2nd Gen Crank Angle Sensor on 12a for Direct-Fire
02-24-05, 07:32 PM
#1
2nd Gen Crank Angle Sensor on 12a for Direct-Fire
Hey All,
Well I figured the title might attract your attention, so let me start by dissapointing you a bit. No, I haven't done this - yet.
I remember a while back when Carl and Sterling went to Sevenstock (methinks), they came back with stories of 1st Gens running 2nd Gen CAS hooked to computers for direct-fire ignition. The more I thought about this, the more it seemed to be an awesome idea. 2nd Gen CAS are pretty cheap and easy to find, and I can't think of a better way to trigger a custom ignition setup than that.
The problem lays here: You need a computer. Most of us aren't willing to buy a Haltec Ignition computer or wire up a laptop to run our ignition, and many of us are trying to keep our cars as simple and non-computerized as possible.
What I want to do is gather some information on what kind of signal the 2nd Gen CAS puts out, and how to interpret it, as well as info on how people have gone about doing this in the past. With that kind of info, my friend Michel and I might be able to figure out a cheap way of creating a simple ignition-controller of sorts, enabling us to have yet another way to clean up the engine bay and improve ignition.
Don't get me wrong, I love DLIDFIS, and plan to do it myself whenever I get the chance, but if I can get enough info on how to do this, I'd love to see where we can run with it. It won't be as programmable or complex as a Haltec, but it won't break the bank, and can give us 12a guys the ability to play with our timing a bit electronically, and run a cool direct-fire setup.
And who doesn't want to do that?
So post what you have. I need to know who'se done things with the 2nd Gen CAS, what kind of signal it outputs, and any info and input you guys can give me about what you'd want to see out of this, or suggestions on how to do it.
Jon
Well I figured the title might attract your attention, so let me start by dissapointing you a bit. No, I haven't done this - yet.
I remember a while back when Carl and Sterling went to Sevenstock (methinks), they came back with stories of 1st Gens running 2nd Gen CAS hooked to computers for direct-fire ignition. The more I thought about this, the more it seemed to be an awesome idea. 2nd Gen CAS are pretty cheap and easy to find, and I can't think of a better way to trigger a custom ignition setup than that.
The problem lays here: You need a computer. Most of us aren't willing to buy a Haltec Ignition computer or wire up a laptop to run our ignition, and many of us are trying to keep our cars as simple and non-computerized as possible.
What I want to do is gather some information on what kind of signal the 2nd Gen CAS puts out, and how to interpret it, as well as info on how people have gone about doing this in the past. With that kind of info, my friend Michel and I might be able to figure out a cheap way of creating a simple ignition-controller of sorts, enabling us to have yet another way to clean up the engine bay and improve ignition.
Don't get me wrong, I love DLIDFIS, and plan to do it myself whenever I get the chance, but if I can get enough info on how to do this, I'd love to see where we can run with it. It won't be as programmable or complex as a Haltec, but it won't break the bank, and can give us 12a guys the ability to play with our timing a bit electronically, and run a cool direct-fire setup.
And who doesn't want to do that?
So post what you have. I need to know who'se done things with the 2nd Gen CAS, what kind of signal it outputs, and any info and input you guys can give me about what you'd want to see out of this, or suggestions on how to do it.
Jon
02-24-05, 08:08 PM
#2
My goodness, searching helps a bit 
I found this so far:
https://www.rx7club.com/showthread.p...&highlight=CAS
Gives me an idea of what we're starting with... Still need to know what kind of signal I give the ignitors, and what kind of signal those pickups give.
Turning the signals from those pickups into a reading of what degree we're currently at, and deciding what plugs to fire right now is gonna be tricky.. but the more we think about it, the more we like the challenge.
I remember seeing somewhere that an ignition system would need to figure in 720degrees, and I can't remember why.. I remember seeing a chart comparing a 4cyl ignition cycle to a rotary, and I can't remember where.. Damn my memory!
Jon
I found this so far:
https://www.rx7club.com/showthread.p...&highlight=CAS
Gives me an idea of what we're starting with... Still need to know what kind of signal I give the ignitors, and what kind of signal those pickups give.
Turning the signals from those pickups into a reading of what degree we're currently at, and deciding what plugs to fire right now is gonna be tricky.. but the more we think about it, the more we like the challenge.
I remember seeing somewhere that an ignition system would need to figure in 720degrees, and I can't remember why.. I remember seeing a chart comparing a 4cyl ignition cycle to a rotary, and I can't remember where.. Damn my memory!
Jon
02-25-05, 04:45 AM
#4
You could buy a MegaSquirt. Even preassembled, it's still going to be less expensive than a Haltech. You could run it spark only and it can control a 2nd gen leading coil assembly (quite well as a matter of fact). What's more, if you bought the it in kit form and assembled an MS yourself, you'd gain first hand knowledge of basically what goes into a unit such as what you're thinking about building.
Wow, I really learned a lot since I wrote that long post back in September. I might as well update you all with my progress. I've trimmed a couple teeth from the CAS so only one VR sensor, and therefore one CPU intput is required. The end result is nearly the same as stock, but it's more efficient to use only one of everything.
The CAS has 24 teeth on the lower wheel and 2 on the upper. It spins half engine speed so the stock CPU sees 12+1 teeth per rev. To mod it for MegaSquirt, you just remove 2 teeth from the lower wheel exactly 180° apart. This produces a 12-1 signal. Again, same result in the end; just more efficient.
In the words of Mike Robert, 2nd gen coils are awesome. I totally agree. It's super-easy to hook up a leading coil assembly, complete with stock (powerful) ignitor to the MS. The EDIS guys are really out to lunch on this one (no offense). No need for a J-109 or HEI module either. I ran some side by side comparisons on the bench of a J-109 with Diamond coil and a 2nd gen leading coil assembly. The differences were dramatic. I also hooked the 2nd gen leading ignitor to a 2nd gen trailing coil. I can tell you that as soon as I scrounge up enough spare 2nd gen trailing coils and leading ignitors, they'll replace the three J-109s and Diamond coils on my 20B.
Wow, I really learned a lot since I wrote that long post back in September. I might as well update you all with my progress. I've trimmed a couple teeth from the CAS so only one VR sensor, and therefore one CPU intput is required. The end result is nearly the same as stock, but it's more efficient to use only one of everything.
The CAS has 24 teeth on the lower wheel and 2 on the upper. It spins half engine speed so the stock CPU sees 12+1 teeth per rev. To mod it for MegaSquirt, you just remove 2 teeth from the lower wheel exactly 180° apart. This produces a 12-1 signal. Again, same result in the end; just more efficient.
In the words of Mike Robert, 2nd gen coils are awesome. I totally agree. It's super-easy to hook up a leading coil assembly, complete with stock (powerful) ignitor to the MS. The EDIS guys are really out to lunch on this one (no offense). No need for a J-109 or HEI module either. I ran some side by side comparisons on the bench of a J-109 with Diamond coil and a 2nd gen leading coil assembly. The differences were dramatic. I also hooked the 2nd gen leading ignitor to a 2nd gen trailing coil. I can tell you that as soon as I scrounge up enough spare 2nd gen trailing coils and leading ignitors, they'll replace the three J-109s and Diamond coils on my 20B.
02-25-05, 08:06 AM
#5
Checking the Megasquirt site, there doesn't seem to be an ignition controller built in... but I found a link to "MegaSpark" and "MegaJolt" add-ons, and I'm checking them out 
Thanks Jeff, I figured you'd have some great info about ignition stuff
If I'm wrong about the MegaSquirt having a built-in ignition controller, then please point the way
I still want to figure out how to simplfy and isolate JUST an ignition controller.
Jon
Thanks Jeff, I figured you'd have some great info about ignition stuff
If I'm wrong about the MegaSquirt having a built-in ignition controller, then please point the way
I still want to figure out how to simplfy and isolate JUST an ignition controller.
Jon
02-25-05, 03:16 PM
#7
vipernicus42, you're correct to think the MS doesn't have any built-in ignition drivers, because it doesn't. It's a fuel-only aftermarket ECU that just happens to be capabable of controlling spark with the addition of flashing a new firmware to the CPU and one extra component. I'm talking about adding a 1k pull-up resistor (1/4 watt, but can be a 1/2 watt if that's all you have laying around) to one of the LEDs. Oh, and a short length of wire to run from the LED to one of the output jumpers so the trigger signal will be on the main wiring harness connector for easy routing into the engine bay. When the LED is off (sending 5V to the ignitor), the coil is charging.
I'm not sure, but I think "MegaSpark" was cancelled. "MegaJoltliteJr" is an EDIS-only ECU. I'm not sure what "MegaJolt" does. Like I keep telling everybody, EDIS on a 13B or 12A is not necessary due to all the extra effort that must be spent, only to get trailing and single leadng sparks. Infact, you COULD get trailing and single leading sparks straight out of the MS without EDIS if you wanted to. It's not as difficult or involved as EDIS. So what does EDIS on a rotary do anyway? It sparks both plugs on each rotor together (no split). Well, the same can be accomplished straight from two LEDs on the MS (one LED triggers at 0° and the other at 180°). An LED trigger should be able to be split into two ignitors and then into two coils, but I won't go into the details here. Oh by the way, it's not a good idea to use a 2nd gen leading coil or any other DIS coil to two plugs on a rotor housing (ask peejay).
There is no leading/trailing split functionality out of the MS at this time. The LED spark outputs (as well as any others) are always divisible evenly. In other words, one LED can handle all the spark events of the engine, from 1 to 16 cylinders, or they could be divided by 2 if using two LEDs on a 4 cylinder/rotary (13B), or three LEDs if V6 or 20B (hehehe) or all three LEDs plus one of the unused outputs on the CPU itself (with a small bit of driver circuitry) for a V8. I suppose you could also use all four for a 26B, but then it gets to the point where two LEDs would suffice if you also used two 2nd gen leading coil assemblies. Just connect one LED to each coil assembly then to the rotors which are phased 0°/180°. This depends on how the E shaft is made, and therefore the firing order of the engine.
Lastly, I think the reason why EDIS seems so prevailant on the rotary is because the MS has been able to control it for about a year now and more people have read the documentation etc. Basically, more exposure. The easier stuff I'm talking about has only been out for a few months. Actually, the MS' ability to control one 2nd gen leading coil on its stock ignitor has been around since the original MSnS came out, like 2 years ago. Just feed the MS a 4 cylinder tach signal and it outputs the correct advance etc. It originally required the F Idle circuit though. Nowadays that's all been taken care of by the tuning software which allows you to control where to send the spark trigger signal(s).
vipernicus42, the MS is so inexpensive, I may get another one for spark control only on my planned carbed supercharger project. I suppose I could later upgrade to EFI, but I'd need an intermediate plate with injector bungs, and none of them have ports as large as stock 12A and R5 intermediate plates. I also already have the carb and a set of not-so-mildly streetported R5 side plates. The nice thing about MS spark control over a dizzy is the MS can sense manifold pressure and retard at higher boost. I'd need to locate a 12A turbo dizzy if I wanted to do it old-school. By the time I located one and bought it, I'd probably spend the same amount on an MS.
I've already gone through the learning process and am more or less aware of the MS' capabilities. No offense, but I don't think I'd want to learn another system unless it was based on MS. By the way, it's all open source so you could make an ignition-only MS with one of Bowling and Grippo's 908 CPUs and just a few other components and still be able to use the nice tuning software ignoring the fuel stuff. Holy crap, now I'm starting to think of the possibilities of a $30-$40 ignition controller that is as capable as a fully built MS. The most expensive part is the CPU at $12. I'm not sure how you'd deal with the PCB or the case though. Oh man, now I'm going to be thinking about that all day instead of porting my rotor housings for the supercharged engine.
It's a fuel-only aftermarket ECU that just happens to be capabable of controlling spark with the addition of flashing a new firmware to the CPU and one extra component. I'm talking about adding a 1k pull-up resistor (1/4 watt, but can be a 1/2 watt if that's all you have laying around) to one of the LEDs. Oh, and a short length of wire to run from the LED to one of the output jumpers so the trigger signal will be on the main wiring harness connector for easy routing into the engine bay. When the LED is off (sending 5V to the ignitor), the coil is charging.I'm not sure, but I think "MegaSpark" was cancelled. "MegaJoltliteJr" is an EDIS-only ECU. I'm not sure what "MegaJolt" does. Like I keep telling everybody, EDIS on a 13B or 12A is not necessary due to all the extra effort that must be spent, only to get trailing and single leadng sparks. Infact, you COULD get trailing and single leading sparks straight out of the MS without EDIS if you wanted to. It's not as difficult or involved as EDIS. So what does EDIS on a rotary do anyway? It sparks both plugs on each rotor together (no split). Well, the same can be accomplished straight from two LEDs on the MS (one LED triggers at 0° and the other at 180°). An LED trigger should be able to be split into two ignitors and then into two coils, but I won't go into the details here. Oh by the way, it's not a good idea to use a 2nd gen leading coil or any other DIS coil to two plugs on a rotor housing (ask peejay).
There is no leading/trailing split functionality out of the MS at this time. The LED spark outputs (as well as any others) are always divisible evenly. In other words, one LED can handle all the spark events of the engine, from 1 to 16 cylinders, or they could be divided by 2 if using two LEDs on a 4 cylinder/rotary (13B), or three LEDs if V6 or 20B (hehehe) or all three LEDs plus one of the unused outputs on the CPU itself (with a small bit of driver circuitry) for a V8. I suppose you could also use all four for a 26B, but then it gets to the point where two LEDs would suffice if you also used two 2nd gen leading coil assemblies. Just connect one LED to each coil assembly then to the rotors which are phased 0°/180°. This depends on how the E shaft is made, and therefore the firing order of the engine.
Lastly, I think the reason why EDIS seems so prevailant on the rotary is because the MS has been able to control it for about a year now and more people have read the documentation etc. Basically, more exposure. The easier stuff I'm talking about has only been out for a few months. Actually, the MS' ability to control one 2nd gen leading coil on its stock ignitor has been around since the original MSnS came out, like 2 years ago. Just feed the MS a 4 cylinder tach signal and it outputs the correct advance etc. It originally required the F Idle circuit though. Nowadays that's all been taken care of by the tuning software which allows you to control where to send the spark trigger signal(s).
vipernicus42, the MS is so inexpensive, I may get another one for spark control only on my planned carbed supercharger project. I suppose I could later upgrade to EFI, but I'd need an intermediate plate with injector bungs, and none of them have ports as large as stock 12A and R5 intermediate plates. I also already have the carb and a set of not-so-mildly streetported R5 side plates. The nice thing about MS spark control over a dizzy is the MS can sense manifold pressure and retard at higher boost. I'd need to locate a 12A turbo dizzy if I wanted to do it old-school. By the time I located one and bought it, I'd probably spend the same amount on an MS.
I've already gone through the learning process and am more or less aware of the MS' capabilities. No offense, but I don't think I'd want to learn another system unless it was based on MS. By the way, it's all open source so you could make an ignition-only MS with one of Bowling and Grippo's 908 CPUs and just a few other components and still be able to use the nice tuning software ignoring the fuel stuff. Holy crap, now I'm starting to think of the possibilities of a $30-$40 ignition controller that is as capable as a fully built MS. The most expensive part is the CPU at $12. I'm not sure how you'd deal with the PCB or the case though. Oh man, now I'm going to be thinking about that all day instead of porting my rotor housings for the supercharged engine.
Last edited by Jeff20B; 02-25-05 at 03:25 PM.
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02-25-05, 07:44 PM
#9
See Jeff? That's exactly what I'm talking about.
A small, simple, sub-$50 programmable ignition controller. If I could figure out how to bastardize a MegaSquirt for some ideas, and do it without stepping on their copyrighted toes in the process, then this could be a good thing for the 1st Gen community
I won't pretend to know alot about ignition, I'm just in the learning stages, but I'm more than willing to learn and good with a soldering iron, so I'm going to dig right into the MegaSquirt website and Google over the March Break to start trying to hammer out some details.
So if I read you right, you think that with a 2nd Gen CAS, a 2nd Gen Leading Ignitor, a bastardized/trimmed down MegaSquirt and some creative thinking we can make this work?
Jon
A small, simple, sub-$50 programmable ignition controller. If I could figure out how to bastardize a MegaSquirt for some ideas, and do it without stepping on their copyrighted toes in the process, then this could be a good thing for the 1st Gen community
I won't pretend to know alot about ignition, I'm just in the learning stages, but I'm more than willing to learn and good with a soldering iron, so I'm going to dig right into the MegaSquirt website and Google over the March Break to start trying to hammer out some details.
So if I read you right, you think that with a 2nd Gen CAS, a 2nd Gen Leading Ignitor, a bastardized/trimmed down MegaSquirt and some creative thinking we can make this work?
Jon
02-25-05, 08:13 PM
#10
Suicidal Death Missile
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I'm still trying to figure out how to hook up DLDFIS, and now there's a better way with a 2nd gen coil and ignitor....crap....back to the drawing board.
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