So iridium, platinum and even silver , neither conduct as well as copper and copper sparkplugs have always produced a better spark. Buuuut they definitely don't last as long as the other precious metal sparkplugs. But who cares when you do routine maintenance and enjoy it.
have any of you run these plugs befor ? They are a step colder too.
i havent started the car or tested them YET because i need to replace my axle first ( tomorrow hopefully). So I will give my 1st hand feedback on them once I do.
i posted a pic of them next to the typical plugs we run , these theoretically should provide better power delivery because of copper aaaaand they have 2x less prongs so the spark shoooooould be more likely to fire 1x full discharge to the prong and not have the spark spread apart to other prongs. I know the prongs are there encase they get old and have another spot to fire on but I always wonder about their efficiency..
mods are :
ported facelift sc with 19% pulley , ported ic horns and ported throttlebody and intake , ported sneedspeed intake Manifold , xforce catless 421 headers and Milian exhaust , 380cc injectors , msd coil and wires and facelift ecu with factory GP tune

 

yes. I have used the iridium as well. I use the 8 heat range myself but they can not play nice 8's with factory dme. I have had issues with the iridium tips and e85/meth so i went to the stock multi design but in 8's. fwiw I dont have normal/stock dwell times/setup on my coil though.
But in regards to 8 heat range I have had noticeable issues with both stock dmes from time to time so when I had the stock dme I used 7's of either design. No idea why or a fluke thing or what. But unless your hammering on it at track or it makes some wild power 7's should be fine and those multi plugs would be fine. No idea on any other coil other than factory supplied unit.


oh wait looked at pic again. Nope never used a two prong plug on anything. Flat plugs on rotaries though lol Do they project further into chamber with that tip? Dont want that

 

no.. I was worried about that or the plug boots stick up but they're the exact same lengths thxfully.
according to ngk specs , they're both 19mm reach actually..

 

just measure the tip itself and if they differ. The over all plug or thread could be the same but the tip might not be. It could be a piston party pending on cam specs. It would be for me as I am so tight as it is 1.5mm clearance now from piston to full valve event. So if I got a plug that was that much protruded/extended from tip. Honestly just stick to what you have used and got tuned with. To risky for my blood/investment. I always worry about tips or porcelian breaking either from freak accident or something else as its happened to me and I got ***** lucky it shot exhasut valve without doing damage. Others not so lucky when that happens.

 

the tip length , after the threads with the prongs looks to be the same. The coppers plugs prongs don't go down as low but the electrode tip does as where with the 5x prong plugs the electrode is beneath the prong. But even then , they stick out the same length past the threads equally.. their vehicle fitment guides also list the same engine and vehicles also..
buuuuuuut to make sure for sure ,I will rotate the engine by hand juuuuuuust to make sure. But I'm 99.9% sure they're the same length/depth.
and this car wasn't custom tuned yet either. It's still on just the face-lift ecu with factory GP tune , id like to do few more mods before I have a custom tune done.
afr are still good yet. Could be a tad more rich bit it's definitely not unsafe lean.
and Im trying to get it running as well as it was , i sold a buddy some parts out of this engine to get his up n running again.. lol , his car even has my old stock cam from my other car but atleast his cars running again for him.
wish I could say the same.. too busy fixing other peeps stuff and pushing mine to the side.

 

And don't our plugs sit at the top of the combustion chamber and just the tips petrude into the cylinder head dish ? I'm almost positive they don't thread past that point and I'm almost posting there's a good 1/4in gap when the piston is at TDC.. unless the plugs hang down into the dish more than I remembered ???
best to turn it over by hand then juuuuuuuuust to be safe.

 

You might be surprised to learn that almost every spark plug has a built-in resistor. In fact, the "R" in the NGK part number stands for "resistor." This is done to reduce EMI emissions that may otherwise interfere with the car's electronics (and sometimes comes through as noise in the stereo). The resistance is surprisingly high, usually a few thousand ohms. The added resistance of a platinum or iridium electrode is less than 1 ohm, so using a copper plug instead doesn't yield any difference in performance.

You can get non-resistor plugs, but they're not common and you may not see a benefit since the ignition system was designed with resistor plugs in mind. In fact, it's likely to cause driveability issues.

 

The car ABSOLUTELY LOOOOOVES these sparkplugs. I just swapped out the plugs and fuelinjectors both of which had only a few 1000 miless on them but were about 6months old and HOOOOOOOOLLY CRAAAAAAP.
LOL tire frier in 1st gear , it has such better throttle response than it ever has. Lol it has better throttle response than even my fully built grey mini ! 🤣
it ALSO build 18.5psi SOLID instead of a semi solid 17psi and an occasional 18psi for very last rpm. Now it builds 18.5 when it used to hit 17 and just holds it..
awesome, just awesome..
Do I suggest these plugs to others with modded engines ? ABSOLUTELY !!!!!!