Like I said in another post if your plugs are easy to change use the copper plugs and change them every 30 or so. If your are hard to get to... iriduim is the way to go....
PLATINUM VS. IRIDIUM
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Originally Posted By: rszappa1
Like I said in another post if your plugs are easy to change use the copper plugs and change them every 30 or so. If your are hard to get to... iriduim is the way to go....
I would agree!
Like I said in another post if your plugs are easy to change use the copper plugs and change them every 30 or so. If your are hard to get to... iriduim is the way to go....
I would agree!
iridium is a better conductor than platinum.
It is the best tip material for spark plugs.
Copper plugs can be plain, plats, or irids. The tips are not copper.
It is the best tip material for spark plugs.
Copper plugs can be plain, plats, or irids. The tips are not copper.
Some tips of early plugs were copper, but you won't find those as often these days if at all. An Excellent Point that you bring up though.
Originally Posted By: BuickGN
I've already given my .02 a bunch of posts up.
In short, while the irridiums may still work at extreme mileages, it doesn't mean they're at their peak performance. I swapped my factory irridiums with platinums at 40K and noticed an improved cold idle. It's going on another 40K and hopefully they now make an irridium plug one heat range colder now so I can go back to them.
I think it's good to swap the plugs at sane intervals because you can see if a cylinder is having problems such as oil burning, lean/rich, detonation, etc. Then there's the danger of stripped aluminum heads with 100K+ intervals.
Be careful swapping iridium plugs for platinum plugs. Platinum has a different electrical resistance and you could be unintentionally putting more stress on the ignition coil(s). If the stock plug was iridium, you want to keep it iridium. It's a good idea (like you posted) to check the plugs at "sane" intervals, but I think replacement should be conditional. Also, Spark Plugs with Trivalent Metal Plating (superior anti-corrosion and anti-seizing properties) make it safe to use plugs up to 110k miles (According to Toyota and NGK).
I've already given my .02 a bunch of posts up.
In short, while the irridiums may still work at extreme mileages, it doesn't mean they're at their peak performance. I swapped my factory irridiums with platinums at 40K and noticed an improved cold idle. It's going on another 40K and hopefully they now make an irridium plug one heat range colder now so I can go back to them.
I think it's good to swap the plugs at sane intervals because you can see if a cylinder is having problems such as oil burning, lean/rich, detonation, etc. Then there's the danger of stripped aluminum heads with 100K+ intervals.
Be careful swapping iridium plugs for platinum plugs. Platinum has a different electrical resistance and you could be unintentionally putting more stress on the ignition coil(s). If the stock plug was iridium, you want to keep it iridium. It's a good idea (like you posted) to check the plugs at "sane" intervals, but I think replacement should be conditional. Also, Spark Plugs with Trivalent Metal Plating (superior anti-corrosion and anti-seizing properties) make it safe to use plugs up to 110k miles (According to Toyota and NGK).
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Originally Posted By: Down_South
Be careful swapping iridium plugs for platinum plugs. Platinum has a different electrical resistance and you could be unintentionally putting more stress on the ignition coil(s). If the stock plug was iridium, you want to keep it iridium. It's a good idea (like you posted) to check the plugs at "sane" intervals, but I think replacement should be conditional. Also, Spark Plugs with Trivalent Metal Plating (superior anti-corrosion and anti-seizing properties) make it safe to use plugs up to 110k miles (According to Toyota and NGK).
+1
Great Advice Down_South. ... I always check my Iridiums in the fall by taking out the 3 front plugs and having a look. I would take them all out but I can't get to the rear ones without taking off my Plenum but that's ok, the 3 in the front give me a good idea how they are fairing and if I will be stranded in the winter at anypoint.
Be careful swapping iridium plugs for platinum plugs. Platinum has a different electrical resistance and you could be unintentionally putting more stress on the ignition coil(s). If the stock plug was iridium, you want to keep it iridium. It's a good idea (like you posted) to check the plugs at "sane" intervals, but I think replacement should be conditional. Also, Spark Plugs with Trivalent Metal Plating (superior anti-corrosion and anti-seizing properties) make it safe to use plugs up to 110k miles (According to Toyota and NGK).
+1
Originally Posted By: Down_South
Originally Posted By: BuickGN
I've already given my .02 a bunch of posts up.
In short, while the irridiums may still work at extreme mileages, it doesn't mean they're at their peak performance. I swapped my factory irridiums with platinums at 40K and noticed an improved cold idle. It's going on another 40K and hopefully they now make an irridium plug one heat range colder now so I can go back to them.
I think it's good to swap the plugs at sane intervals because you can see if a cylinder is having problems such as oil burning, lean/rich, detonation, etc. Then there's the danger of stripped aluminum heads with 100K+ intervals.
Be careful swapping iridium plugs for platinum plugs. Platinum has a different electrical resistance and you could be unintentionally putting more stress on the ignition coil(s). If the stock plug was iridium, you want to keep it iridium. It's a good idea (like you posted) to check the plugs at "sane" intervals, but I think replacement should be conditional. Also, Spark Plugs with Trivalent Metal Plating (superior anti-corrosion and anti-seizing properties) make it safe to use plugs up to 110k miles (According to Toyota and NGK).
Thank you! I'll admit I'm not the most up to date with plugs. My experience is limited to racing and I had some interesting results using different plugs in my turbo car with the stock ignition and 2X the factory hp and 29psi boost but that's for a different thread.
I have iridiums back in the TL now. Found one heat range colder so I'm happy with it. Hopefully I didn't shorten the life of the coils too badly. Still plan on swapping them at 120K which would be another 40K interval though. I guess it goes along with my 3-5K synthetic OCIs.
Originally Posted By: BuickGN
I've already given my .02 a bunch of posts up.
In short, while the irridiums may still work at extreme mileages, it doesn't mean they're at their peak performance. I swapped my factory irridiums with platinums at 40K and noticed an improved cold idle. It's going on another 40K and hopefully they now make an irridium plug one heat range colder now so I can go back to them.
I think it's good to swap the plugs at sane intervals because you can see if a cylinder is having problems such as oil burning, lean/rich, detonation, etc. Then there's the danger of stripped aluminum heads with 100K+ intervals.
Be careful swapping iridium plugs for platinum plugs. Platinum has a different electrical resistance and you could be unintentionally putting more stress on the ignition coil(s). If the stock plug was iridium, you want to keep it iridium. It's a good idea (like you posted) to check the plugs at "sane" intervals, but I think replacement should be conditional. Also, Spark Plugs with Trivalent Metal Plating (superior anti-corrosion and anti-seizing properties) make it safe to use plugs up to 110k miles (According to Toyota and NGK).
Thank you! I'll admit I'm not the most up to date with plugs. My experience is limited to racing and I had some interesting results using different plugs in my turbo car with the stock ignition and 2X the factory hp and 29psi boost but that's for a different thread.
I have iridiums back in the TL now. Found one heat range colder so I'm happy with it. Hopefully I didn't shorten the life of the coils too badly. Still plan on swapping them at 120K which would be another 40K interval though. I guess it goes along with my 3-5K synthetic OCIs.
One question, suppose the platinums did increase resistance. Voltage would stay about the same but wouldn't the current go up? Just trying to figure out if that might have been the cause of the better cold idle or just the fact that it was a new plug.
I find it interesting that the spark plug wires (if applicable) have significant resistance and are different lengths and resistance goes up as a plug wears/erodes, yet a tiny amount of resistance difference in materials can foul up a computerized ignition system. Is the secondary side of the coil that smart/sensitive?
The amount of resistance in the plug is very small compare to the resistant of the air in the gap. If it really bothers you, try a smaller gap when switching from Iridium to platinum plugs.
That was my point. Switching between the two is claimed to have potential ill effects due to a "resistance difference" in the tip materials but when you factor in the rest of the system, that resistance seems insignificant. .001 difference in gap or a couple of inches of ignition wire would create a larger difference than a material change.
I'd love to read a TSB or something similar on the subject.
I'd love to read a TSB or something similar on the subject.
Originally Posted By: BuickGN
One question, suppose the platinums did increase resistance. Voltage would stay about the same but wouldn't the current go up? Just trying to figure out if that might have been the cause of the better cold idle or just the fact that it was a new plug.
That's a very good question. My understanding is that a resister "resists" the flow of an electrical current, so in effect the coil would have to generate more amperage to get the higher resistance plug to fire. I assume that a larger amount of the electrical energy changes into heat energy and this could potentially damage the coil if the amount of heat went beyond the "normal" operating temperature of the coil.
I've made the same mistake too, but it didn't seriously damage my coil and the service technician explained it to me very well.
One question, suppose the platinums did increase resistance. Voltage would stay about the same but wouldn't the current go up? Just trying to figure out if that might have been the cause of the better cold idle or just the fact that it was a new plug.
That's a very good question. My understanding is that a resister "resists" the flow of an electrical current, so in effect the coil would have to generate more amperage to get the higher resistance plug to fire. I assume that a larger amount of the electrical energy changes into heat energy and this could potentially damage the coil if the amount of heat went beyond the "normal" operating temperature of the coil.
I've made the same mistake too, but it didn't seriously damage my coil and the service technician explained it to me very well.
Originally Posted By: tom slick
I find it interesting that the spark plug wires (if applicable) have significant resistance and are different lengths and resistance goes up as a plug wears/erodes, yet a tiny amount of resistance difference in materials can foul up a computerized ignition system. Is the secondary side of the coil that smart/sensitive?
Good Point. I doubt there is such a thing as a "smart" computer at least not yet. I suppose that the engineers who make these systems have a set criteria (resistance ranges) for each component in the system. Every system is unique and I'd have to study more to figure this one out.
I find it interesting that the spark plug wires (if applicable) have significant resistance and are different lengths and resistance goes up as a plug wears/erodes, yet a tiny amount of resistance difference in materials can foul up a computerized ignition system. Is the secondary side of the coil that smart/sensitive?
Good Point. I doubt there is such a thing as a "smart" computer at least not yet. I suppose that the engineers who make these systems have a set criteria (resistance ranges) for each component in the system. Every system is unique and I'd have to study more to figure this one out.
Originally Posted By: tom slick
That was my point. Switching between the two is claimed to have potential ill effects due to a "resistance difference" in the tip materials but when you factor in the rest of the system, that resistance seems insignificant. .001 difference in gap or a couple of inches of ignition wire would create a larger difference than a material change.
I'd love to read a TSB or something similar on the subject.
True, and resistance goes up as cylinder pressure goes up. Or at least it requires more voltage to fire the plug as cylinder pressures go up.
That was my point. Switching between the two is claimed to have potential ill effects due to a "resistance difference" in the tip materials but when you factor in the rest of the system, that resistance seems insignificant. .001 difference in gap or a couple of inches of ignition wire would create a larger difference than a material change.
I'd love to read a TSB or something similar on the subject.
True, and resistance goes up as cylinder pressure goes up. Or at least it requires more voltage to fire the plug as cylinder pressures go up.
Spark happens when the voltage between the ground electrode and the tip reaches a high enough point that it arc through the air gap. If your tip shape changes or your air gap widen, your plugs need more voltage to arc.
You can always adjust the gap to change the amount of voltage requires to fire/arc. If you use Iridium or Platinum, the gap grow slower than copper/steel. The higher melting point of Iridium and Platinum also means you can use a narrower tip and/or increase the gap for the same voltage, or reduce the required voltage when all else remains the same.
You can use whatever plugs of the right heat range you want if you experiment the gap and find what works best for you, for the right interval.
What I don't know is, if you keep gaping steel/copper plugs, can you use it for more than 30k miles?
You can always adjust the gap to change the amount of voltage requires to fire/arc. If you use Iridium or Platinum, the gap grow slower than copper/steel. The higher melting point of Iridium and Platinum also means you can use a narrower tip and/or increase the gap for the same voltage, or reduce the required voltage when all else remains the same.
You can use whatever plugs of the right heat range you want if you experiment the gap and find what works best for you, for the right interval.
What I don't know is, if you keep gaping steel/copper plugs, can you use it for more than 30k miles?
What Panda Bear is very true.
A tiny air gap increase [under compression in the CC] has WAY more resistance than the difference between iridium and platinum tips.
A tiny air gap increase [under compression in the CC] has WAY more resistance than the difference between iridium and platinum tips.
Originally Posted By: mechtech2
What Panda Bear is very true.
A tiny air gap increase [under compression in the CC] has WAY more resistance than the difference between iridium and platinum tips.
I learned this with the turbo car. Stock ignition at the hp in my sig with 29psi boost wouldn't fire at all at the stock gap. Closed it down considerably to .020 and it worked fine.
What Panda Bear is very true.
A tiny air gap increase [under compression in the CC] has WAY more resistance than the difference between iridium and platinum tips.
I learned this with the turbo car. Stock ignition at the hp in my sig with 29psi boost wouldn't fire at all at the stock gap. Closed it down considerably to .020 and it worked fine.
Originally Posted By: mechtech2
What Panda Bear is very true.
A tiny air gap increase [under compression in the CC] has WAY more resistance than the difference between iridium and platinum tips.
Where did the "don't change plug materials" myth come from? It gets repeated almost as much as Pennzoil's sludge.
What Panda Bear is very true.
A tiny air gap increase [under compression in the CC] has WAY more resistance than the difference between iridium and platinum tips.
Where did the "don't change plug materials" myth come from? It gets repeated almost as much as Pennzoil's sludge.
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