Coil Dwell Settings with ProTuner & AccessPort
05-30-2012, 09:14 PM
#176
You are beyond dangerous
http://en.wikipedia.org/w/index.php?title=Capacitor
A capacitor (originally known as condenser)
Last edited by TeamRX8; 05-30-2012 at 09:29 PM.
07-22-2012, 12:53 PM
#187
Start up appears to be non-adjustable..partly the reason that there appears to be slightly slower starting when the battery is low
Larger wires for the power and ground make sense...the other wires it doesn't matter
If you want to solve your power issues....just re-wire the power and grounds to the coils and don't use the OEM ones...all you need from the OEM harness are the trigger and PCM grounds
07-22-2012, 03:10 PM
#188
the OE wiring is suitable for that table, and the start-up dwell is not entirely independent
That nevers stops either the court jester or the village idiot from putting on a show ...
No surprise that Dan is the only other person smart enough to recognize the obvious though.
.
That nevers stops either the court jester or the village idiot from putting on a show ...
No surprise that Dan is the only other person smart enough to recognize the obvious though.
.
Last edited by TeamRX8; 07-22-2012 at 03:16 PM.
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L337fpc (11-17-2020)
You seem to have taken this personally
07-23-2012, 09:18 AM
#192
You're sure about all kinds of things you have no understanding of, so that's no surprise ... why don't you try it first and then maybe you will have something intelligent to say, though I won't hold my breath waiting for such an event to occur
or you try ignoring me for a change, let's give that a try and see how it goes ...
or you try ignoring me for a change, let's give that a try and see how it goes ...
07-23-2012, 03:49 PM
#193
You're sure about all kinds of things you have no understanding of, so that's no surprise ... why don't you try it first and then maybe you will have something intelligent to say, though I won't hold my breath waiting for such an event to occur
or you try ignoring me for a change, let's give that a try and see how it goes ...
or you try ignoring me for a change, let's give that a try and see how it goes ...
Why you had to go on the offensive and be an *** is something I don't understand about you. You constantly expect people to understand your message without explaining yourself properly.
07-24-2012, 09:18 AM
#194
Look, spare me the innocent babe in the woods routine. You have doggedly pursued an adversarial relationship with me. That is your right. I dish it out plenty, i get it back plenty too. Do you ever see me whine or complain. No, I just deal with it rather than run around pretending to be tongue in cheek and then crying foul like a hurt child.
If you want to play the "why" game maybe you can explain why you assume my non-specific comment was directed at you. Maybe you can explain why you drop in to threads you are supposedly parricipating in and demanding other members to re-explain themselves to you again. Why do you drop into my FS/WTB threads and pursue me with insults there? Why to you think you're above having to explain your own thoughts and ideas with anything more than a simplistic "Why?" demand? Why do you pretend that your post is just a simple question when everyone knows better? Why do you claim I crave attention yet it is you who is fixated on dishing out the attention on me? Why have you not yet learned to avoid having an emotional response to anything I post?
You want to know why, well here it is: Why do I do anything RX8 related? Why did I post a year ago in this very thread that the MM method was not correct. Why did I also post what my own viewpoint on max dwell performance is. Why do people criticize me for not sharing when they turn right around and criticize me for sharing?
Why don't you cut the BS and stop acting so innocent. There are plenty of people here who can vouch that they get their questions answered or assisted by me. You're not interested in knowing why. You just want to put me in my place as a direct result of your own petty feelings and emotions. Your only chance of achieving that is to be a pallbearer at my funeral.
If you want to play the "why" game maybe you can explain why you assume my non-specific comment was directed at you. Maybe you can explain why you drop in to threads you are supposedly parricipating in and demanding other members to re-explain themselves to you again. Why do you drop into my FS/WTB threads and pursue me with insults there? Why to you think you're above having to explain your own thoughts and ideas with anything more than a simplistic "Why?" demand? Why do you pretend that your post is just a simple question when everyone knows better? Why do you claim I crave attention yet it is you who is fixated on dishing out the attention on me? Why have you not yet learned to avoid having an emotional response to anything I post?
You want to know why, well here it is: Why do I do anything RX8 related? Why did I post a year ago in this very thread that the MM method was not correct. Why did I also post what my own viewpoint on max dwell performance is. Why do people criticize me for not sharing when they turn right around and criticize me for sharing?
Why don't you cut the BS and stop acting so innocent. There are plenty of people here who can vouch that they get their questions answered or assisted by me. You're not interested in knowing why. You just want to put me in my place as a direct result of your own petty feelings and emotions. Your only chance of achieving that is to be a pallbearer at my funeral.
07-24-2012, 10:08 AM
#195
The key posts in this thread IMO are #99 #104 #108, and #143.
The key realization in understanding dwell is that the word "coil" in reference to automotive ignition is incorrect. First, there are two wire coils. Second, there is an iron core. A better would be 'ignition inductor'. The energy for the spark is temporarily stored as a magnetic field created by the primary winding. When the current to that winding is shut off, the field collapses, generating current in the secondary winding. There are many more turns in the secondary winding than the primary, so the voltage created is much higher. If there were no iron core, the charge time, aka dwell, would be nearly instantaneous on the scale of automotive useage. However, only the magnetic field contained within the secondary winding is useful for creating the high voltage required. An ironless "ignition coil" would have to be very large. To concentrate the magetic field, a piece of iron is used. However, the domains in the iron "resist" being flipped to align with the applied magnetic field. The time required to get them all flipped is the dwell.
So how does one make an "ignition coil" that is better than stock? To increase the voltage, one increases the ratio of secondary coil windings (number of turns) to primary coil windings. It seems that pretty much all auto ignitions run ~25 kV these days, so that ratio is essentially the same for all ignition coils. The other option is to increase the stored energy, which gives a higher spark current and/or a longer spark duration. This can be done by increasing the number of turns of both windings or by using more iron. The first gets big (and increases the losses from resistance in the wire), the second increases the dwell time. It's a balance.
The key realization in understanding dwell is that the word "coil" in reference to automotive ignition is incorrect. First, there are two wire coils. Second, there is an iron core. A better would be 'ignition inductor'. The energy for the spark is temporarily stored as a magnetic field created by the primary winding. When the current to that winding is shut off, the field collapses, generating current in the secondary winding. There are many more turns in the secondary winding than the primary, so the voltage created is much higher. If there were no iron core, the charge time, aka dwell, would be nearly instantaneous on the scale of automotive useage. However, only the magnetic field contained within the secondary winding is useful for creating the high voltage required. An ironless "ignition coil" would have to be very large. To concentrate the magetic field, a piece of iron is used. However, the domains in the iron "resist" being flipped to align with the applied magnetic field. The time required to get them all flipped is the dwell.
So how does one make an "ignition coil" that is better than stock? To increase the voltage, one increases the ratio of secondary coil windings (number of turns) to primary coil windings. It seems that pretty much all auto ignitions run ~25 kV these days, so that ratio is essentially the same for all ignition coils. The other option is to increase the stored energy, which gives a higher spark current and/or a longer spark duration. This can be done by increasing the number of turns of both windings or by using more iron. The first gets big (and increases the losses from resistance in the wire), the second increases the dwell time. It's a balance.
07-24-2012, 10:22 AM
#196
In an LC circuit, if L gets larger, C can be smaller. Compared to the ancient plugs-points-condensor days, the output coil voltage and stored energy are considerably higher, hence, even ignoring engineering improvements to caps, they are smaller than before.
07-24-2012, 11:09 AM
#197
Another point of confusion = duty cycle. It's been mentioned in several threads that the primary ignition circuit can see ~12 Amps (at ~14 V) which may be too much for the little OEM wires. This ignores the fact that the primary circuit is not supplying power all the time!
duty cycle = dwell / time between ignition events.
The average current through the wires = dwell charge current x duty cycle.
The maximum useful dwell time is either the dwell time for the coil at that voltage or the time between ignition events whichever one is smaller.
If one looks at the OEM dwell table for 4000 to 9000 rpm, one sees that the duty cycle remains between 20 and 25%. The average current in the primary wires is then ~3A, ie nothing to worry about. Does Mazda fret about frying their coils at a higher duty cycle? Probably, considering the already rotten lifetime of these things.
With better coils, we can up the duty cycle. 50% gives an average 6A in the primary circuit. Ok? Yep!
American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies
Is it safe for an upregraded coil? Dunno, but probably.
TeamRX8's suggestion to use 5.4 ms for everything? At 9k rpm, thats a duty cycle of 5.4 / 6.6 = 82% which gives ~10A in the primary wires. For 20 AWG, that also gives a voltage drop of ~0.5 V which will extend the coil dwell time. (A dwell time longer than the time between firings = big problems). It works for him, but he's only running at high rpm for 2 minutes at a time. I wouldn't go that far with a track car running high rpm for extended periods.
YMMV.
duty cycle = dwell / time between ignition events.
The average current through the wires = dwell charge current x duty cycle.
The maximum useful dwell time is either the dwell time for the coil at that voltage or the time between ignition events whichever one is smaller.
If one looks at the OEM dwell table for 4000 to 9000 rpm, one sees that the duty cycle remains between 20 and 25%. The average current in the primary wires is then ~3A, ie nothing to worry about. Does Mazda fret about frying their coils at a higher duty cycle? Probably, considering the already rotten lifetime of these things.
With better coils, we can up the duty cycle. 50% gives an average 6A in the primary circuit. Ok? Yep!
American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies
Is it safe for an upregraded coil? Dunno, but probably.
TeamRX8's suggestion to use 5.4 ms for everything? At 9k rpm, thats a duty cycle of 5.4 / 6.6 = 82% which gives ~10A in the primary wires. For 20 AWG, that also gives a voltage drop of ~0.5 V which will extend the coil dwell time. (A dwell time longer than the time between firings = big problems). It works for him, but he's only running at high rpm for 2 minutes at a time. I wouldn't go that far with a track car running high rpm for extended periods.
YMMV.
Last edited by HiFlite999; 07-24-2012 at 01:19 PM.
07-24-2012, 01:12 PM
#198
one day on this forum I am going to be able to ask a question without being called an idiot.
I am simply trying to learn by asking questions.
What is your problem Mark? Are you above being asked a question?
Hiflite thanks for your response.
Hey Dan- i dont have any power problems and I have replaced those wires/ grounds etc long ago. I was just curious and thats why I asked. I choose to go a different route rather than adjusting dwell
I am simply trying to learn by asking questions.
What is your problem Mark? Are you above being asked a question?
Hiflite thanks for your response.
Hey Dan- i dont have any power problems and I have replaced those wires/ grounds etc long ago. I was just curious and thats why I asked. I choose to go a different route rather than adjusting dwell
07-24-2012, 01:48 PM
#199
one day on this forum I am going to be able to ask a question without being called an idiot.
I am simply trying to learn by asking questions.
What is your problem Mark? Are you above being asked a question?
Hiflite thanks for your response.
Hey Dan- i dont have any power problems and I have replaced those wires/ grounds etc long ago. I was just curious and thats why I asked. I choose to go a different route rather than adjusting dwell
I am simply trying to learn by asking questions.
What is your problem Mark? Are you above being asked a question?
Hiflite thanks for your response.
Hey Dan- i dont have any power problems and I have replaced those wires/ grounds etc long ago. I was just curious and thats why I asked. I choose to go a different route rather than adjusting dwell
A couple of things. First when rewiring, it's best to run the new primary wires along the original path. Why? The current in the wire is pulsed, AC-like, not DC. In AC circuits, the power is not carried by the wires, but by the electromagnetic field between the wires. ( Poynting vector - Wikipedia, the free encyclopedia ) . When you run the wires together (even better as coax) this field is harmless. If you separate them, it can cause interference with other electronic devices as well as dissapate some of the energy into other objects rather than its intended destination. Admittedly this may be more of a theoretical concern or a practical concern only to those listening to AM radio.
Secondly, it's not at all clear whether upgraded coils will result in an upgraded spark without dwell adjustments. If the dwell time of the new coil is the same as OEM (~3 ms), then probably the new unit is generating more power by using more windings in the primary and secondary coils and the amount of iron remains the same. In this case, the upgrade probably is an upgrade even with the stock dwell.
If, on the other hand, the upgraded unit has a longer dwell time, it probably gets its greater power at least in part, from having more iron. In that case, using the original dwell time may result in little, no, or a negative gain over stock, depending on the construction details.
07-24-2012, 08:01 PM
#200
yessir --i grew up around cars in the 50's and 60's--the am radio would sing at times
Get a 58 oldsmobile and a spray bottle and watch the fireworks around the ignition system too.
very good points.
Very true about what you said concerning the actual coil output. You did leave out one option though in which the dwell time can remain oem yet an increase from the coil can be realized. Increase the voltage going to the coils.
1 to 2 volts increase to the coils primary supply wire can have very good results without increasing dwell. A host of factors have to be considered before you do this--including coils rise times, wiring, etc etc. It is an option. Admittedly it is easier and cheaper just to increase the dwell!
Get a 58 oldsmobile and a spray bottle and watch the fireworks around the ignition system too.
very good points.
Very true about what you said concerning the actual coil output. You did leave out one option though in which the dwell time can remain oem yet an increase from the coil can be realized. Increase the voltage going to the coils.
1 to 2 volts increase to the coils primary supply wire can have very good results without increasing dwell. A host of factors have to be considered before you do this--including coils rise times, wiring, etc etc. It is an option. Admittedly it is easier and cheaper just to increase the dwell!
