Iridium Spark plugs

you need to consider that the irridium plugs are resistor plugs--therefore---if you are using red plug extensions--go get some black ones to get the irridium plugs to opperate correctly.

 

Here are two interesting links that provide information concerning iridium, should anyone have the intellectual curiosity.

http://pearl1.lanl.gov/periodic/elements/77.html

http://encarta.msn.com/encyclopedia_761556286/Iridium.html

Jim S.

 

no need.
dyno proves not increase in power of iridum/pt plugs v. copper plugs (of the same temp range).
using the pt/iridium plugs is a matter of convinence and service life. they last longer,and therefore are more convinent, the nominal increase in power that you may experience could be negated by a change in ambient conditions; it's that small, in the real world.
in high compression applications, etc ( where the temps are higher) you should give the temp range of the plug more consideration , and the non-reactive materials may give you better protection in a higher temp environment (but you shouldn't be running hot anyway, if you've got your air/fuel ratio setup right -- otherwise you'll be rebuilding the motor b/c of detonation).
if your plugs are a pain in the ass to change frequently, then i can understand using the "exotic" plugs , but the hp advantage is marketing hype.

 

Charles (atlantaman), not necessarily. I have the stock red (oem) plug extenders on my 328, and when measured, they have no resistance....so not all red extenders have resistors in them. There was a thread on this in the old Chat website...

Dave

 

Iridium can initiate a spark easier because the electrode can be made smaller in diameter. This creats a larger electric field gradient, which is easier for a spark to jump.

Iridium can get away with a small diameter tip because it is so resistant to heat, acids, and other things that happen in the combustion chamber. A smaller tip heats up faster (starting), but does not initiate detonation because it is so small, and with its high specific heat does not 'feel' hot to the compressin mixture in the cyclinder chamber.

Note: you can put in 7 sets of NGK copper plugs for the cost of a single set of Iridiums (if you do your own work, and don't count the towing bill) So if you idea is 30K miles on one set of plugs, then Iridium is a decent choice. On the other hand, if you are changing plugs each year during winter maintanence, regular copper plugs are just fine.

 

I replaced the Champions with NGK Iridium plugs a few weeks back and my car has been fine since. I was having a problem with the extenders burning through before that so I just replaced everything. So far so good.

I am curious about the red extender vs. black extender comment. Do the different extenders really make a difference with Iridium plugs. My car has driven fine but if there is an advantage to having a different extender for these new plugs, I'd like to know. Thanks.

 

I replaced the champion plugs in my 348 Trubo with Denso Iridium plugs and solid silver core racing wires, no extenders. I was trying to cure a high boost miss. No difference at all. The Champion plugs Norwood had installed proved to give identical service with the factory wires in my case. FWIW......................

 

I've put them in my Ford F150. over $100.00 bucks. I like them and will put them in the Ferrari . I got some NGK platinum pugs in there now. When I start noticing a miss or 20,00 miles I will try the IR's.

kelly