fittrjoe

so ive been doing my usual searches and im starting to see a pattern that copper is the preffered plug . currently running bosch platinums in my 90 s2 cab . can someone please explain, is it a money thing...or a performance issue. my car is street only but i push it hard @ times. if it is performance issue or better for motor ill switch them out in a heartbeat. just wanted to know if there is good science behind the debate. thanks rennlist

Rogue_Ant

Copper > platinum for performance/power.
Platinum > copper for longevity.

fittrjoe

ok , thats what i was thinking. thanks ill probably get coppers as longevity is not an issue.
nice splitter man, would you recomend it.?

misnblu

Since the statement was made, there needs to be an explanation as to why it was made.
My understanding is that the Platinum plugs have it easier to produce the spark while the coppers require more to produce the same spark so why is this recommended?
I'm no expert but I've been working on cars for 30 years now and have just about always used Platinum for the performance end of it.

Now in my case, I change my plugs every time I change my oil and longevity is never a concern for me in any of my cars that I own.
Overkill maybe but they're cheap enough to replace like any oil filter if you know what I mean.

KuHL 951

I'm no expert either but I do work with platinum products in many DC circuit designs. Copper is the second most conductive metal behind silver; platinum is even less conductive than iron and actually a poor conductor. The main benefit of platinum is longevity and it's low oxidation rate. It takes a much higher voltage to draw a spark from platinum or platinized niobium/titanium than copper in any given open arc environment.

Rogue_Ant

Kuhl 951 nailed it. Platinum sucks as a conductor compared to copper. The only benefit of platinum is that it is harder then copper, and thus lasts longer.

DHC6

Can any one honestly tell me they feel a difference? for the difference in cost vs benefit, I just go with the less expensive plugs and change them often. It we had cars where it was a huge pain to change, then I might consider longer lasting plugs, but since we only have 4 and they are easy to change, why not change them often and keep them fresh? I believe in paying for good parts, but the value has to be there, and in my experience I have never felt the difference between in-expensive plugs and expensive plugs. I can feel the difference between old and new, that's for sure.

misnblu

Thanks for the answers guys.
So physical size has no bearing on the spark, its ease, or how the spark is made through the tips to the ground?
And let's put Iridium into the question on this too as this seems to be the turbo's guys plug of choice over any other.
If I'm a pain, I'm sorry but curiosity has the best of me at the moment.

Oddjob

The primary issue with the bosch platinum plugs, especially on turbos and especially for track use - they blow the tips off. Relatively common problem, and known in the p-car community. Bosch Supers (copper) are the better plug to use, and cheaper and easier to find at the local store.

944Ross

The copper in plugs is inside the insulator and used to conduct heat away from the tip, allowing the tip to project further into the chamber without overheating. There are some ignition systems that can't tolerate platinum plugs. It is not necessarily an upgrade to go to platinum plugs, just like using high octane does not necessarily give an improvement in power.

ZR8ED

As already stated, if your car was not designed with them in mind, stay away from them. From years of experience, platinum plugs do not work as well in the old Datsun Z cars as well as the stock copper NGK's. Don't be fooled by advertising propaganda telling you they are a superior plug. Many new cars are designed to be used with these plugs, so they should continue to use them.

931guru

Copper good. Platinum are fine until they stop working, and the key difference is that you can't tell by looking at the tip.

running_cold924

copper, these cars will thanks you for it

misnblu

That's good to hear then on the plugs.
I've not yet pulled the plugs from my 944 to see what's in the head since I'm in need of doing a complete tuneup to the car and to know that everything is as it should.
Any recommendations on the plug for the 86 n/a 944 then?

And thanks for everyone's patience in answering this newbie 944 owners questions.