Also I don't doubt your claims, I'm simply stating my personal experience and opinion on the matter.

 

I posted my reply in an edit

I appreciate your explanation and thoughts.

With regards to plug tip and resistor type...that again is a good argument.

Plug tips are all fairly small...I don't know if you are trying to explain the spark causing a more even burn? Or just the spark being more concentrated? Both the large surface of the coppers, and the tipped plats seem fine to me for igniting fuel in this instance.


[Modified by Tweakmeister, 4:40 PM 2/5/2003]

 

Electrical conductivity (Sigma)
Silver: 63,010,000 /ohm.m
Copper: 59,610,000 /ohm.m
Iridium: 19,710,000 /ohm.m
Platinum: 9,661,000 /ohm.m

What this means in the example of plug tip material: nothing. The calculated electrical flow resistance of these various metals, even being the full length of the electrode down into the plug core, is nothing compared to the electrical resistance present along the plug gap. I tried an online calculator for gauging electrical resistance of the various metals at a specific cross sectional area and length, the results are as follows....

.05 in2 cross section, 5" long
Copper: 0.000066046097534235 ohms
Platinum: 0.0004075155650570073 ohms
Silver: 0.00006248227065570144 ohms
Iridium: 0.00019974672115757216 ohms

Now I'm don't have the knowledge base in electricity I sometimes wish I did, but that certainly seems like almost nothing any way you cut it. I do however have an old friend who's more than just proficient in electrical flow as he designs computer chips for a living, so here's his thoughts on the subject:




[Modified by texan, 2:19 PM 2/5/2003]

 

I have some NGK cold plugs on my SIR2 and they make it run like **** compared to the DENSO iridium I use to have in there.

 

Were both plugs the same heat range? If not, there's no point in your comparison.

 

Cold plugs? Well you shouldn't be running colder plugs.

You should use the heat range of the original plug that came in the engine from the factory. Unless you've somehow modified your engine to where you might benefit from them..

 

On an aside, do the Nology wires present any sort of benefit when used? Your implied opinion, albeit not stated outright, seems to be that they only cause problems as compared to standard plug wires. Are they just hype, or do they really work as well as claimed?

 

draco: from what I've been reading...they are mostly hype.

Texan brings up a good point about RF. I don't have any way of measuring it though.

I've called Nology in the past. The best their sales guy could give me was "we're selling these by the shipping container to Japan. obviously they must know something"


[Modified by Tweakmeister, 9:50 PM 2/5/2003]

 

getting more power from your motor means moving more air and to me those 4 prongs would restict the air just that much more than one or two prongs, eveyr little bit helps. i have ngk platinum plus 2's in my car and they work well enough for me

 

something else about the Bosch i heard from a guy at school. His brother had them in his turbo eclipse and all of a sudden his turbo was rattling and grinding. They took it apart and the turbine fins were all chopped up. Seems the plug 4 prong thingies broke off and went through the exhaust and ate it up. Tue or false, i dunno but its something to think about.

 

My background isn't exactly there either, but there's something else...
I think normal air has dielectric strength of maybe 30,000 volts per inch of gap. That's not the same as resistance. For a gap of .040 that's about 1200v. I don't know about the dielectric strength of an air/gasoline mixture at higher pressures.

But once the gas in the gap has been ionized (in other words once the spark has been established) the gap resistance is way lower than that. That's when the resistance of the plugs & wires takes over. But the spark plug electrode still doesn't have any resistance compared to 1kohm (or whatever) for resistor wires & distributor rotor, etc.

I always thought the material of the spark plug (+) electrode has more to do with heat transfer & corrosion?

 

I would have to say that was BS; there's no way it made it all the way through the engine, esp. in and out the valves, and back through the exhaust side to the turbo....

 

That's exactly correct IMO, but people often talk about copper plugs over platinum for it's better electrical conductivity. In reality the platinum is only a VERY thin coating at the electrode tip and possibly on the ground strap, the core can be made of any material you wish. Copper is what NGK uses, because it's cheap and is a great thermal conductor (read: keeps the plug tip cool).

 

NGKs for me.

Jay