Jim, do you have any experience with multi spark systems or extended duration spark systems?
Dignini - I believe that MSD is, in fact, a multi spark discharge (MSD) system. Other than that, I do not have experience. However, a good friend is knowledgeable in things ignition, and I will ask him to log on and discuss this. Jim S.
Jim, Oh, yes. the ceramic part of the ballast resistor gets hot. Not sure what you mean by the 3 prong housing being hard to clean. This is a new unit from Superformance so everything is pristine. It's a one piece 3 pronged terminal mounted at one end of the ceramic part of the ballast resistor. The Dinoplex has a wire that goes to one of those 3 terminals and the power wire coming from the ignition switch goes to another (which leaves one terminal unused). So there is near-zero ohms resistance where those wires interconnect. At the other end of the ceramic piece is a single terminal with a wire going to the + post of the coil. As I mentioned, I'll be checking grounds as the likely culprit. Thanks for your patience on this, Bill
Hi. I'm Darryl, Jim S's friend. We installed the electro-optical ignition system in his Dino. The ignition system on cars with a ballast resistor are designed to compensate for the drop in voltage during engine cranking. The idea is that you can supply a 6 volt coil with 11 volts for a short period of time during starting to provide a strong spark without burning out the coil. After the car starts and the ignition key is released, a relay switches over to feed the current through a ballast resistor reducing the voltage to 6 volts. The coil is designed to operate at 6 volts to produce about 60,000 volts. When the ballast resistor is bypassed during starting, 11 volts in produces 110,000 volts out; more than enough to start a cold or hot engine. BTW, if someone puts a 12 volt coil on a system with a ballast resistor, they won't get a sufficient high voltage spark during engine cranking or normal running.
Bill - I thought you were referring to the old 3 conductor plastic plug connector-housing from the wiring harness to the ignition box. If the 3 spade tabs in this plug are dirty or corroded, then contact resistance increases and voltage to the electronic unit decreases. This is different than the issue raised by Jagman below, which addresses the ballast resistor. Patience not required on my part...I enjoy this stuff. Jim S.
A power wire(red) coming into the trunk from the ignition switch, that connects to the + side of the coil. Then from the same side of the coil, to the capacitive discharge box. When you turn the ignition to off, the Coil and the Box no longer get power Is that right? 'Cause that's the way mine is wired.
Thank you for the insight, never even knew what a ballast resistor was for!I've been running with a 12v (high performance coil) and no ballast resistor ever since I ditched the original dinoplex and points. Any down side to that?
You can run a 12 volt coil without a ballast resistor. The only drawback is you won't get the extra high voltage boost during cranking. If you run a 6 volt coil without a ballast resistor, you'll burn out the coil real fast.
Is this still the same thread or do we start another...don't want to upset anyone here..... So that may have been a set up for the original dinoplex and its back up coil only setup. (which never worked for me anyway! It's embarrassing push starting a Ferrari!) But my experience proves to me at least, that a modern system does not need to run on a 6 volt coil and ballast resistor, or points..........maybe Dinodriver should ditch the ballast, the 6 volt coil and simplify things a bit, just a thought
Dignini - we are following a tangent to the original discussion. The concept of ballast resistor is of interest, and as you suggest, I shall approach it in a new thread. Jim S.
jagman, thanks for chiming in on this thread. Like diginini. I always wondered about the function of the ballast resistor. Always thought it was a terrible waste of energy to be heating up that ceramic block. Now I know why. So let me see if I've got this correct. Superformance sent me a Dinoplex "kit." It contained the Dinoplex (ECU, for short), a ballast resistor and a Bosch coil (apparently, 6V. I'm not home so I can't check it.) I hooked up battery power from the ignition switch to one end of the resistor. I hooked up the specified wire from the ECU to that same terminal. So now I have 11V -12V power to the ECU and the resistor whenever the ignition switch is in the "On" position. At the other end of the resistor I hooked a wire to a terminal and attached the other end of that wire to the + terminal on the coil. With the ignition switch "On," I should see about 11V at the ECU/Battery terminal and about 6V at the other end. Correct? Now for the confusing part. I don't see a relay on my schematic that will do the switchover to 11V during start. Furthermore, if there is a relay, I am no longer hooked into the original Dino wiring harness connectors in the trunk with this new Dinoplex set-up. If the relay is there, it may not be activated during start which would explain why I don't have the relatively snappy starts, hot or cold, with this new Dinoplex set-up vs the old MSD which was incorporated into the original harness. Is this a logical analysis? Can you tell me where to look for that relay on a late Dino? Is it something I can take apart and clean-up? Love this thread. Learning alot! Bill
Bill - Dignini has raised the issue of continuing this thread on a tangent, and his comments are respected. Since you asked the question, and without any intent to upset Dignini, I will continue the discussion. Jagman's comments are to be interpreted in the context of a generalization. However, in the Dino, things are a bit different. Darryl and I had a long discussion today concerning the ballast resistor as we see it on the stock Dino backup coil. Let's first understand what the backup coil resistor accomplishes. I seek input from other electrical engineers on this topic, as the following comments are based on my best interpretation of the physics. 1) A coil is nothing but a transformer, converting 12 volts to 20,000 volts. There is a primary winding and a secondary winding. The ratio of the number of turns on the primary to the secondary determines the "step up" or multiplication factor. In every case, to increase voltage, the number of primary loops is far less than the secondary. In this case, the ratio of loops of wire for primary to secondary is 12:20,000. Thus, the length of wire used in the primary circuit is far shorter than the length used in the secondary. The electrical resistance in the primary is 1 or 2 Ohms, while the secondary, using longer, thinner wire, has a resistance of 5,000 Ohms. 2) An electrical circuit that contains a capacitor and an inductor, known as an LC circuit, in an ideal world, will contain energy forever. If one excites an LC circuit, the circuit will oscillate (referred to as ringing even though there is no sound). This ringing will continue forever unless energy is dissipated through a resistor. The ringing is not unlike that of a chuch bell. Strike it once and it rings for a long time. If there were no mechanical resistance (friction), the bell would ring forever. 3) The coil of wire in the primary circuit of the coil represents an inductor with low electrical resistance. The capacitor found on the outside of the distributor housing, together with the inductor of the coil, constitutes an LC oscillating circuit. 4) The rate at which the oscillation decays is known as the time-constant. To increase the decay rate, add resistance. The resistor acts to dissipate energy in the form of heat. With these principles as background information, I suspect that the LC circuit composed of the capacitor and coil has a time constant that remains ringing beyond the time for the next opening of the points. Hence, in a 6-cylinder engine, at some RPM, the ringing of the circuit continues until the next point opening. This can lead to spark jump across the points, and, perhaps, decreased energy stores in the coil. The "ballast" resistor found on the outside of the backup coil, I believe, is to hasten decay of the oscillation, preparing the points circuit for the next opening. One subtle, but important technical point. The resistor is in series with the coil and ground. On first pass one might suspect that this resistance decreases the voltage available on the primary side of the coil. HOWEVER, an inductor has the property that it resists inrush current. That is, when current is first passed through an inductor, the instantaneous current is zero. Hence, the coil sees the entire 12 volts. No voltage is dropped across the resistor if no current is flowing. Long winded. Sorry. Darryl's comments relate to a car that has either a relay or a separate tab on the ignition switch for starting voltage. I do not believe that this is the case in the stock Dino. More to come concerning MSD installation. This post is getting to long. Jim S.
Bill The original dino set up had back up coil only ignition option. The ballast resistor, may well have been used to boost ignition voltage when the starter was used in emmergency mode. But when the Dinoplex was in use I believe this was bypassed. Was there not a toggle switch involved? It's so long ago I can't remember.
Dignini - In fact, the backup coil and points-only system had the resistor in series with the coil. This would not have boosted voltage, and as the Dino had no relay or separate ignition switch tab for starting, the sole purpose was to hasten dissipation of the LC oscillation (as discussed below). Jagman's discussion is based more on his knowledge of Jaguars, which do, indeed, have a relay or separate ignition source for starting. There was no toggle switch. One would simply unplug the 2-connector nylon housing from the Dinoplex and plug the backup coil directly to the distributor. Jim S.
You know its just so long ago........ Thanks JS its illuminating.......I wonder how Bill is getting on with his car. He started the thread with a car that would not stop. He has regressed to a car that won't start. How about it Bill where are we at?
I revisited the electrical schematic and it all came back to me. As you noted the resistor was only on the back up coil, the coil for the dinoplex had no resistor. So Bill should not be messing with a resistor in his system. He should simply have a 12v high performance coil...right?
Actually, Guys, it's not too bad. My post #16 described my 25 mile test drive and my significant complaint was that it's much too difficult to start when it's hot. Engine "Off" works fine. Starting from cold was good but not quite as "snappy" as with the MSD. Read the post for more details. Then this very interesting subject of the ballast resistor came up. I just came in from the garage where I checked out the new coil that came with the Dinoplex kit from Superformance. It's a Bosch 221 119 030-KW12V "High Energy Ignition Coil." And below is the wiring diagram that came with the system. I have mine hooked up accordingly, which may be part of the problem based on the last few posts. Here are the voltages I just measured with the ignition switch "On" (engine not running): Between the battery terminals = 12.2V Terminal A on the resistor = 10.8V At the positive Post on the coil = 5.4V For what it's worth, here's the resistance I measured inside the coil (no power, of course): + to - post = 1.5 ohns + to center post 15.5 Kohms Am I right in concluding that I don't need the ballast resistor with the H.E. coil Superformance provided? Should I be putting the power source from the ignition switch directly to the + post? Thank you all for hanging in with me on this. Bill http://www.ferrarichat.com/forum/images/attach/jpg.gif Image Unavailable, Please Login
Bill - allow me 24 hours or so to read my MSD instruction manual. It addresses this issue, but I have it at the garage. More to come. Jim S.
You can determine if your vehicle has external ballast resistance with this simple test. Disconnect any wires going to COIL negative terminal. Reconnect battery.Turn the ignition key on but do not start the engine. Use a volt meter and read voltage between COIL positive terminal and ground. It should be about 12 volts.Then momentarily jumper the COIL- terminal to ground. If voltage at COIL+ terminal drops below 8 volts, there is ballast resistance between the ignition key and COIL+ terminal.To determine if your coil has internal ballast resistance, use an ohm meter . Coils with internal resistance will read 3 to 4 ohms from COIL negative to COIL positive terminals. Darryl S.
Darryl - Please clarify. If you remove all wires from the coil, then how will it read 12-volts at the coil terminal? I suspect you mean to read the voltage at the wire that was connected to the coil...the one coming from the wiring harness. Is this correct?? Jim S.
I edited my post. I spelled out the + & - symbols. BTW, I'm going to bring my college electronics book to the garage today. This discussion was originally titled, "Engine Won't Shut Off". I'm afraid soon we'll have a discussion titled, "Engine Won't Start".
Or how about "How to extinguish an electrical fire in a Dino trunk!" I'm waiting for Jim's analysis, but I'm thinking that all I have to do is get rid of the ballast resistor and clean-up some ground connections and this Dinoplex will be fine. It's a 12V coil, therefore it wants to see 12V on the + terminal. Bill
