copper or iridium

sweetlou69

Member
:
2003.5 MSP
ive got the ngk copper plugs that are a step colder.. im just wondering if the iridium plugs are better? i know they run better and last longer but i was wondering if they are the same step of coldness as the coppers?
 
They run like crap and are terrible for putting into your turbo motor... Don't use Iridium or Platinum, or any other fine wire plug...

Reasons being.... that the finer wires tend to foul out sooner.. once they foul they are never quite the same... and you'll have nothing but issues.

The fine wire also lends itself to the chance of building up a hot spot much sooner... while fine in a lot of NA motors, it's not a good thing in a turbo motor..

Lastly, they cost a ridiculous amount, and are more likely to cause problems than to help... so without a doubt stick to plain old NGK plugs.. and personally I stick to the BKR series only.

Later!

Steve
 
Well, I have a different story!! I've had Iridiums for a year (I never bosted above 8 psi) and they worked very nice indeed. No fouling whatsoever. Borderline too cold at 5 psi (stock for me) but just perfect at 7-8 psi. I'm now using the Bosch +2 platinums and I like them even better. Again, no fouling.
 
FlyinMSP said:
Well, I have a different story!! I've had Iridiums for a year (I never bosted above 8 psi) and they worked very nice indeed. No fouling whatsoever. Borderline too cold at 5 psi (stock for me) but just perfect at 7-8 psi. I'm now using the Bosch +2 platinums and I like them even better. Again, no fouling.

They are fine until they foul... in a stock motor they likelihood of them fouling is pretty low... but can happen.. and once a plug is fouled once it is never quite the same... Regardless of the claims made, there is no noticeable difference with using them so then my question is always why spend the extra money? A set of BKR6E plugs runs you about 2.10 a plug... and you'll get equivalent or better (in the case of resistance to fouling) from them. The thing is that until you experience fouled plugs... and how much of a nightmare that becomes (it can be hard to diagnose in some cases), you don't realize how much of an issue that is. If you put an EMS on of any sort at any point you'll find out very rapidly just how difficult they become... :)

But anyway... is there anything wrong with them in a stock motor... no... but they are most certainly NOT worth the money :).
 
I agree with turf,turbo's need copper.not to mention you get a better fire out of a copper plug,they just don't last as long.

but I don't agree with the BKR series,I have noticed they have a higher fireing line,but lessburn time.
I prefer the ZFR's

I got no problem paying the extra $10 for new plugs whenever I change my oil.
 
livelyjay said:
Copper all the way.

Turf, why BKR6E and not BKR7E? What should they be gapped to?

From hot to cold it goes 5, 6, 7... higher number is a "colder" plug... if you run up to about 10 or 12 psi.. the 6 is fine.. NA only for 5's, and above 12 psi run the 7's.... The colder you go the better the chance of carbon or oil fouling... that is the reason to stay as hot as you can...

I gap at about 29 thousandths... you can go down to about 22 thou if you want for high boost pressures... usually our packs can't handle above 35 thou and keep spark under boost...

As far as the ZFR's.... the reason I stay away from them is two fold... the essentially advance your spark timing by 5-10 degrees because of the change in position of the flame front. By moving it closer to the piston crown it reaches it sooner... which is the same effect of advancing timing... it can lead to the flame front crashing into the top of the piston pre-maturely which is NOT ideal by any stretch of the imagination. Additionally, by being extended more they pick up more heat even at a colder range (a BKR6 is NOT the same heat range as a ZFR6... the ZFR6 will perform heat range wise closer to that of a BKR5). Almost any race motor building manual you pick up will discourage both fine wire and extended reach plugs.... extended are good for warm up if you have a stubborn starting car, but then pre-race they say to switch to a cold standard plug, or if you can go to a retracted gap plug that is that much better.
 
This is the first time I hear that Iridiums plugs foul on the MSP! I know a lot of people using them and they all report the same that I've experienced, and I've used them a full year (dunno)
 
FlyinMSP said:
This is the first time I hear that Iridiums plugs foul on the MSP! I know a lot of people using them and they all report the same that I've experienced, and I've used them a full year (dunno)

You misunderstand me a bit... My point is that a fine wire plug (platinum or Iridium) WILL foul easier than a copper plug by a long shot. Will it foul in your MSP... if everything is in good working order they should not. If anything goes wrong and AFR's get out of hand, or the turbo starts blowing by and you get oil in the combustion chambers etc... the plugs will crap out very very quickly. And it will cost far many times more to replace... If you run a standalone EMS and you don't get your AFR's and startup perfect on the first try or so forth... you will foul the plugs out immediately.. but coppers will hang in there a lot longer through bad conditions... and in the end regardless, there is no performance gain if gapped properly in the first place, and there is a heightened risk for detonation from the fine tip.... thus it would be to me a no-brainer to stay away from the fine wires.
 
If you wet foul it with gasoline it will clean up with a hard run... but anything else will not go away... carbon deposits can actually heat up and become hot spots and cause pre-ignition... and oil fouling is very hard to get off and usually the harder you go the more fouling of that nature that is likely to occur... so in short... odds are not good that hard running will help at all.
 
turf,if you take a look at they ZFR's reach they are extended compared to the BKR's,but they still don't hang into the combustion chamber for s***,I feel the BKR are under the lengh they need to be.

but I fully agree with your reasoning to use the BKR's.
 
don't mean to stall this thread, but Turf are you speaking of the BKR6ES-11. I've had these on my desk for like a year but I wasn't sure if it was compatible with my speed. Stockish boost btw. And I didn't want to start another thread. Sorry, back to topic
 
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I have used both iridiums in bkr7 and zfr6. ZFR6 is better for mild bolt ons. 12 or less psi daily driving. BKR7 for higher boost 12+ psi. Iridiums run great on all of the DFW MSPs that have them installed. Mazdaspeed75 checks his regularly and he can say they work great as well.
 
thanks JDM sam,I havn't run my car over 10 PSI yet.

I will still run the ZFR's when I put my motor backin,put once I break it in,I will most likely give the BKR's a try
 
The JandS showed a difference between them in my car for more detonation to show up on the ZFR's... so one of the reasons I shy away since my detonation detection system showed more activity with the extended reach plugs (Z-series) than without.
 
The Z series did start and idle better when I had them though... I do admit that... but too concerning for higher level applications.
 

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