Bosch coil Direct Fire
09-12-04, 07:26 PM
#1
Airflow is my life
Thread Starter
Bosch coil Direct Fire
At Sevenstock, I saw numerous cars equipped with direct fire ignition. This consisted of a 2nd gen CAS and 4 Bosch coils with coil to plug wires. What I couldnt see was how all this was controlled. Being overwhelmed by the people we met and thier cars and the whole event, I forgot to ask anyone for details on this setup. Any info guys/gals?
09-12-04, 08:04 PM
#6
Bimmer *****
is there a way for the CAS to trigger something like say a J109 ignitor? if so they could have an ignitor per coil maybe? i don't know... that sounds kind of odd to me...
09-12-04, 11:44 PM
#7
It's probably partly my fault. 
The only thing I'd worry about with all those other systems is whether both leading plugs were firing together or seperately.
We know the sound of the engine actually changes when both leading plugs fire together. And what part of a running engine produces the most sound? Well, on a rotary it's the exhaust; burning fuel to be more precise (lol valves on boingers can sometimes make quite a ruckus, but I won't go there). The change in sound output when going to direct fire (with dual leading sparks) is from that late leading spark's influence. This means it's actually burning more fuel than single leading sparks ever could alone. It makes me roll my eyes at all those systems out there that only fire one leading spark per rotor face.
For anyone just joining the forum, here is a slick little animation that Blake Qualley made showing when and where the spark plugs fire. It's a little big for dialup, but hang in there and wait for it to download (it'll play more smoothly once it finishes). There is a nice little treat near the end right before the exhaust port opens up.
http://www.rotaryengineillustrated.c...es/an-WCA.html
It's funny to think that little spark, which occurs out there all by itself, can actually have that great an impact. Well, I didn't design the engine, I only seek ways to improve it, and this is one.
The only thing I'd worry about with all those other systems is whether both leading plugs were firing together or seperately.We know the sound of the engine actually changes when both leading plugs fire together. And what part of a running engine produces the most sound? Well, on a rotary it's the exhaust; burning fuel to be more precise (lol valves on boingers can sometimes make quite a ruckus, but I won't go there). The change in sound output when going to direct fire (with dual leading sparks) is from that late leading spark's influence. This means it's actually burning more fuel than single leading sparks ever could alone. It makes me roll my eyes at all those systems out there that only fire one leading spark per rotor face.
For anyone just joining the forum, here is a slick little animation that Blake Qualley made showing when and where the spark plugs fire. It's a little big for dialup, but hang in there and wait for it to download (it'll play more smoothly once it finishes). There is a nice little treat near the end right before the exhaust port opens up.
http://www.rotaryengineillustrated.c...es/an-WCA.html
It's funny to think that little spark, which occurs out there all by itself, can actually have that great an impact. Well, I didn't design the engine, I only seek ways to improve it, and this is one.
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09-14-04, 09:50 AM
#12
Right near Malloy
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You talking about direct fire on TRAILING too? Hmmm. Sounds interesting. Can't be that hard to differentiate between which rotor is on which phase (I don't say stroke any more when talking about rotaries.)
How does the FC CAS work? I might be able to build something.
How does the FC CAS work? I might be able to build something.
09-14-04, 10:47 AM
#13
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I'm having a lot of problems with ignition lately, so maybe someone can tell if Bosch coils can be controlled by first gen igniters (the J-109 ones Jeff20B seems to love so much 
).
It might help me on the road again.
And if so, could J-109's be controlled by a Wolf 3D system?
Since the ignition guru's are all in the first gen forum (aswell as all the other good guys of course ) I might aswell ask here!
).It might help me on the road again.
And if so, could J-109's be controlled by a Wolf 3D system?
Since the ignition guru's are all in the first gen forum (aswell as all the other good guys of course
) I might aswell ask here!
09-14-04, 11:24 AM
#14
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pele - it was controlling leading *and* trailing. 4 coil packs, a CAS and some wires running through the firewall. I bet we saw a half-dozen first gens with the same set up. I can post some pics tonight if anyone wants to see what it looked like. Jeff20B - interested in seeing the setup?
If this can be done easily and without too much cost, I'd be interested.
If this can be done easily and without too much cost, I'd be interested.
09-14-04, 11:41 AM
#15
Burning Oil-Grinding 3rd
Originally Posted by slashdawg00110
p I can post some pics tonight if anyone wants to see what it looked like. Jeff20B - interested in seeing the setup?
If this can be done easily and without too much cost, I'd be interested.
If this can be done easily and without too much cost, I'd be interested.
CodeBlue had a setup that looked like this. They put it in while doing the Fuel injection upgrade on their SC.
09-14-04, 01:25 PM
#18
Uhg, it's the dreaded single leading spark per rotor face stuff that Atkins has been pushing for a while. They sell those coil packs with their Microtech ECU kits. I doubt they even have any sort of leading/trailing split.
My guess is the Microtech is set to 4 cylinder wasted spark mode so each rotor gets sparks from the leading AND trailing at the same time (thus no split), once every 180º. This is just like firing a 4 cylinder's pistons 1 and 4 together, then firing pistons 2 and 3 together 180º later. Not my cup o' tea.
I've seen the CODEBLUE car and one or two others in real life with that setup. The CB car didn't run smoothly at the BBQ when they fired it up for the crowd. It may not have been tuned correctly yet, but I would have thought they wouldn't have released the car to its owners untill it was. It also requires a laptop computer with a real serial port for any sort of worthwhile tuning in the car (I don't know if they ever did get another laptop with a serial port to replace their USB laptop). The little handheld device that is also available for the Microtech appearantly isn't as ideal to use?
Go ahead and show the pics if you want. It'll at least be educational.
Just for comparison's sake, I'm going with MegaSquirt and only have PCs to use for tuning. That means I'll need to use an invertor for the computer and monitor (I'll probably leave the monitor off most of the time). It shouldn't take long to tune, especially since the ignition side of things will be handled correctly.
They sell those coil packs with their Microtech ECU kits. I doubt they even have any sort of leading/trailing split.My guess is the Microtech is set to 4 cylinder wasted spark mode so each rotor gets sparks from the leading AND trailing at the same time (thus no split), once every 180º. This is just like firing a 4 cylinder's pistons 1 and 4 together, then firing pistons 2 and 3 together 180º later. Not my cup o' tea.
I've seen the CODEBLUE car and one or two others in real life with that setup. The CB car didn't run smoothly at the BBQ when they fired it up for the crowd. It may not have been tuned correctly yet, but I would have thought they wouldn't have released the car to its owners untill it was. It also requires a laptop computer with a real serial port for any sort of worthwhile tuning in the car (I don't know if they ever did get another laptop with a serial port to replace their USB laptop). The little handheld device that is also available for the Microtech appearantly isn't as ideal to use?
Go ahead and show the pics if you want. It'll at least be educational.
Just for comparison's sake, I'm going with MegaSquirt and only have PCs to use for tuning. That means I'll need to use an invertor for the computer and monitor (I'll probably leave the monitor off most of the time). It shouldn't take long to tune, especially since the ignition side of things will be handled correctly.
Last edited by Jeff20B; 09-14-04 at 01:29 PM.
09-14-04, 01:34 PM
#20
Originally Posted by rotary emotions
I'm having a lot of problems with ignition lately, so maybe someone can tell if Bosch coils can be controlled by first gen igniters (the J-109 ones Jeff20B seems to love so much ).
It might help me on the road again.
And if so, could J-109's be controlled by a Wolf 3D system?
Since the ignition guru's are all in the first gen forum (aswell as all the other good guys of course ) I might aswell ask here!
).It might help me on the road again.
And if so, could J-109's be controlled by a Wolf 3D system?
Since the ignition guru's are all in the first gen forum (aswell as all the other good guys of course
) I might aswell ask here!As for firing some bosch coils with J-109s, you'll want to measure the resistance and inductance of th coil primary. Ask 83turbo as he's done this sort of testing before and knows what to look for.
09-14-04, 02:13 PM
#22
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Originally Posted by Jeff20B
The ignitors in 2nd gen coil assemblies were designed to be triggered by an ECU though.
09-14-04, 03:22 PM
#23
Yes you can leave them in the coil base because there is a way to connect the J-109 to the 2nd gen ignitor for a bigger spark. The 2nd gen ignitor is capable of switching a higher amount of current than the J-109 can. Or at least fellow forum user 83turbo seems to think so. He said you can use a J-109 to send an ECU-like signal to the 2nd gen ignitor. You must install a resistor inline somewhere in the circuit. Sorry, I don't know all the detals or the rating/resistance of the resistor. I think it was supposed to be 1k or something. Anyway, the J-109 outputs a nice healthy square wave with all the proper dwell and compensation on the C terminal which the 2nd gen ignitor can use as its ECU signal, and fire the leading coil with more power than the J-109 could by itself. That's the theory anyway.
I never looked into it beyond the academic phase because I always assumed I'd just throw my currently unused MSD box onto it. However, I will inevitabely pick up another 2nd gen leading coil some day since I do need two more trailing coils for my planned EDIS6 install on my 20B (I'll only need three, and I already have one trailing coil sitting here). I might as well learn the process and possibly try it out, if I have the time.
I don't have any immediate plans to build my 12A at this time (it was going to get the MSD and leading coil), so it would be in my best interest to at least try it out, just to say I've done it, I suppose.
I never looked into it beyond the academic phase because I always assumed I'd just throw my currently unused MSD box onto it. However, I will inevitabely pick up another 2nd gen leading coil some day since I do need two more trailing coils for my planned EDIS6 install on my 20B (I'll only need three, and I already have one trailing coil sitting here). I might as well learn the process and possibly try it out, if I have the time.
I don't have any immediate plans to build my 12A at this time (it was going to get the MSD and leading coil), so it would be in my best interest to at least try it out, just to say I've done it, I suppose.
09-15-04, 09:33 AM
#24
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Because of the Late Leading, I've heard of guys removing the trailing plug on FC's and putting in a bolt to stop pinging... Does the trailing plug actually do anything?
Perhaps DF on the trailing isn't even necessary.
Perhaps DF on the trailing isn't even necessary.
09-15-04, 02:43 PM
#25
Correct. Yeah, that's the famed anti-det device.
Even on an old stock FB cap 'n rotor system, a couple dyno pulls showed trailing is only good for 1.5HP.
Here is a quote from a guy who installed a MegaSquirt on his 13B, talking about another MegaSquirt user's dyno results on a street ported 12A.
In other words, single leading sparks do 99% of the work. I think most of us here have experienced the benefits of a late-leading direct fire system so in our case, dual leading sparks do over 100% of the work. The loss of trailing in my tests couldn't even be felt on the butt dyno, but the addition of those late leading sparks could be felt everywhere in the RPM range of the engine.
If those anti-de devices weren't so expensive, I'd get three for my 20B since it's got a late leading ignition system (it's the only 20B I know of that has it, hehe). In the meantime, I'll take my chances and leave in the old trailing plugs it came with. I can't justify the parts and work required for a measily 2.0HP or so (since the engine is going to put out over 200HP in NA form, the loss of 2HP is less than 1%).
Even on an old stock FB cap 'n rotor system, a couple dyno pulls showed trailing is only good for 1.5HP.
Here is a quote from a guy who installed a MegaSquirt on his 13B, talking about another MegaSquirt user's dyno results on a street ported 12A.
Jeff,
Your butt-dyno feel wrt trailing ignition fits well with the dyno results Mike Robert logged when testing his streetported 12A on the dyno. A repeat run with trailing disconnected dropped power a tiny amount, something like 1.5 hp, or 1% as I recall.
Your butt-dyno feel wrt trailing ignition fits well with the dyno results Mike Robert logged when testing his streetported 12A on the dyno. A repeat run with trailing disconnected dropped power a tiny amount, something like 1.5 hp, or 1% as I recall.
If those anti-de devices weren't so expensive, I'd get three for my 20B since it's got a late leading ignition system (it's the only 20B I know of that has it, hehe). In the meantime, I'll take my chances and leave in the old trailing plugs it came with. I can't justify the parts and work required for a measily 2.0HP or so (since the engine is going to put out over 200HP in NA form, the loss of 2HP is less than 1%).