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The ballast resistor and the coil's parasitic resistance does that. Measuring the DC resistance of the coil doesn't tell you the inductance of the coil and therefore how it will behave to a unit step... (which looks like an open circuit initially).Quote:
Originally Posted by Bitsyncmaster
Sometime it's not ignorance but rather he does not wish to deal with hard things. Take for example his view on fuel pump covers which he now suggests owners leave off and install a water dam because:Quote:
Originally Posted by DCUK Martin
taken from Farrar's blog threadQuote:
Originally Posted by content22207
Yes the inductance will change a lot when the current is changing but that is only for a very short time. The rest of the time it is DC resistance. Now if the input was a sine wave that would eliminate any DC resistance importance because the current would always be changing.Quote:
Originally Posted by DCUK Martin
I think our cars used two resistors because they could not find a coil with the proper characteristics. It would be better to use one resistor for starter bypassing with the proper coil.
Read up on the history of the Bosch Blue coil. It debuted in the late 1960's, when most ignitions were still breaker point. The Bosch Blue coil was designed to produce optimal spark from the ~6 volts primary that was then the industry standard (6 volt Volkswagen owners -- that's 6 volts car voltage -- couldn't buy them fast enough).Quote:
Originally Posted by Bitsyncmaster
Fast forward to 1981. By then, the Bosch Blue coil was looking very dated indeed. Nearly every manufacturer had upgraded primary coil voltage to at least 10 volts. Nearly manufacturer was running ~.05" plug gaps that higher voltage coils made possible.
It cracks me up when owners claim that DeLorean ignition was optimized for performance. Quite the opposite -- it was dumbed down for the coil.
Bill Robertson
#5939
Actually, my reasoning for changing the stock system is rooted in increased performance.Quote:
Originally Posted by DCUK Martin
Bill Robertson
#5939
Nothing quite like impartial and objective moderation, eh?Quote:
Originally Posted by sean
With all due respect, it is less hard (easier) to leave a stock ignition in place than it is to do the research and make the changes necessary to upgrade ignition to 1981 standards, much less 21st century standards.
Bill Robertson
#5939
It truly rocks!Quote:
Originally Posted by content22207
Regardless of everyone's position on the stock vs. modified coil/ignition, everyone should at least agree that the stock plug gap is pretty small.
As the years went on every car manufacturer has found a way to increase secondary voltage and with it the plug gap.
A stock system works well. That has been proven through millions of real-world miles cars with a similar setup have put on the road. What I don't understand is why a car company would base their 'new' electronic ignition around the use of an off-the-shelf coil. If they were putting the money into developing this new system why not develop a new a new coil to take advantage of the breakerless ignition?
Bosch wasn't the only one to do this. Ford did the same thing over here. I just don't understand why they would stop at 6-8v at the coil. They knew in the 60's that increased primary voltage was the way to go for performance and economy. They wouldn't have resorted to dual-point distributors (and the associated headaches) if they didn't.
In the 1970's Ford used 10.5 volts primary (Duraspark breakerless ignition). Plug gaps were .044".
Bill Robertson
#5939
Here's where I found the info I was basing my statement:Quote:
Originally Posted by content22207
http://www.autozone.com/autozone/rep...00c15280077d43
From the above troubleshooting guide:
"If no spark occurs, measure the voltage on the battery side of the coil.
Less than 6 volts - Repair the wire carrying current to the battery terminal of the coil and repeat test.
If voltage is 6-8 volts - Substitute, but do not install, a known good module and repeat the test. If spark then occurs, reconnect the original module to verify its being defective. Replace as required. Refer to step 10 if the battery voltage is present."
This is not a Ford document FWIW.
Automotive coils need to switch 5 to 10 amps to work. It does not mater if it takes one volt or 100 volts to get that current in the primary. The output voltage is produced when the the current is switched off (open points) so at that time your + side of the coil will be 13.5 volts no mater if you have no resistor, 1 ohm or a 1000 ohm resistor.
Give me detail - how much performance did you gain? Put your money where your mouth is....Quote:
Originally Posted by content22207
Are you calling the Society of Automotive Engineers, and nearly every car manufacturer of the past quarter century, liars? I recommend pages 53-55 (6th through 8th pages of the scans): http://dmctalk.org/showthread.php?65...ull=1#post7222
We can't really do anything about spark duration, given the small diameter of our distributor caps, but there is plenty a DeLorean owner can do to increase secondary voltage and open up his or her plug gaps.
You are wrong -- I humbly suggest that you learn to live with that reality.
Bill Robertson
#5939
Hey guys, I know I'm new around here and all but I've run a forum for the better part of 12 years so I think I'm qualified to speak on this.
You've got someone here that's posted a thread looking for some troubleshooting ideas and it has since devolved into a "my way is better" free for all. If I didn't understand the ways of the internet I'd think my thread was just hijacked for some egos to throw their weight around and I'd leave the forum with an unfixed problem and a sour taste for the Delorean community in general.
Up until my last post the conversation and the people involved were really helping me and I did improve my car. This little argument didn't help in the least. I understand the two sides, and honestly, I don't care either way nor do I care who started it. It is your car, do what you want.
All I'm trying to say is, please try to be a little respectful of what type of thread you're in before arguing. I've noticed so many troubleshooting threads never get resolved because of distractions and it is a great loss to the community. Imagine if someone had actually said "Eureka, this is what I did to fix my problem!" and the next guy searches, finds that info, fixes his issue, and doesn't have to ask the community?
You are right. Sorry, man.Quote:
Originally Posted by Kenny_Z
The problem is: some people buy a performance coil, like your Accel coil, and assume that alone gives them HEI. Doing such *HAS* led to problems in the past, like owners opening up the plug gap and creating engine misfires. Your Accel coil is probably fine, despite anything that fellow in the Mustang told you, but you do need to be aware of what it is, and what it isn't.
Bill Robertson
#5939
Yeah, I don't think it is the coil now. The new ground to the engine improved my spark which the Mustang guy may have interpreted as a bad coil. I didn't think the coil was going to give me a better spark, it really was just the closest thing I could locally get to a stock D coil once I found the cracks in my old one.
I didn't get much accomplished today because I spent most of the day working on my mom's van. She was having brake problems and mom's safety comes before the D any day of the week. I did have enough time to rig up a test ground cable before the rain started. I stuck some alligator clips on the end of a 20 foot 10 AWG cable. I stuck one end to the ground point for my headlights/cooling fans and the other end to the battery. This greatly improved my voltage drop when clicking on the headlights and AC so I know I need to continue with my plan to get a stronger ground on the front. My vent fans are still causing a massive voltage drop so I think I need to find their ground under the dash and use my test on them.
So now I have 3 questions:
Where can I find the ground connection for the vent fans?
Where the heck is the inertia switch hiding?
And what are these two disconnected wires I found?
http://uploads.m-cgi.com/kennyz/Delo...rphanwires.jpg
On an automatic those go to the bulb that illuminates the shifter.
Bill Robertson
#5939
For what its worth I have copied Bill's ignition mod, and a few others, and I do take bathes in noodles.Quote:
Originally Posted by DCUK Martin
All too often someone gets the idea that bolting in a new, different part will give them better performance, gas mileage, reliability, <blank> etc. You can fill in the blanks. If it was that easy the original manufacturer would have done it. In some cases they actually do see some improvement only because the part they replaced was old, worn, the wrong one, or defective. There is little if anything to be gained by putting "performance" parts into the ignition system. If every part you could bolt on to the car added the performance each claimed you could theoretically double the HP of the car. Who is going to believe THAT! A BIG problem with deviating from stock is that it becomes near impossible for anyone to help when the car has a problem. Too many variables and no good place to start troubleshooting. For a street driven car reliability is very important. To a big extant more important than a small, temporary increase in performance. Another thing to remember is most systems are like chains. Only as strong as the weakest link meaning if you don't improve the WHOLE system, improving one part of it does not improve what the whole system can do. As Martin said, "Show Me!" Put it on a dyno and show the numbers. Till then it is just a pretty and expensive part. I swear that my car always runs better after I clean it or change the oil. A very subjective effect. After spending money on a performance part you expect the car to run better, faster, etc!
David Teitelbaum
Pertronix coils cost about half as much as a Bosch coil -- they are a pretty and INexpensive part.Quote:
Originally Posted by David T
HEI discsussions probably should be continued here: http://dmctalk.org/showthread.php?13...tion-%28HEI%29.
Lets suppose a person wants to keep their ignition somewhat stock and wants to save money at the same time. Couldn't a persion replace a bad bosch coil with a Pertronix coil (they cost about $40) and leave everything else alone such as plug gap and resistor wiring?Quote:
Originally Posted by content22207
I kept my plug gap stock until I rewired my ignition resistor and everything seemed to be fine. Obviously you wouldn't get a performance boost but it should work just fine.
You will get a small performance boost. High winding coils produce more secondary voltage than low winding coils can from the exact same input voltage.Quote:
Originally Posted by stevedmc
Bill Robertson
#5939
I for my part only argue with Bill when he takes to his soap box with inflated opinions (expressed with suitable Bill-ish flamboyance) which are rarely backed up by engineering fact. You say "free for all"? I'd say no, it isn't. It's a "free for Bill" - at least that's how he treats the forum in general.Quote:
Originally Posted by Kenny_Z
I want a newbie searching the archives to see both sides of the coin.
*sigh*. No, I'm asking you to prove that with your ignition modification, you achieved anything more than could be achieved with new stock components.Quote:
Originally Posted by content22207
This conversation is best moved to an HEI specific thread: http://dmctalk.org/showthread.php?13...tion-%28HEI%29Quote:
Originally Posted by DCUK Martin
Please start moving the HEI discussion to where bill posted: Here
I finally beat the problem. I found that I was getting 12.35 on the battery but only 11.4 at the positive post on the right hand side of the engine bay. With the car running I got about 13.5 but this quickly fell as I turned on accessories, especially the AC, all the way to about 8 volts. As the car hunted for idle it would drop even lower. So I replaced the ground cable from the battery to the chassis (2 gauge) but grounded it to the transmission instead. To me this seemed to be way easier than trying to replace the positive cable. I figured I was going to replace it if I found the positive was the issue so I did it first. After that, I got 12.35 at the battery and 12.35 at the positive ground post. As I turned on accessories I only dropped from 13.5 volts to 12.25 at the lowest at idle (AC max, fans full, and high beams on). I also ran a 4 gauge cable from the front ground to a bolt I found (doing nothing) running through the firewall and grounded some of the underdash grounds to this terminal.
A nice drive proved out the fixes. Now if she'll stay this fixed for awhile.
Well done, bud. This 4 gauge wire - I want to see this on Saturday at the show. I'm interested in this. So you basically just re-grounded the main negative terminal of the battery to the transmission rather than the frame? In essence, you installed your own "Hervey grounding wire kit" - is that what I'm understanding ? If so, I want you to help me with my kit when I go to install it!Quote:
Originally Posted by Kenny_Z
As for the bickering, welcome to the forum, futureboy.