (like a stock FB cap 'n rotor setup). I would also doubt that there is an LT split due to the extra complexity it adds.
I think it's just a way for RX-7 owners to feel good about giving each plug its own coil, even though leading plugs do 99% of the work, making trailing unnecessary to upgrade.
Of course this is mainly speculation. Who knows; that system *might* at least offer an LT split. I seriously doubt the brainchild behind it allowed for the dual leading sparks though... thinking it was just a funny quirk of the '86 and later RX-7, or something.
I think it's just a way for RX-7 owners to feel good about giving each plug its own coil, even though leading plugs do 99% of the work, making trailing unnecessary to upgrade.
Of course this is mainly speculation. Who knows; that system *might* at least offer an LT split. I seriously doubt the brainchild behind it allowed for the dual leading sparks though... thinking it was just a funny quirk of the '86 and later RX-7, or something.
09-24-04, 06:07 PM
#9
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It for me is just something I want to play with and write some custom software to control Don't know, after looking at the pictures I am not sure that its going to do what I thought it would. Its more just thinking out loud at this point. Thanks for all the information.
09-25-04, 12:41 AM
#11
Sensor? You mean the CAS? It fits in the dizzy hole and no, it can't work on a stock GSL-SE without an ECU swap of some sort. The CAS outputs a 12+1 signal spread across two VR sensors (or pickups, as we call them here).
I haven't read too much about UltraMegaSquirt. Is it like MSII?
As for MegaSquirt, if you run dual leading sparks only, it will be better than what one guy did where he used four 2nd gen trailing coils; one per plug, and sparked both L and T in each rotor housing at the same time. In other words, he's got 0° split and single leading sparks. Two big NO-NOs for excellent runability. He's currently running MegaSquirt "classic" hardware (PCB version 2.2 I think) and MSnEDIS code which he modified for staged injection to work better with a stock Mazda progressive throttle body. His code, with a few tweaks of my own (to bring back fast idle functionality, which is sacrificed in spark codes to output a spark trigger signal) is what is on my MS. I don't need to output an ignition signal on my fast idle circuit thanks to my modded dizzy. It also gave me a chance to play around with the code. As for letting MS control the spark, I plan to figure out a way to have three seperate ignition channels some day for my 20B's leading plugs. You can bet they'll each have late leading sparks like all dual leading sparked 12As and 13Bs do, but at 180x120°.
In my 'newbie to MegaSquirt' opinion, I'd have to say MSnS (MegaSquirt and Spark) code would have been a better choice for his ignition, but like so many others out there, he wanted to try to get an ECU to control ignition on all four plugs. It seems to work, although it didn't run as well at certain RPMs as the old cap 'n rotor system he had previously. I don't recall specific details, and the problem may have been fixed by now, but when I found out that EDIS wouldn't be useful to my particular project, or any other (two rotor) project I may take on in the future, I decided to focus on other MS-related things for now. Anyway, if he knew what we know about rotary ignition stuff, he probably would have gone with MSnS, if not for the factor of completely removing the dizzy altogether (he had the main drive pulley machined for 36-1 teeth vs simply using a dizzy to feed the MS a 4 cylinder tach signal).
He still seems unconvinced that dual leading sparks has an advantage over single leading sparks. Heh. As for his staged injection, MSnS now has it along with even more options and is now called MSnS-extra. It's still in the early, buggy stages, but it's coming along. I only wish I could read and write assembler in order to help out the code writers.
MegaSquirt was originally a fuel-only aftermarket DIY EFI kit to replace a carb on older vehicles. It has evolved to so much more thanks to its open-source uh, Linux-like openness.
MSnS outputs an uncomplicated trigger signal which then goes into a single ignitor, then to a coil, and is then distributed through a regular old dizzy cap 'n rotor setup. In our case, that trigger signal could be fed into a J-109 or GM HEI ignitor and then to an FC leading coil, and all our ignition worries would be solved. The dwell and any other signal conditioning are handled by the ignitor, thus the stock FC leading ignitor can't be used. You could always design a circuit for it though (ask 83turbo).
By the way, EDIS is a Ford thing. It can be made to work on a rotary, but you can't get dual leading sparks out of it in its stock form.
I haven't read too much about UltraMegaSquirt. Is it like MSII?
As for MegaSquirt, if you run dual leading sparks only, it will be better than what one guy did where he used four 2nd gen trailing coils; one per plug, and sparked both L and T in each rotor housing at the same time. In other words, he's got 0° split and single leading sparks. Two big NO-NOs for excellent runability. He's currently running MegaSquirt "classic" hardware (PCB version 2.2 I think) and MSnEDIS code which he modified for staged injection to work better with a stock Mazda progressive throttle body. His code, with a few tweaks of my own (to bring back fast idle functionality, which is sacrificed in spark codes to output a spark trigger signal) is what is on my MS. I don't need to output an ignition signal on my fast idle circuit thanks to my modded dizzy. It also gave me a chance to play around with the code. As for letting MS control the spark, I plan to figure out a way to have three seperate ignition channels some day for my 20B's leading plugs. You can bet they'll each have late leading sparks like all dual leading sparked 12As and 13Bs do, but at 180x120°.
In my 'newbie to MegaSquirt' opinion, I'd have to say MSnS (MegaSquirt and Spark) code would have been a better choice for his ignition, but like so many others out there, he wanted to try to get an ECU to control ignition on all four plugs. It seems to work, although it didn't run as well at certain RPMs as the old cap 'n rotor system he had previously. I don't recall specific details, and the problem may have been fixed by now, but when I found out that EDIS wouldn't be useful to my particular project, or any other (two rotor) project I may take on in the future, I decided to focus on other MS-related things for now. Anyway, if he knew what we know about rotary ignition stuff, he probably would have gone with MSnS, if not for the factor of completely removing the dizzy altogether (he had the main drive pulley machined for 36-1 teeth vs simply using a dizzy to feed the MS a 4 cylinder tach signal).
He still seems unconvinced that dual leading sparks has an advantage over single leading sparks. Heh. As for his staged injection, MSnS now has it along with even more options and is now called MSnS-extra. It's still in the early, buggy stages, but it's coming along. I only wish I could read and write assembler in order to help out the code writers.
MegaSquirt was originally a fuel-only aftermarket DIY EFI kit to replace a carb on older vehicles. It has evolved to so much more thanks to its open-source uh, Linux-like openness.
MSnS outputs an uncomplicated trigger signal which then goes into a single ignitor, then to a coil, and is then distributed through a regular old dizzy cap 'n rotor setup. In our case, that trigger signal could be fed into a J-109 or GM HEI ignitor and then to an FC leading coil, and all our ignition worries would be solved.
The dwell and any other signal conditioning are handled by the ignitor, thus the stock FC leading ignitor can't be used. You could always design a circuit for it though (ask 83turbo).By the way, EDIS is a Ford thing. It can be made to work on a rotary, but you can't get dual leading sparks out of it in its stock form.
Last edited by Jeff20B; 09-25-04 at 12:43 AM.
09-25-04, 01:02 PM
#12
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Ah, excellent. UltraMegaSquirt should be able to read that CAS output, and allow a
leading/trailing split as well as late leading spark.
UMS is Bruce and Al's next generation MegaSquirt project. It hasn't been released yet,
but it's going to be a whole 'nuther world compared to MS. Check the UMS forum at
http://www.msefi.com for more information.
leading/trailing split as well as late leading spark.
UMS is Bruce and Al's next generation MegaSquirt project. It hasn't been released yet,
but it's going to be a whole 'nuther world compared to MS. Check the UMS forum at
http://www.msefi.com for more information.
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