Plasma Ignition | Plasma Jet Ignition

[heysoundude]

That is my original innovation on the plasma jet ignitions. However, that is best for bench tests as the HV output goes to a single spark gap.

In a car, if you do that, the the capacitor must discharge through the connection to the distributor and then through a cable to the plug - it can work, but the cables have to be near 0 ohms or it dissipates all that potential.

It's also more bulletproof to have a dedicated diode to each plug.

Of course bulletproof and reliable/repeatable are best, Aaron, but rokan is trying to get it to WORK first. Right now all that's been happening is throwing darts over shoulders hoping to hit a bullseye - rokan's not even sure if the dartboard is hung in the traditional manner. The design can be modified to suit the application, based on the specifics of the application...which nobody has for this vehicle at the moment.

[heysoundude]

Not sure what you mean about stripping it down to the basics any farther than what has already been done?
The capacitor system of connections works great on my 1995 Honda Accord but kills the ignition on my 1996 Tacoma pickup. Like Aaron mentioned earlier, there must be some kind of problem with the igniter circuit in this pickup? I'll bet if I swapped everything over to my Honda (MSD, coil and diodes) that it would work like a charm on the Honda! So something is completely different in the ignition wiring on the pickup that isn't obvious for this type of conversion??

Bingo! That's what needs sorting out so you can apply the mod appropriately, right?

[rokan]

yeah, that's not what I asked.
I keep going back in my head to the video of Peter Lindemann at a conference demonstrating how by simply by adding a diode, the dynamic of how the circuit performs is altered rather dramatically, making the plasma event rather spectacular in comparison.
There was no T-cable, no MSD box...power on, power off & spark, repeat; Simple and elegant.
Have you stripped your ignition down to the basics to replicate that?

Not sure what you mean about stripping it down to the basics any farther than what has already been done?
The capacitor system of connections works great on my 1995 Honda Accord but kills the ignition on my 1996 Tacoma pickup. Like Aaron mentioned earlier, there must be some kind of problem with the igniter circuit in this pickup? I'll bet if I swapped everything over to my Honda (MSD, coil and diodes) that it would work like a charm on the Honda! So something is completely different in the ignition wiring on the pickup that isn't obvious for this type of conversion??

[Aaron Murakami]

yeah, that's not what I asked.
I keep going back in my head to the video of Peter Lindemann at a conference demonstrating how by simply by adding a diode, the dynamic of how the circuit performs is altered rather dramatically, making the plasma event rather spectacular in comparison.
There was no T-cable, no MSD box...power on, power off & spark, repeat; Simple and elegant.
Have you stripped your ignition down to the basics to replicate that?

That is my original innovation on the plasma jet ignitions. However, that is best for bench tests as the HV output goes to a single spark gap.

In a car, if you do that, the the capacitor must discharge through the connection to the distributor and then through a cable to the plug - it can work, but the cables have to be near 0 ohms or it dissipates all that potential.

It's also more bulletproof to have a dedicated diode to each plug.

[heysoundude]

Originally with everything stock I tried the multiple capacitors to boost spark connected to the spark plug wire T which connects to the top of the plug and the other end going to ground and it barely ran with those?? Seems that when I connect anything to the spark plug wire to go to the top of the plug it just screws the whole sparking system up and starts mis-firing???

yeah, that's not what I asked.
I keep going back in my head to the video of Peter Lindemann at a conference demonstrating how by simply by adding a diode, the dynamic of how the circuit performs is altered rather dramatically, making the plasma event rather spectacular in comparison.
There was no T-cable, no MSD box...power on, power off & spark, repeat; Simple and elegant.
Have you stripped your ignition down to the basics to replicate that?

[rokan]

Hi Rokan,



Did you try the suggestions I listed in post 992 with additional capacitors and a Faraday shield to see if RFI is the problem?

Not yet, been sick

[Gary Hammond]

Hi Rokan,

Any ideas of how we can get this to work???

Did you try the suggestions I listed in post 992 with additional capacitors and a Faraday shield to see if RFI is the problem?

[Gary Hammond]

Hi Aaron,

Can you test all 4 didoes with a diode setting on a multi-meter? I don't recall if the voltage necessary to test is high enough on those meters to with these hv diodes, but it is worth a try.

Put probes one way on diode and check reading then reverse probes and check reading. Do for all 4 and see if all 4 gives the same readings.

I tried testing mine with a multi-meter and it showed infinite resistance in both directions whether in normal resistance mode or diode check mode. The forward voltage drop on these is too high to check this way. Don't remember for sure but I'm thinking it's in the 9 to 12 volt range.

The way to check these is to fasten a 1000K resistor in series with each one you want to test and then place 20 volts dc across the circuit both ways. Then by checking voltage drop across the resistor, you should see 20 volts minus the forward drop of the diode in the forward direction and zero volts in the reverse direction. And if you check voltage drop across the diode, it should show the actual forward drop in the forward direction and 20 volts in the reverse direction.

I think these are made up with several PN junctions in series to get the high voltage rating, so each PN junction forward drop (~.6 volts) is added together to get the total forward drop across the entire device.

[rokan]

Have you considered going back to basics?
As in removing (or bypassing) the MSD box, placing a diode between the primary and secondary of the coil, and maybe a capacitor across the primary?
(what if the output spikes the MSD puts out are the cause of the misfiring?)
Can you get plasma that way? Does the engine stop misfiring and run correctly?

There's only one way to find out, right? You're reverse engineering the factory ignition to implement an aftermarket solution (which I seem to recall the manufacturer couldn't help you apply to your car), and then modifying the intended purpose of that.
See if the key part of the mod (the diode) works first, then add to it. Seems (to me) to be the simplest way to proceed.

Originally with everything stock I tried the multiple capacitors to boost spark connected to the spark plug wire T which connects to the top of the plug and the other end going to ground and it barely ran with those?? Seems that when I connect anything to the spark plug wire to go to the top of the plug it just screws the whole sparking system up and starts mis-firing???

[heysoundude]

Have you considered going back to basics?
As in removing (or bypassing) the MSD box, placing a diode between the primary and secondary of the coil, and maybe a capacitor across the primary?
(what if the output spikes the MSD puts out are the cause of the misfiring?)
Can you get plasma that way? Does the engine stop misfiring and run correctly?

There's only one way to find out, right? You're reverse engineering the factory ignition to implement an aftermarket solution (which I seem to recall the manufacturer couldn't help you apply to your car), and then modifying the intended purpose of that.
See if the key part of the mod (the diode) works first, then add to it. Seems (to me) to be the simplest way to proceed.

[rokan]

Can you test all 4 didoes with a diode setting on a multi-meter? I don't recall if the voltage necessary to test is high enough on those meters to with these hv diodes, but it is worth a try.

Put probes one way on diode and check reading then reverse probes and check reading. Do for all 4 and see if all 4 gives the same readings.

I can check them but the diodes aren't the problem, it starts mis-firing before I ever get the diodes connected!? If I just hook the jumper wire to the connection at the top of the spark plug it goes stupid before anything else is connected to the end of the wire??!!

[Aaron Murakami]

Any ideas of how we can get this to work???

Can you test all 4 didoes with a diode setting on a multi-meter? I don't recall if the voltage necessary to test is high enough on those meters to with these hv diodes, but it is worth a try.

Put probes one way on diode and check reading then reverse probes and check reading. Do for all 4 and see if all 4 gives the same readings.

[rokan]

Yes and I did try them reversed and it wouldn't run at all.

Any ideas of how we can get this to work???

[rokan]

That makes things simple being positive - always my preference.

That resistance is pretty low too - looks good.

If the hv output is truly positive, then this is how the diodes should be pointed. This of course doesn't address you possible rf problem, which I'm not so sure about or igniter issue if there is one.



Just to re-confirm, is this how you have your diodes or had your diodes?

Yes and I did try them reversed and it wouldn't run at all.

[Aaron Murakami]

Here's the response I received from Ryan:
Does my Nology Profire PFC-M70 coil output HV positive or HV negative?

positive

Is my coil suitable for the MSD Street Fire MSD unit? Is it compatible with capacitive discharge?

M75 would be better, but M70 will work

What is the resistance for the primary?

.25 Ohm

What is the resistance of the hv secondary?

8 Ohm

That makes things simple being positive - always my preference.

That resistance is pretty low too - looks good.

If the hv output is truly positive, then this is how the diodes should be pointed. This of course doesn't address you possible rf problem, which I'm not so sure about or igniter issue if there is one.



Just to re-confirm, is this how you have your diodes or had your diodes?