Iridium Vs. Platinum Plugs

[negoshi8or]

Hey SAU peeps,

With my R33 getting it's 100k service - I changed the plugs myself to save some cash and learn something new.

BIG THANKS to members who posted tutorials for changing plugs - they were a great help.

Pulling the plugs out on the RB25DE they were some American brand... in a Jap car? (go figure...)

Anyway the plugs were in good condition - not covered in soot or oily. So the engine is running well.

After reading the forums I chose to install some NGK iridium’s (they were matched to the engine so no I didn’t stuff it up)

And after installing I found many problems with rough idle and acceleration - you could call it a gentle misfire or a "popping" sensation if you get my meaning.

On my mechanics advice I changed them to Nissan platinum’s and the misfire was almost gone - none under acceleration - just on idle - so infrequent that you almost cant notice it - but I am anal, so I did ;-) lol...

It turns out that one of the coil packs is on its way out - or beginning too. Replacements are coming soonest.

At the end of the day - using iridium plugs enhanced the problem of the coil packs. Using factory recommended platinum’s almost cured the problem.

So my experience is to stick with platinums.

Edited June 14, 2007 by negoshi8or

[superspit]

Hi..

That is odd!!!

I love my NGK Iridiums !!!!!...

But then again, I set them up properly...hehehe!

I will not be using anything else in future, especially those majorly over-priced Nissan Plat's. (they are good though!!)

Anyways, glad you're happy now...

Regards,

[mid life crisis]

personally i have less problems with plain copper plugs shit load cheaper as well

[SECURITY]

your problem isnt with the type of plug suited to the car, the problem is the gap they come with. larger gaps will cause a bit of a miss under load. smaller gaps wont.

if you know how to re-gap spark plugs i recommend gapping your iridiums to .8mm using a feeler gauge and trying them that way. if it still doesnt work then at least youve still got your platinums.

[grandmasterb]

personally i have less problems with plain copper plugs shit load cheaper as well

Yeah cant go wrong $10 for a set of copper plugs.

your problem isnt with the type of plug suited to the car, the problem is the gap they come with. larger gaps will cause a bit of a miss under load. smaller gaps wont.

if you know how to re-gap spark plugs i recommend gapping your iridiums to .8mm using a feeler gauge and trying them that way. if it still doesnt work then at least youve still got your platinums.

As stated above it sounds more like that gap (which probably would of been 1.1) with your miss problems, get the feeler gauge out and re gap them and see what happens like Joe said you still have the other plugs if nothing changes

[superspit]

personally i have less problems with plain copper plugs shit load cheaper as well

I just don't understand this comment......or the others like it.

How could you have less problems using an inferior copper plug?

I understand the price point makes them attractive, but why would you want something that requires changing so often (or have them changed by an expensive mechanic!).

I think the cost thing is negated simply on that point.

Also, the wear and tear on removing covers, IC piping, leads, transformers etc could lead to an expensive job with constant removal and subsequent re-installation from using the shorter life copper plugs.....

...no, not for me....I'd rather be driving than servicing.

I also think that the majority of issues is to do with the 'purchaser' / 'installer' of spark plugs, they simply don't understand gap importance, go head on into a job without the research or they expect miracles from the plugs themselves, be it copper or plat/iridium...ie...noobs.

Anyways, just thought I'd throw that into this 3 ring circus ..... :laughing-smiley-014:

Kindest Regards,

Superspit.

[SECURITY]

copper is actually a better conductor than the iridium or platinum coated plugs. ontop of that they cost next to nothing compared to iridiums or platinums.

and not everybody pays a mechanic when getting something done. iridiums may be good for you, but the obvious choice for everyone in the know.

[superspit]

copper is actually a better conductor than the iridium or platinum coated plugs. ontop of that they cost next to nothing compared to iridiums or platinums.

and not everybody pays a mechanic when getting something done. iridiums may be good for you, but the obvious choice for everyone in the know.

Thankyou Security...but this looks to be unconvincing to me...sorry...did you really read my thread, which I thought was quite objective in parts?

could someone please tell me why I should go to coppers...or, could someone else give a reason why one should stay with the factory specified plugs.....ps.not interested in cost, I'm more interested in standard skyline performance. (ie.not racing).

I'm really looking for some fresh responses here, and think that many others may be interested in this age old topic.

Kindest Regards,

Superspit.

[Mr. Oizo]

In a "performance" engine, the increased temperatures and pressures of the combustion chamber can break the fragile tip off the Iridium plugs.

Not only that, but Platinum is a catalyst for heat... which leads to pre-ignition...

Copper has proven itself time and time again.

Unless it's in an NA grocery getter, stay away from Platinum Plugs

Here's an excerpt from Sport Compact Car magazine

"Take an ultra-high output turbocharged engine for example. to operate safely at a high boost the engine requires colder plugs. these cold plugs don't reach sel-cleaning temeperature off-boost, however, so the plugs foul and the engine tends to run poorly whenever you aren't abusing it. the self-cleaning properties of the surface gap design should help preventmisfires under these conditions, correcting the engines masochistic split personality. at the other end of that engine's boost curve the surface gap design could again prove useful. as air pressure and fuel density increase in the plug gap, (both of which happen when you turn up the boost) the voltage required to initiate a spark increases, often to the point where even a strong ignition system can't consistently provide enough voltage. in this case the reduced voltage requirements of the surface gap could keep the engine running properly at high boost, making more power, and possibly allowing a higher boost limit.

of course all this is speculation. currently the coldest platinum +4 plugs have a 7 heat range, and no applications have been releasd for turbocharged vehicles. Trachte explains that applications were being released in stages. those for which there was little doubt that the plus would work, and where a minimum of testing would have to be done, have already been released. those applications where there was some possibility of a problem, such as turbocharged cars, are undergoing further testing and evaluation before the plugs are released. in teh case of turbos, trachte is concerned that the increased combustion temperature combined with the soark rcing across the surface of the insulator could overheat the insulator. this could make it more susceptible to pucnture failures when sparks try to jump through the insulator from the center electrode to the shell of the spark plug. remember though that he is looking for 100,000 mile reliability. nobody running the kind of boost that would require a colder plug or a stronger ignition system should haev any illusions about keeping their spark plugs nearly that long. overheating the insulator may not be a problem at all, but only further testing will tell.

one place the platinum +4 won't help is a rotary. while the multi electrode design is similar to many of the most effective rotary plugs, martin kasnowski, product manager for aftermarket parts, warned that their tests had shown a sttrange vibration peculiar to rotaries could occasionally cause the ground electrodes to break off. since demand for rotary plugs is low bosch didn't bother to solve the problem. with only that one caveat, though, the platinum +4 appears to be as close to a miracle cure-all spark plug that you're likely to find. ................"

[RBwhatever]

your problem isnt with the type of plug suited to the car, the problem is the gap they come with. larger gaps will cause a bit of a miss under load. smaller gaps wont.

if you know how to re-gap spark plugs i recommend gapping your iridiums to .8mm using a feeler gauge and trying them that way. if it still doesnt work then at least youve still got your platinums.

You shouldn't re-gap iridium or platinum plugs yourself. They are actually iridium or platinum coated, not solid iridium or platinum.

If you re-gap these plugs you take off or chip some of the iridium or platinum coating thus reducing the life of the plug severely.

If you want a certain gap with these plugs they should be bought pre-gapped.

The reason you can re-gap copper plugs to your hearts content is because they're solid copper, no coatings.

Thankyou Security...but this looks to be unconvincing to me...sorry...did you really read my thread, which I thought was quite objective in parts?

could someone please tell me why I should go to coppers...or, could someone else give a reason why one should stay with the factory specified plugs.....ps.not interested in cost, I'm more interested in standard skyline performance. (ie.not racing).

I'm really looking for some fresh responses here, and think that many others may be interested in this age old topic.

Kindest Regards,

Superspit.

I'm going to go against the grain here and agree with superspit. I'd rather not be changing my plugs every 5000kms.

I've replaced my plugs with Iridiums and could not be happier.

I even used the factory specs for the plugs which is 1.1mm gap and heat range 5 (oh no! he used heat range 5 and a 1.1mm gap, that's a sin!).

I have all the stage 1 mods on my car, exhaust, 12psi, Pfc, fmic, blah, blah blah and I have not experienced the misfiring that everyone complains about. To add I also have a 93 R33 and still have the stock coilpacks. And yet you'd think I'd definitely have a problem because they're so old.

I hate it when someone says "you should always gap your plugs down to .8mm and use a colder plug" when its totally not necessary.

In my personal opinion, use the factory specs for your plugs. If you experience problems, then use plugs with a .8mm gap and colder heat range, and copper if you must.

But for those with regular track visits, I can understand using .8mm gaps colder heat range and copper. But if you don't visit the track, why should you? If you don't have problems with the factory spec plugs, why change it? (rhetorical question)

Cheers

Edited June 19, 2007 by KeyMaker

[superspit]

The reason you can re-gap copper plugs to your hearts content is because they're solid copper, no coatings.

I going to go against the grain here and agree with superspit. I'd rather not be changing my plugs every 5000kms.

I've replaced my plugs with Iridiums and could not be happier.

I even used the factory specs for the plugs which is 1.1mm gap and heat range 5 (oh no! he used heat range 5 and a 1.1mm gap, that's a sin!).

sounds good Keymaker...I thankyou for that.

regards,

Superspit.

Edited June 18, 2007 by superspit

[nsm034]

i replaced mine with iridum .8 . on recommendations by tuner i swapped to .8 coppers and found it actualy ran smoother, go figure

[superspit]

i replaced mine with iridum .8 . on recommendations by tuner i swapped to .8 coppers and found it actualy ran smoother, go figure

hi NSM...

maybe your other plugs weren't screwed in properly???

Seriously...all this talk on coppers has made me decide on something....

I have some time off very shortly, so I'm going to humour myself, go and spend 10 buck on some coppers, chuck'em in the line, push it real good, and see what happens.

I'll get back to you guys with a report of my own personal findings..

regards,

Spit.

[arbess]

Well heres my fat 2c

For your thread: Platinum or Iridium, I use Iridium, always have in my GTR and GTST. I find it really good and not had one issue with them. THERE IS MY ANSWER TO YOUR THREAD.

Now for some extra info. The GTR's came out of the factory with platinums. Now Nissan wouldnt make a car to detonate using platinum plugs, in fact they would tune it to provide maximum safety and maximum power... so this talk on pre-igniting fuel is some weird talk.

When I was experimenting with copper in my GTST, I found that it was great for 1000km after that, ran like a pig.

Also the less and less you change your plugs the less wear you are putting on your engine parts, as in on-off-on-off etc etc. More screwing around, you'll end up breaking something.

Gapping, buy the freaking right gapped plugs in the first place, and yes try a hotter heat range as in a 5 if your car is running crap.

My true answer to this is, buy the factory spec plug because its already been engineered for you. you should not have a problem using a recommended platinum/iridium plug, in fact why dont you email NGK to see what they list for your car.

b!tching closed.

[superspit]

Well heres my fat 2c

For your thread: Platinum or Iridium, I use Iridium, always have in my GTR and GTST. I find it really good and not had one issue with them. THERE IS MY ANSWER TO YOUR THREAD.

Now for some extra info. The GTR's came out of the factory with platinums. Now Nissan wouldnt make a car to detonate using platinum plugs, in fact they would tune it to provide maximum safety and maximum power... so this talk on pre-igniting fuel is some weird talk.

When I was experimenting with copper in my GTST, I found that it was great for 1000km after that, ran like a pig.

Also the less and less you change your plugs the less wear you are putting on your engine parts, as in on-off-on-off etc etc. More screwing around, you'll end up breaking something.

Gapping, buy the freaking right gapped plugs in the first place, and yes try a hotter heat range as in a 5 if your car is running crap.

My true answer to this is, buy the factory spec plug because its already been engineered for you. you should not have a problem using a recommended platinum/iridium plug, in fact why dont you email NGK to see what they list for your car.

b!tching closed.

well, ........I guess that's that!!

hehehehe...... :laughing-smiley-014:

[arbess]

To chuck a spanner in the works,

im looking at getting some Iridium IX shortly, hopefully they will have a smaller gapping to try. They state they use less voltage to create the spark, in which my understanding from physics year 12, will have less heat generated around the coil packs.

Edited June 19, 2007 by arbess

[SilverECR33]

Yea, Ive been using Iridiums and they are great. last for ages. no missing or anything, also noticed smoother idle, crisper power delivery and better fuel economey. runs like a dream all the time. sure they are more pricey but as they say "you get what you pay for".

ps. arbess id be interested to know how the new Iridium IX's go

[govich]

so this talk on pre-igniting fuel is some weird talk.

This would be true if all the cars we're talking about were as Nissan released them from factory. Copper is probably the best thermal conductor you will find, and Iridium/Platinum plugs will tend to retain heat near the tip which could lead to pre-ignition under extreme conditions.

Just FYI, i run NGK BKR6E-11 copper plugs at 1.1mm gap (with Splitfire coils) at 0.85bar boost pressure in an RB25 and haven't had a hint of misfire in the few months it has been this way.

edit: Just to add to this, i'm not necessarily saying Iridium/Platinum plugs are bad. The advantage with these materials is in their relatively high strength, higher melting point etc, which means the tips can be made finer and you then don't need as much voltage to create spark, and also that they will erode more slowly, leading to the much longer service life. Technically you should be able to run a larger gap with Iridium plugs, and you'll see some OEMs recommend using larger gaps with these. If you look at NGK's racing spark plug catalogue, there's no copper plugs to be found anywhere. It's all about matching plug to application.

Edited June 19, 2007 by govich

[arbess]

Yea, Ive been using Iridiums and they are great. last for ages. no missing or anything, also noticed smoother idle, crisper power delivery and better fuel economey. runs like a dream all the time. sure they are more pricey but as they say "you get what you pay for".

ps. arbess id be interested to know how the new Iridium IX's go

hehe not a worry mate, will be looking at getting a set soon.

[Fixxxer]

Like I've said in other threads, my 32 GTST came with Iridiums and the car missfired like a beeatch, I never checked the gap on the Iri's though, so it may have been 1.1mm. I might try them again some day if I can get them in 0.8mm.

On the copper side: I replaced the iridiums with coppers (0.8mm) and it ran great, which solved my problems, and made me

I also find that I can get at least 10000 out of the coppers before I wish to change them (I could probably go further but just for piece of mind I change them). So, every 2nd service I do the plugs.

On another note, I may go to Iridiums because soon the coppers will be just as expensive.... seems every time I go to autobarn they have jacked up the price again, last time they charged me $5 per plug.....

Fixxxer