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Wed Jan 14, 2009 10:39 pm

which are better, resistor type plugs or the non resistor ones?

Wed Jan 14, 2009 11:37 pm

Resister plugs are fine for cars with radios. Non-resister plugs will provide a stronger spark.

hth

Thu Jan 15, 2009 12:10 am

Adding resistance to a spark plug is the worst possible way to reduce radio interference, as it also reduces and wastes spark energy. It's just the cheapest way to eliminate radio interference for the automakers. The excessive resistance will degrade your performance. In the long run it will cost you gas mileage.

Spiral wound magnetic suppression ignition wire is a much better way to reduce radio interference, as it does it with inductive reactance which doesn't waste your spark energy.

Some resistance in series with the ignition wire is useful to dissipate reflections traveling up and down the ignition wire that could otherwise radiate electrical noise. But you only need between around 150 ohms per foot and 500 ohms per foot of resistance in the ignition wire, which doesn't result in very much loss of spark power. The resistors in the spark plugs can also fail.

Replace your resistor rotor with a resistorless rotor, or modify your rotor and bypass the internal resistor, as it is also wasting your spark power.

By using low loss magnetic suppression ignition wire, a resistorless rotor, and non-resistor spark plugs, you will have reduced your voltage losses enough that you can increase your spark plug gap by around 0.005" for improved performance.

Scott Novak

Thu Jan 15, 2009 6:32 am

I've run both in my race car and can not tell any difference in ET or MPH between resistor plugs and non-resistor plugs.

Scott. Post your dyno results to back up your claims.

Thu Jan 15, 2009 7:29 am

Seems the best place to have the resistance is in the spark plug. This explains it better than I have time to.

http://www.oldcitypublishing.com/FullText/JAPEDfulltext/JAPED3.3-4fulltext/Klimiec.pdf

...

Thu Jan 15, 2009 8:37 am

If radio interference is no concern. ( dont have a radio in the car and I don't need it, ... :) ) , would some custom made spark plug wires from copper wire and no resistor be any more efficent - getting almost 0 ressistance ? ( i think so ) - but would it harm the engine and the ignition system ?

Thu Jan 15, 2009 8:53 am

I wanted to add these to a former post that had been locked. I think Scott will especially like these:
http://www.jcwhitney.com/autoparts/ProductBrowse/s...=dbb15098g
http://www.jcwhitney.com/autoparts/Search?catalogId=10101&storeId=10101&sku=dbb903653

Thu Jan 15, 2009 10:28 am

Komissar wrote: If radio interference is no concern. ( dont have a radio in the car and I don't need it, ... :) ) , would some custom made spark plug wires from copper wire and no resistor be any more efficent - getting almost 0 ressistance ? ( i think so ) - but would it harm the engine and the ignition system ?

But the guy in the car next to you at the light may have a radio.
Or if you are at the drag strip, the ignition noise may interfere with the timing lights, and give the other guy an advantage.

Thu Jan 15, 2009 10:54 am

Actually, I think that the car's body (and engine compartment in particular, with the lid down ) acts like a sort of Faraday Cage http://en.wikipedia.org/wiki/Faraday_cage , thus, the other cars (but mine) would not be influenced by the ignition electromagnetic waves.

So - from an engine/performance point of view does unsupressed wires affect the engine ?

Thu Jan 15, 2009 11:16 am

runamoc wrote: Seems the best place to have the resistance is in the spark plug. This explains it better than I have time to.

http://www.oldcitypublishing.com/FullText/JAPEDfulltext/JAPED3.3-4fulltext/Klimiec.pdf
That paper only dealt with a resistor in the spark plugs when used with resistive spark plug wires. It does NOT show the effects when you use Magnetic suppression ignition wire with resistors in the spark plugs. Notice in the paper that there is NO inductance included in the equivalent circuit.

The paper is obsolete and doesn't have any bearing on the situation of an ignition system using magnetic suppression ignition wire.

Komissar wrote: Actually, I think that the car's body (and engine compartment in particular, with the lid down ) acts like a sort of Faraday Cage http://en.wikipedia.org/wiki/Faraday_cage , thus, the other cars (but mine) would not be influenced by the ignition electromagnetic waves.

So - from an engine/performance point of view does unsupressed wires affect the engine ?
While there is steel around the engine, it does not completely surround it and it is NOT grounded. If anything, the car body becomes an antenna to transmit the spark noise. If you have an AM radio on you can hear the noise of an automobile without suppression ignition wire driving by. It's ILLEGAL! It's considered harmful radio interference which technically is a federal felony. But you would only be charged with a felony if you interfered with police, fire or ambulance radios. There are also many state laws that prohibit generating radio noise using non-suppresssion ignition wire.

Scott Novak

Thu Jan 15, 2009 11:44 am

vwracerdave wrote: I've run both in my race car and can not tell any difference in ET or MPH between resistor plugs and non-resistor plugs.

Scott. Post your dyno results to back up your claims.
Dave,

A chain is only as strong as it's weakest link. High resistance anywhere in the chain is going to significantly reduce your spark current. If you have high resistance anywhere in the chain you will have degraded the ignition performance enough that you can't tell the difference between resistor and non-resistor spark plugs.

In your testing were you using non-resistor spark plugs, a resistorless rotor, with low loss magnetic suppression ignition wire, and a low impedance air gapped core ignition coil? The adverse effects of non-resistor spark plugs are more noticeable when using a high energy ignition system and especially with a high energy CD ignition system that produces higher current sparks. The degradation in performance caused by resistor spark plugs may not be huge, depending on your ignition system, but it is there.

With a non-adaptive ignition system with high resistance you can adjust only optimize the ignition timing for one engine condition. If you optimize the ignition system only for full throttle acceleration you may not notice huge differences in the ETs between resistor and non-resistor spark plugs. The greater differences would occur at part throttle conditions which is the way most people are driving. With the same throttle position and a better spark, the ignition timing will be closer to ideal using a non-resistor spark plug. You will have more horsepower and gas mileage at that part throttle position. Hesitation and flat spots will be slightly less and you would probably have more torque at part throttle making your vehicle more drivable.

Full throttle ETs are only part of the story. Racing only shows you the short term effects of an ignition system. It doesn't how you the long term benefits of an improved ignition system that people will see on the street.

The better your ignition system the more you will be able to notice the differences.

Resistor spark plug will NEVER improve your performance. They can only hurt performance and make your engine less reliable. It's true that resistors in today's spark plugs are a lot more reliable than the used to be, but they can still fail. So why would you ever want to introduce a part, with an additional failure mode in a race vehicle, that has no possible benefit?

Scott Novak

Thu Jan 15, 2009 11:47 am

Quote: if you are at the drag strip, the ignition noise may interfere with the timing lights, and give the other guy an advantage

You'd think the lights would be 'hard wired' to prevent such a thing from happening.

Thu Jan 15, 2009 1:08 pm

Quote: if you are at the drag strip, the ignition noise may interfere with the timing lights, and give the other guy an advantage
runamoc wrote: You'd think the lights would be 'hard wired' to prevent such a thing from happening.
I'm not sure how they are setup. It's possible that the power to the lights is hardwired. But the controllers might be susceptible to noise of they were poorly designed. Or maybe it's just an urban myth.

Does anyone know for sure how the staging lights are setup?

Scott Novak

Thu Jan 15, 2009 2:41 pm

Runboy wrote: think Scott will especially like these:

http://www.jcwhitney.com/autoparts/Search?catalogId=10101&storeId=10101&sku=dbb903653
http://www.aldor-sparkplugs.com/

The Aldor sprk plugs are nothing more than a spark plug with an auxilliary gap inside.

A fouled spark plug will allow current to bleed off before the voltage can build up high enough to spark when used with a weak ignition system.

With an auxiliary gap INSIDE the spark plug insulator, the ignition wire is isolated from fouled spark plug gap inside the cylinder. The voltage can then build up high enough to jump the auxiliary gap inside the spark plug and main spark plug gap inside the combustion chamber.

Champion used to make them. They had a U for a prefix. UL87 and UL82 for Air Cooled VWs. They will only help a weak ignition system with spark plug fouling problems.

A high energy ignition system doesn't have a need for spark plugs with an auxiliary gap. It has a much higher spark current that can blast off fouling deposits.

Scott Novak

Thu Jan 15, 2009 2:47 pm

Runboy wrote: I wanted to add these to a former post that had been locked. I think Scott will especially like these:
http://www.jcwhitney.com/autoparts/ProductBrowse/s...=dbb15098g

http://www.nologyhotwires.com/

Nology ignition wires use a technique that was used many many years ago. It fell out of favor and they have tried to revive it. Many people think it's just snake oil and that the ignition wires aren't particularly reliable. I have never tested them.

For the moment it is one of those curiosities that I may get around to testing one of these years. But until I hear some very concrete evidence that they really work well from someone credible, it's not at the top of my to do list.

Scott Novak

Thu Jan 15, 2009 3:13 pm

Scott Novak wrote: If you have an AM radio on you can hear the noise of an automobile without suppression ignition wire driving by. It's ILLEGAL! It's considered harmful radio interference which technically is a federal felony. But you would only be charged with a felony if you interfered with police, fire or ambulance radios. There are also many state laws that prohibit generating radio noise using non-suppresssion ignition wire.

Scott Novak

What about the old Model A's with the solid copper ignition setup? Are they technically illegal to operate on the road?
Mike

Thu Jan 15, 2009 3:25 pm

Runboy wrote: What about the old Model A's with the solid copper ignition setup? Are they technically illegal to operate on the road?
Mike

Almost anything that creates radio interference is illegal under federal law.

I'm not sure if the spark from a model A ignition system is strong enough to create radio interference or not. Not likely that anyone would enforce the law on a Model A anyway.

Scott Novak

Thu Jan 15, 2009 6:03 pm

Komissar wrote: If radio interference is no concern. ( dont have a radio in the car and I don't need it, ... :) ) , would some custom made spark plug wires from copper wire and no resistor be any more efficent - getting almost 0 ressistance ? ( i think so ) - but would it harm the engine and the ignition system ?
In reality, magnetic suppression ignition wires have sufficiently low resistance that they don't absorb very much of the spark power.

After you replace the OEM style high resistance ignition wire with magnetic suppression ignition wire, replace the resistor rotor with a resistorless rotor, and use non-resistor spark plugs, the major source of spark power loss is the ignition coil.

Unless you are using an ultra low loss ignition coil, there is no point in even considering low resistance copper ignition wire as it won't make any noticeable improvement.

Also, most of the ultra low resistance ignition coils that I have seen are designed for drag racing only. They will probably burn out if you run them on the street.

Scott Novak

Thu Jan 15, 2009 6:47 pm

They work. Period.

Scott, you're only a state away. You should come to Chicago,
I'll show you how fast resistor plugs can go. 8)

Thu Jan 15, 2009 6:48 pm

It's not only radio interference that car makers are worried about. Engine computers and sensors can suffer from electro-magnetic interference from the ignition system which can lead to less than optimum performance. You don't need to worry about that on most ac vw's though.