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[CVO2FIXUP]

  I bought these super duper SE platinum, Iridium, gold plated diamond studded plugs thinking they are the sh-t. My builder tells me to go to the basic copper core cheapose.  Said they will make more power and have a hotter spark!!! Does he have a point? Do the standard cheap plugs work better even though the don't last as long?

[Ghost__Rider]

Nope..........But you'll get lots of sales pitches.........Stick with a regular ole platinum plug and save your money.

[glens]

Stick with whatever plug has the same electrical characteristics while being bathed in combustion following the spark event as has the stock plug if you want your Delphi Ion Sense combustion monitoring to work as intended.

[grc]

If you plan to go racing for real, then I suppose some super duper coils and plugs might be worth having.  Otherwise, stick with the stock stuff in your Harley.  The triple platinum super duper magic plugs and the super duper thick as your finger plug wires you see advertised are basically designed to relieve you of significant amounts of cash, not provide any real performance improvements.  And as noted by glens, if you stray too far from the stock electrical characteristics you can negatively affect how the Delphi Ion-Sense system works.  That system acts as a knock sensor using the spark plug and wire as the sensor.

Platinum or Iridium have an advantage over the standard plug in terms of longer life, due to the fact that those materials erode much slower so the electrode edges remain sharper and the voltage requirement to fire the plug remains lower over time.  So if you are the type to install a set of plugs and then never touch them for the next 50k miles, platinum or iridium will be of benefit.  If you change plugs at 5k or 10k like most Harley owners, you're just wasting the extra money for the high priced stuff.


Jerry 

[FLTRI]

Stock sparkplugs work great! Never found power, or anything else but expense, from performance plugs.
HTH,
Bob

[biganvil]

computer works best with the 6R12 plugs, they just selling you a high dollar plug for profits

[Ed Ramberger - One_Screamin_Eagle]

  I bought these super duper SE platinum, Iridium, gold plated diamond studded plugs thinking they are the sh-t. My builder tells me to go to the basic copper core cheapose.  Said they will make more power and have a hotter spark!!! Does he have a point? Do the standard cheap plugs work better even though the don't last as long?

I've personally tested all kinds of spark plugs on back to back dyno runs maintaining same fuel, engine temp, tire temp, room temp etc etc. and this is what I can tell you I have found.  The stock 6R12 plugs work great and I would recommend leaving them in unless compression ratio dictates a cooler plug.  The computer works in harmony with that plug, and I also believe the bikes run better with that plug - even over the H-D platinum plugs. 

[HILLSIDECYCLE.COM]

Biggest thing we've found is to gap them @ .035" on engines that carry north of 180 psi cranking.
BTW, we've used NGK's here for almost 2 decades now. DCPR8E's, in the T/C's, and BR5ES-11's for the Evo folks.
Scott

[HD Street Performance]

Run stock plugs 6R12
Got high compression run colder V-Rod plugs, 10R12 at .035

[lilcoot]

"I bought these super duper SE platinum, Iridium, gold plated diamond studded plugs thinking they are the sh-t. My builder tells me to go to the basic copper core cheapose.  Said they will make more power and have a hotter spark!!! Does he have a point? Do the standard cheap plugs work better even though the don't last as long?"

Don't waste your money.  I've tried iridium plugs before, they don't do anything better than regular plugs.  Starting, gas mileage, power are not improved at all.

[Talon]

with any new plug installed in your bike I don't think you'll see any major benefit between any of the top manufactures. The Iridium and some of the other special plated electrode plugs will help prevent long term wear, so if you leave our plugs in for 30-40K you might see a benefit with some of these plugs. Many on this site and change once or twice a year so you'll get no benefit from these plugs. The best spark comes from a sharp edge as plugs fire the edge of the electrode wears away and the edge is no longer sharp and this is when you spark starts to diminish. As for all those super duper add 20% more HP or MPH, if their clams were true every new vehicle to come out would have them from the factory. So IMO any quality plugs would be fine.

Craig

[dlaws01]

A spark is a spark. I wish someone would explain to me how any source of ignition to the fuel/air mixture can cause it to burn differently and cause more power.  I guess I'm just an idiot!   

[spydglide]

A spark is a spark. I wish someone would explain to me how any source of ignition to the fuel/air mixture can cause it to burn differently and cause more power.  I guess I'm just an idiot!   

Hey. . . don't be so hard on yourself.  They've been selling 'special' sparkplugs for many, many years.  I remember them as a kid (that's a long time ago).  har.  spyder

[MadCVORG]

No sense in putting out the big bucks if you stay on top of your routine maintenance. But if you bump up the compression, it's wise to run a colder plug to help dissipate the heat.

[TexasBowhunter]

Run stock plugs 6R12
Got high compression run colder V-Rod plugs, 10R12 at .035

Don
So what would you consider high compression before you change them to 10R12's
How about a 120R what's your recommendation stock or something a bit cooler
paul