Ngk irridium plugs

[PoorUB]

The stock spark plugs on the EFI bikes run a long time too. I ran the last set to 45,000 miles, but they were definately showing wear. I run the stock plugs two years, or about 30,000 miles.

[98fxstc]

Denso makes a better Iridium than NGK.

Any more info ?

Try this... http://www.globaldenso.com/en/products/aftermarket/plug/index.html

I'll have a look at that
Thanks

[FSG]

For the price of Denso Plugs I'll stay with the NGK, if they were for track use then yes, Denso.

[Phu Cat]

Denso makes a better Iridium than NGK.

Ya just gotta ask yourself:  "What is it that's better about the Denso than the NGK"?  If there is something, wouldn't the other plug companies want to get up to speed?

PC

[Nowhereman]

They have certain patents on Iridium application.
Extremely small electrode design among others.
All I know is that you can feel the difference at start up, cold or hot.
Small amount of money to pay for no worries.
I used both and stayed with Denso.
NGKs are not bad at all and I would use em if Denso's were not available.

[turboprop]

This would be really cool to have someone like stroker do a few spark plug comparisons on his dyno. Cut through some of this urban legend fluff. Maybe three runs, stock plugs, Denso plugs and a set of NGK plugs. Heck, if Jims up to it, I would even provide the plugs and ship them to him. Put this to bed, just like he did with the RB Racing pipe hype.

[Nowhereman]

I'm not sure what it would prove except a certain thing worked better on someone's Dyno.
I believe Dynos are good but, only as good as the operator who mans it.

[Phu Cat]

One thing's for sure: Electrode size aside, the spark is gonna jump from wherever it finds the least resistance.  Period. 

PC

[turboprop]

I'm not sure what it would prove except a certain thing worked better on someone's Dyno.
I believe Dynos are good but, only as good as the operator who mans it.

So you dont think that a dyno is able to show gain/loss in a direct A-B comparison conducted within minutes of each other? Really?

How would you quantify a claim of a spark plug being beneficial vs a different spark plug?

[Ohio HD]

Iridium plugs have their place and benefit. I have trouble even considering that you could feel, much less measure an improvement on most any street Harley motors. Now bikes with 13:1 and higher compression, spinning at 10,000+ RPM, yes, there would be a difference in how the motor performs.

My Two Cents On It.

[jam65]

Would anyone want to have their plugs yanked out of the heads at normal running temps. to make a case for this? I was under the impression that you do not want to remove spark plugs from a hot engine.

[Nowhereman]

I'm not sure what it would prove except a certain thing worked better on someone's Dyno.
I believe Dynos are good but, only as good as the operator who mans it.

So you dont think that a dyno is able to show gain/loss in a direct A-B comparison conducted within minutes of each other? Really?

How would you quantify a claim of a spark plug being beneficial vs a different spark plug?

Mileage for one.
Starting ease, idle, performance over different air temps, wear rate.
I'm not saying to not do it, I just don't know what we will see.
If you have someone who will willing to give up the Dyno time, by all means have fun.

[kong]

You tube video shows 3 horse power difference. Just sayin

[turboprop]

You tube video shows 3 horse power difference. Just sayin

Do you think three horsepower is within the accuracy of a DynoJet chassis dyno?

[turboprop]

This has already been discussed in depth countless times. Do a search on this forum for Denso or iridium.

[redmtrckl]

The only reason I can see to run Iridium plugs is they last longer. These cam out of my 2005 HemiKiller Chevy silverado Gen III 5.3 LS today. They have 146,880 miles on them and could have went another 100K from the looks. Each one still gapped .040.  I promise they make no more HP than standard plugs or platinum plugs. Same with my bikes. I always use OEM plugs where possible on these injected motors

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[mkd]

i run the plugs no more than 10,000 miles! usually less than that and it's about a season or two of riding for me. by changing them routinely every other oil change or so i can keep them from becoming hard to get out. the back plug binds a bit and has a tendency to be tight most of the way out
.

[redmtrckl]

I agree that changing plugs often is not a deal breaker.
They don't really cost that much and the piece of mind is worth those few $$.
It is after all and for the time being an air cooled motor.

[Ohio HD]

The only reason I can see to run Iridium plugs is they last longer. These cam out of my 2005 HemiKiller Chevy silverado Gen III 5.3 LS today. They have 146,880 miles on them and could have went another 100K from the looks. Each one still gapped .040.  I promise they make no more HP than standard plugs or platinum plugs. Same with my bikes. I always use OEM plugs where possible on these injected motors

[attach=0]

      My 2006 all aluminum HO 5.3L Silverado has 89,000+ miles on original plugs, was thinking I should change them, but it runs perfect and gets the same fuel mileage as it did on day one.

[boooby1744]

I thought running anything her than stock would throw codes?

[YFOPOS1]

How about Indexing the plugs    

Run Iridium plugs and Index them will get you a 6HP and 5Tq  gain !
I read it on the internet so it must be true     

[turboprop]

I dont understand the issue guys make about life expectancy of plugs for a harley. Does it really matter? It not like the plugs are hidden, hard to get to a a pain int he but to change. They can be changed in a few minutes with a cresent wrench if needed. Maybe there is more to it that I am not seeing, but to hear guys with a $15k+ motorcycle try and make a point about how long plugs last, who cares, even the higher priced plugs are inexpensive. Guys still looking for the magic spark and the debates on them reminds me of the old 'Taste Great vs Less Filling' commercials.

[truck]

I dont understand the issue guys make about life expectancy of plugs for a harley. Does it really matter? It not like the plugs are hidden, hard to get to a a pain int he but to change. They can be changed in a few minutes with a cresent wrench if needed. Maybe there is more to it that I am not seeing, but to hear guys with a $15k+ motorcycle try and make a point about how long plugs last, who cares, even the higher priced plugs are inexpensive. Guys still looking for the magic spark and the debates on them reminds me of the old 'Taste Great vs Less Filling' commercials.

[gordonr]

Back in the day when distributors were the main stay I had bought several engine analyzers over those years and always picked up problems on the secondary patterns due a plug that wasn't designed that particular ignition system. When iridiums first hit the market I saw secondary voltages drop and caused problems for the avail KV delivery. Most Iridium equipped vehicles have ignition systems that put out way more KVs than the HD system as per there design. I find if you study performance plug modifications (for a standard plug) in focusing the energy to one small area like the Iridiums do you will see a better outcome.

[Phu Cat]

Visualize this:The milli-micro second the spark happens, the plug is out of the picture and the flame front continues to expand.  Now just how much effect can that plug really have?

Iridium sounds kind of like platnum, that it would be very expensive.  I remember the Platformer engineer telling me during the refinery shut down we'd regenerate the catalyst this shut down but next time it will be replaced as it cost a quarter of a million dollars per reactor to replace it (big money in the early 70's).  So you can see why there isn't much ( as in hardly any) platnum on platnum coated plug.  And I'm betting iridium plugs are the same. So, again, how much effect can there be?

PC