WeaponX_Perf

Actually, chew on these points.

1) Resistance must be overcome by the ignition coils in the ignition circuit. This means there is a voltage (power) drop across all the resistances in the circuit.

2) Energy does not 'slow down' with added resistance in the circuit since resistance in electronics typically acts as a device to lower voltages at the output.

3) The voltage required to jump the gap does not change regardless of the resistance of the spark plug. However, if resistances are added in the ignition circuit the moment the spark starts the ignition coil must now increase overall voltage to sustain power at the spark gap vs having no resistances at all. Keep in mind, at this point, the resistance in the spark plug is now acting as a voltage divider decreasing voltage and power at the gap. With increased voltage demands (when the spark is arching) available amperage also goes down in the circuit meaning less power at the gap.

4) In either case, the spark gap has infinite resistance until the coil starts the spark. When the spark starts the circuit is complete and ohms law now applies to the circuit. When the spark starts the circuit resistance drops substantially. From infinite resistance to >100,000 ohms. If we add resistance of a typical vehicles OE wires (~10,000 ohms), and resistance of a typical A/C Delco spark plug (~10,000 ohms) overall circuit resistance jumps up 1/5th the bridged gap resistance and both components, spark plug wires and spark plugs, reduce available energy in the gap.

When the A/F hits the spark resistance drops to approximately 1000 ohms. Overall circuit resistance with the wires and spark plug wires is now 200 percent higher then the resistance at the gap meaning most of the power is now dissipated by the resistance of the wires and spark plug. Some may say that the point is moot since when the A/F hits the gap the flame starts.. but... if you start a fire does it burn faster and more complete in a small time frame if you start it with a spark or hold a blowtorch to the wood?


I agree with this, a larger flame kernel should also allow for a more complete burn of fuel in the combustion chamber. This usually equals more horsepower because of a bigger overall explosion.

Anyone who disputes that a low resistance spark plug doesn't output a bigger spark should install one with your ignition coil wire pulled off the cylinder. Plug in a non-resistor spark plug and ground the threaded body to chasis and watch the spark. Do the same with a resistor style spark plug such as an NGK TR6. Observe the results of the spark kernel with your own 2 eyes.

I have an independent dyno that was performed by a super moderator here at LS1tech.com in regards to this. I need to be careful posting this since I don't want to seem as though I'm advertising so moderators please let me know if this is over the line and I'll remove, or you can remove, the dyno.

The tests used a brand new set of NGK TR6 resistor style spark plugs on a healthy LS7 engine. 3 baselines were performed with the NGK and then again performed with a high performance set of non resistor spark plugs we supplied.

There are a couple areas in the band the low resistance plugs show anywhere from 8-10rwhp with just a spark plug swap and anywhere from 8-15rwtrq. Minimum gain was about 4-5 engine hp through the band. Only thing changed were the spark plugs.

99blancoSS

iTrader: (115)

If anyone is interested I am offering the WeaponX Iridium spark plug. I have some more testing going one but do not want to hold back any longer on these. So they are now available from me

EdmontonSS

Take a spiral core wire which measures very low resistance with an ohm meter, if RFI noise is created by high current flows, how does a spiral core wire suppress this noise? (Hint: inductive reactance)

There is no resistance for the coils to overcome until current starts to flow. The resistance present between the coil secondary and the plug gap will slow the collapse of the magnetic field established in the coil, but will not limit the total energy available at the plug (excepting the very small heat losses across the resistances - about 1 watt for a couple milliseconds when the plug is firing with a stock wire). I imagine the inductive reactance of a "low resistance" wire creates about as much heat (and equivalent impedance).

This is excepting solid core wires of course, which I personally would never run near a computer controlled engine. Not that you can't, but I don't feel the risks worth the rewards.

I apologize for oversimplifying when I said the gains made from the 10 ohm wire as opposed to a 5000 ohm one would be "negligible" without bringing up the effects of the inductive reactance.

The amount of energy available to the plug from the coil is fixed, the rate of discharge will slow down with increased inductive and resistive loads on and in the secondary windings. The resistors "slow" the current flow, but do not "effectively" drop the voltage. The resistive values would have to be much higher to effectively drop the voltage available to the plugs.

Agreed, on all points. However, I do not believe these losses are much more than "negligible".

With no consideration of inductive loads, note that original LS1 wires measure between 300-400 ohms. I agree that relative to a solid core wire and non-resistor plug, you might see a difference of 10% in current flow through the plug gap (certainly not 20%). Also keeping in mind the coil secondary has a resistive (and inductive reactance) value as well.

I would recalculate using ~20,000 ohms for the voltage drop at the current flow across the plug gap and a 400 ohm wire.

We're trying to avoid "explosions" (detonation), we do want to start out with a bigger flame kernel, so the cylinder reaches maximum pressure sooner after the initial spark, this allows us to retard timing and still get peak cylinder pressure in the right window of time on the downstroke.

With good fuel and advancing the timing a couple degrees, I suspect the TR6's might have made similar power (but not quite as much, as any "burn" occuring while the piston is rising, is working against the rotation of the engine). However, the the higher energy plugs may not see any additional horsepower increases with more advanced timing. The advantage to the higher energy plug may be that the horsepower increase is realized without having to increase detonation resistance.

LS1-450

iTrader: (33)

Great news. You may want to announce in the external engine sections as well. The other point not mentioned in this thread is the tip design, of which looks as though it's a contributing factor to the performance of this spark plug.


The point I've noticed w/ the WeaponX plug is the easier to tune idle & better power from low idle through early part throttle acceleration up to legal speed while street driving, without any timing changes. This is a similar benefit noticed when I first drilled the ground lead & dimpled the elctrode of an NGK. The difference is that the WeaponX plugs replaced the drilled & dimpled NGK's & a further improvement is realized in the area described.

WeaponX_Perf

Yes, I apologize for simplifiying reactance as well, you are correct. The secondary magnetic field of the LS1 coils may collapse at a different rate depending on certain resistances. Typically, when there is energy, electricity does not slow down. Seeing as a magnetic field regulates the power in an ignition system, the collapse of this field determines the energy into the spark gap.

Also, just so we can compare apples to oranges I am curious to know which load your using and your calculations for total ignition voltage, amperage and time into said load so I can see how you came up with a loss of 1 watt. Basically what percentage loss are you claiming from the source power?

If your telling me one watt, I would assume that you meant from a standard LS coil at a standard dwell time which we measured at 20-24mJ into a 50pF load. If it is me, with my data, I would convert your 1 watt into about 2mJ of overall energy loss across the time of 2mS. Basically 1 watt equals about 10% overall system energy for the duration of the spark.

I agree about the risks of using a solid core wire. I also agree that the reactance of a "low resistance" ignition wire also exists but I disagree to the extent of the impedance. Infact, some of these low resistance wires don't make much of a magnetic field at all. This can often be seen on the dyno when tuners can't get an rpm reading using aftermarket low resistance wires. (no magnetic field to pull a reading from)

Whenever the windings become more dense, the resistance of the wire in question rises, typically meaning more impedance. When the windings increase so does the resistance and so does the inductive reactance and overall impedance in the wire when electricity flows. So there should also be electrical gains in aftermarket wires due to less hysterisis losses above and beyond the normal resistance losses. I would also assume that the ferromagnetic materials used in wires, is not that great since it needs to be maluable making hysterisis losses even greater.

Yes, looks like we both made that mistake. It is one of those things meant for advanced discussion only.

The amount of energy from the coil is fixed but I think we both agree that power at the gap will suffer when adding system impedances. It is impossible to have a series circuit with resistances where power at the spark gap will not drop. If you have an impedance, there is a voltage drop across it.

By lowering impedances in the system current flow in the plug gap will increase, if it is "negligible" I would disagree but negligible to you may not be negligible to someone else. It's all in the eye of the beholder. Personally, if I can see a rwhp gain, whether it be by detonation resistance and being able to bump up timing, or through a better overall combustion, I would personally consider that it is not negligible.

Infact, just for something to chew on about the subject of spark. I just spoke with an engineer at Nissan powertrain concerning spark plug design. Their NGK spark plugs cost over $10 each because of the design characteristics. They wanted to cost cut because of the high price of the spark plugs they use. This, and customers rarely bring the vehicles to Nissan for servicing because end user cost is $15 or more per plug. They ended up refusing to let their dealers stock a copper replacement and are still using the same plug because of the differences in engine power and economy. I also know that they do extensive testing in engine management when anything is changed with the engine. They actually recalibrate the engine management even if a pulley is changed on the accessories. So...!?? (shrug) Take the information for what it's worth. The added spark, or flame front improvements, justified a multi million dollar capital loss.

It was meant as a common example, as you stated, there are inductive reactances involved here as well. A 400ohm wire can turn into a 50,000 ohm inductive load if I really wanted it to.

Wooo... never meant detonation. When I said explosions, I meant the power stroke which is an ignition of a flamable mixture, but without the shockwave (detonation). If that is what LS1tech.com relates to explosion, I am sorry for the mixup. Every site has it's own "terms" so to speak.

Not sure as this was already a tuned vehicle. Maybe the moderator could jump in and let us know if they had previously played with timing for best overall results with the TR6's. I think the vehicle was dialed in on the TR6's.

Also, that is a good point, a bigger spark kernel also increases detonation resistance since the hotter spark can ignite leaner air fuel mixtures without detonation.

Yes, that is a very big point we should discuss as well. Tip design plays a large factor in flame front propagation and voltage requirements at the gap.

WeaponX_Perf

Since LS1-450 has a great point in regards to tip design I'll explain why certain electrodes are better then others to the best of my ability.

Perhaps one of the largest mis-conceptions in the industry is that since copper conducts better then iridium it makes a superior spark plug. While copper conducts better, conduction is not a contributing factor to creating, or ionizing a spark across the gap. We are trying to create a spark more efficiently not conduct electricity for large durations of time. 95% of all new engines come with a fine wire spark plug for a reason. Better performance and life span.

Tip design primarily plays a large role with voltage at the gap. Typically, a 2.5mm center electrode would require up to an additional 5000 volts at the gap to create a spark vs an iridium fine wire design. This is because electricity can jump from sharp edge to sharp edge easier then wide / blunt edges. This is apples to apples, in the same operating environments at the same gap size.

The fine wire design therefore has 3 main positive points over a standard copper design.

1) It does not shroud the flame kernel as much as the larger 2.5mm copper designs allowing for faster flame front propegation. This allows for a more efficient / faster combustion event.

2) Due to it's smaller size it does not pull as much heat energy away from the initial flame front again allowing for a more efficient combustion event.

3) If we can reduce the voltage requirement by up to 5000 volts at the gap vs a copper spark plug you therefore increase the available amperage at the gap. This has major benefits.

a) Voltage output from the ignition coil is not infinite so by lowering the voltage requirement at the gap you can now widen the spark gap. This is because a larger gap demands a larger voltage requirement from the ignition coil. This allows the iridium fine wire design to support larger gaps then the gaps provided by a standard 2.5mm copper design.

In a nut shell, since gap size can increase with a fine wire iridium you are able to create a bigger gap, with the same voltage requirements as a copper plug at a smaller gap size.

b) In an abusive environment where the voltage requirements are higher then normal, for example forced induction, an iridium fine wire design allows the ignition coil to work and ionize the gap (create a spark) easier then a 2.5mm center electrode allowing for increased gap sizes and/or hotter sparks at the same gap size.

4) Since iridium deteriorates less rapidly then a copper design the cost vs performance outweighs the less expensive spark plugs. A typical iridium design lasts for 60,000 miles where a typical copper spark plug lasts for 10,000 miles. That is 6 spark plug changes plus the time and effort changing the spark plugs. In testing, an iridium design with 60,000 miles will still fire better then a brand new standard copper spark plug.

Also, on the subject of a non-resistor spark plug and spark plug life expectancy. Spark plug life can increase when a non-resistor spark plug is used. NOTE: This is only as long as proper materials are used to combat the added energy at the spark gap. By adding amperage you have added spark plug erosion at the gap which must be taken into consideration.

Typically the resistor pill internal to the spark plug (carbon) breaks down when electrons run through it. This is normally the first device to fail in a spark plug and in spark plug wires (carbon cores). This is also why GM typically considers carbon ignition wires as consumable items. This often leads to internal arching in the parts and increased resistance levels in the equipment over time. This is why pro racers replace spark plugs after every run, lost energy due to raised resistance levels and voltage requirements at the gap (due to erosion at the tip). They understand that the carbon pills and copper electrodes break down causing them to loose those tenths of a second.

Anyway, thought I would add the info incase anybody was interested in why different electrodes perform better then others.

LS1-450

iTrader: (33)

Good information, Thank-you.

EdmontonSS

I'm sorry, I don't remember how I figured 1 Watt at the time, but it is certainly a rough estimate. One day, if bored, I may scope the voltage drop and current flow through the wire and integrate the two (I do have ready access to required equipment). Assuming a coil of 98% percent efficiency it would be easy to determine the wattage of the secondary using the primary voltage and dwell times. As I mentioned before, I somehow came up with a 10% figure myself. Loses through the spark plug will be much more difficult to determine.

If you look at an inductive pickup clamp on a timing light (or the clamp for a dyno), it is basically a ferretic toroid with another coil wrapped around the toroid. As the current in a typical spark plug wire flows straight through the ferrous toroid it induces a current via the "right thumb rule" in the toroid which then creates a voltage across the coil wrapped around the toroid. The coil is typically wired to trigger transistors in the electronics of whatever device you're triggering. The transistor triggers the timing light or dynamometer circuitry as required. As a "spiral core" wire does not flow current perpendicular to the clamp's ferrous toroid, but parallel to the toroid, the "right thumb rule" does not cause a current to flow through the toroid (thus preventing voltage to be created across the clamp coil, and so-on). The inductive clamps used are basically CT's but the current flows the wrong way in a spiral core wire. The higher quality spiral core wires claim more wraps per inch, making the problem worse as the current flow is even less tangent to the clamp.

Talking about voltage in an ignition system is like speaking of "boost" in a forced induction application. I think its easier to think of current flow (just as the forced induction guys should worry about "air flow", easy to figure by use of "horsepower"). The coil will have fixed amount of energy to deliver. There will be some heating losses through the plug wires and (resistive) plugs. You will drop instantaneous power at the gap with more resistances inline to the gap, but total spark energy will remain similar excepting the heat losses due to extra resistance. I do know that, for a spark to ignite a mixture you need a combination of heat (current flow) and duration (time) of electron flow across the gap of the plug. You need enough heat to start a chemical reaction between the fuel and air mixture, you also need the current flow to be there long enough to excite enough of the air and fuel molecules. At very low cylinder pressures, and leaner mixtures, longer duration sparks are required. At high cylinder pressures, high turbulence (high rate of "airflow" through the spark gap), and richer mixtures a shorter duration, but "hotter" spark is ideal. The ideal balance between the two, and how to exactly "tune in" secondary resistance for the ideal is far beyond me. Note that factory ignitions are universally inductive (longer durations, lower current across the gaps), for better idle quality, allowing firing of lean mixtures at idle and part-thottle, more complete burns for emissions, etc. Whereas most performance ignitions are capacitative discharge for a shorter, but hotter spark, giving the advantage of getting to MBT timing with less spark advance, as discussed previously.

Obviously, (if it hasn't already shown through) I have a huge beef with people picking performance ignition components based solely on "resistance" as measured with a $10 Ohmmeter. As far as I know the only way to reduce RFI noise is to reduce current flow, either through resistance or reactance. The spiral core wires trade resistance for reactance for the most part, as far as I know. Though the spiral core wires may put the magnetic fields at "right angles" compared to a standard wire, I feel the only way they can possibly dampen the fields is with equivalent inductive reactance to whatever resistance they may have eliminated. There may be a huge piece to this puzzle I'm missing, but current flow induces an electromagnetic field, the only way to reduce the intensity of the field is reduce the current flows one way or another. Another method that may be worth pursuing would be a "shielded" solid core wire. This won't prevent the creation of the RFI as such, but would protect the surrounding electronic components.

In the "advanced" forum, I think some people do differentiate between "explosion" and "burn", I do, didn't mean to pick on you over that, but dislike the term explosion when referring to what should be a "controlled burn".

What I meant by, we'll say a more "powerful" spark (heat and duration), was that...

If you fire a mixture at 28 degrees, the flame kernel is expanding while the piston is rising for 28 degrees of crank rotation (obviously). This causes higher pressures in the rest of the cylinder with unburnt mixture during that time period, increasing chances of auto-ignition in one or more other parts of the chamber (which would then usually cascade into the event called detonation). With a more powerful spark the timing can be made less for MBT, (maybe 26 degrees?) reducing the chances for detonation solely because the unburnt mixture should be under slightly less pressure for a shorter amount of time (pressure and time equals heat) when the piston is at the same position of travel. Sorry if this is doesn't make sense, I'm not sure I'm explaining the concept well. But my remarks has nothing to do with air/fuel ratios.

You may not believe this, but, you might want to look at the effect the metallurgy of the plug has on the kV demand of the plug in the same conditions with the same tip design. I don't have any explanation, but I have knowledge of experimental results that show it takes significantly more kV to ionize the gap using a platinum plug than a copper (how much more I will keep to myself, as it seems incredulous a change of material would change the demand voltage). I am a believer in iridium myself, running TR55IX gapped to .035".

I believe the biggest scam plug ever, behind the Splitfire (and only because of the outrageous claims), is the Bosch Platinum +4. as even the Bosch Platinum +2 is obviously a better plug for performance use, and cheaper to boot. I personally believe that platinum plugs are useless unless you have a poorly tuned, overly rich, likely carburated, oil burner of an engine.

WeaponX_Perf

I'm glad I could share some of my knowledge.

OK so we can agree that there is a minimum 10% gain in energy.

Yes, I understand how the pickup works. The right hand rule doesn't disprove this since the wire is still being wrapped in a forward direction. Current is still flowing in the same direction as the carbon wire. Just because the wire is wrapping it doesn't mean electron flow and overall direction isn't the same. If we take a carbon wire, or any wire, and wrap it in circles, or make it squiggly, placing a clamp over it will still provide a magnetic field. Usually the more the wraps the greater the field. This is the same concept as an ignition coil or making a magnet by wrapping some wire around an iron nail. The more the wraps the greater the field and the field that is created can be read around the wire. (image attached)

I like to think of voltage and amperage like water in a pipe system. The size of the pipe is voltage and the amount of water running through it is amperage. You can have a large pipe with little to no amperage (water) running through it. Throwing a resistor in the pipe is like having a water leak in the pipe.
Like we discussed, about 10% of the energy (amperage) is lost due to these leaks (resistances), or in your example heat losses.

Yes the jury is still out concerning which ignition type is the overall best. Inductive ignitions have longer discharges by nature which are best dialed in with the ignition coil design and dwell time.

I see it strikes a nerve but even you agree that a carbon suppression resistor reduces current flow and drops system energy without changing anything else so it does have some merit. That being said the ohmmeter does have it's place but I agree that there are other variables to take into consideration when it comes to ignition wires.... but even with them an ohmmeter can prove to be useful at some point.

There is a balance to everything we speak about. Resistance, reactance etc all play a role, one is not more important then the other and each is important to discuss in the system. I personally have tested several worn wire sets that measured over 100,000 ohms, or infinity (open circuit). Clearly past their life expectancy. While measuring resistance may not prove to be as useful when wires are new for a pure performance advantage, because of what you say about reactance, it can serve as a guideline for when it's time to replace the wire set. Replacing a worn wire set should provide performance benefits. Even GM acknowledges that wires used by them are a disposable item. A spiral core wire will, when made properly, last longer then it's carbon equivalent and prevent further heat loss. Just so you know, we don't make wire, so I have nothing to benefit from stating my opinions on ignition wires.

Well sure it does to some degree, but a 0.5mm fine wire copper spark plug would last less then a dyno pull before the plug needs to be replaced due to electrode erosion. The voltage demand by using a smaller / harder iridium tip that can last vastly outweighs the demands of a standard 2.5mm center electrode, regardless of metallurgy. This is where iridium becomes superior, strength and size of electrode vs the copper spark plug.

I agree, there is no such thing as a spark plug that multi-sparks because there is more then one electrode. That is a plain out lie. Our design eliminates the multi electrode, largely due to more materials in the way of the flame front and it's harder to get the A/F to the spark kernel with extra electrodes in the way.

but.... in fairness to the multi electrode spark plugs there does seem to be some advantages

If for some reason one electrode gets out of spec / worn the other electrode is there to take up the task. This can improve life expectancy and may improve performance as the plugs life gets old. Also, the area with the most fuel would tend to strike the spark first, which may help performance since the area coverage is greater, but that same area coverage shrouds the flame kernel... so..... as far as a pure performance advantage from the get go? We prefer to use the standard J-gap with a fine taper ground electrode, it has a good balance.

As for a fine wire plug, when used properly it does work, there are no questions about it. OEMS wouldn't pay a premium for a fine wire plug if there were no benefits over using a 10x cheaper copper plug. Especially if all they had to do was tune for the copper plug. It just doesn't make good business sense to spend money for nothing unless there is a good tradeoff for the expenditure. GM are the judges, jury and executioners when it comes to which plug goes in their engines and I can assure everyone that they have done extensive testing before ever jumping on the platinum bandwagon for the price of entry. I happen to agree with many of the findings and since we don't have to follow federal guidelines (FCC), there are further advantages.

99blancoSS

iTrader: (115)

I've got several sets of the Weapon X iridium in stock if anyone is interested. Right now they are selling below the cost of a set of NGK iridiums These are heat index 6, same as ngk tr6.

WeaponX_Perf

Just so everyone is aware. People running a modified LSx engine running the TR55's we usually recommend the heat index 6 plugs since the spark is hotter on our design. This keeps tip temperature optimal. Heat index 6 is ideal for most individuals except those running a highly modified engine with nitrous or with large power adders.

WeaponX_Perf

This might be interesting for people that want to know more about tip design/metallurgy.

I usually don't even bother with this subject as it is a deeply entrenched falsehood in the automotive community and I need to be careful with this explanation as many people are under assumptions that span several years, if not decades. That being said, I decided to reference an NGK website in order to show what the anatomy of a copper spark plug consists of and how it is really different from the iridium design.

To demonstrate I've taken the liberty to reference on one of NGK's websites. (image attached as well)
Take a look at spark plug anatomy here, or attached image.
http://www.ngkspark.com.au/sparkplug_tech.php#
It clearly shows the spark plug, the copper core (illustrated in the red/copper color) and the electrode which projects into the combustion chamber (silver color).

If you then scroll to the precious metal section NGK clearly shows they use a NICKLE alloy projecting into the combustion chamber for thier 2.5mm standard copper core spark plugs.

The copper core spark plug was originally an NGK design, however the electrode projecting into the combustion chamber has never been copper since copper cannot handle the stress and the errosion that takes place by the electrical strikes. The copper core was introduced in order to lower the resistance levels internal to the spark plug for better performance.

Many manufacturers, including us, use copper internal to the spark plugs meaning usually only the electrode materials, electrode designs and internal resistors are different. Everything else aside, lets focus in on which electrode material really performs better.

Well like I explained earlier, many people instinctively think copper conducts better and since we call a copper core plug, a "copper plug" even though an iridium plug uses the same copper core, people falsely presume "copper" plugs conduct better. Metallurgy plays an almost insignificant part in the creation of a spark, but for comparison sakes, it can make a small change during the time the system is sparking so lets take a look at the numbers on the iridium electrode and the nickle electrode.

The electrical resistivity of a material tells us how much resistance is present in a material per given section. The lower the value the better the material conducts.

Electrical resistivity of Nickle 69.3 nΩ·m
Electrical resistivity of Iridium 47.1 nΩ·m

These numbers can be referenced in wikipedia as well for anyone who wants to double check.

I will however qualify this with.... there is usually a 5-10% variance in these numbers because the electrode isn't 100% nickle, rather a nickle alloy mix and the iridium tip is also an alloy mix. We add small percentage of rhodium in our Iridium electrode which prevents air and water oxidation.

Electrical resistivity of Rhodium 43.3 nΩ·m

All this time the electrode, offered by the Iridium spark plug, actually out conducts the electrode in a "copper" spark plug.