Iridium spark plugs
Outstanding HDF Member
Joined: Sep 2008
Posts: 2,408
Likes: 1
From: pottsville,pa
I agree, your not gonna see or feel any performance increase dyno wise or by seat of pants. Most people that change plugs/wires and notice their fuel mileage,throttle response is a little better is because it was time to change them, not because the new plugs are that much better. You would get the same effect if you threw in a fresh set of stock ones. As for stainless/platinum/iridium/copper/gold plugs, the higher quality of metal, the better it holds up to corroding/fouling, but thats about it.
Ultimate HDF Member
Joined: Oct 2007
Posts: 7,562
Likes: 11
From: Palm Harbor fl.
http://www.amsoil.com/news/2008_motorcycle_dyno.pdf
NGK do provide a small edge on the dyno... Won't feel it on the street necessarily. A shop I go to uses them for bikes they are running at horsepower shootouts. They know they add an edge over a standard plug on the dyno... They actually don't push the plugs necessarily for street use. They will say that the benefit to the plug is like the benefit of owning a dyson over say a hoover. The hoover may perform just as good initially but eventually will clog and not work to full effectiveness they way a dyson will... Anyway the plug works better longer, just don't buy it expecting any real performance boost that you could actually feel. If you do feel anything, the old plugs were bad or the it is placebo.
Anyways, someone said 'let's see the #s' so there they are... believe em or not.
NGK do provide a small edge on the dyno... Won't feel it on the street necessarily. A shop I go to uses them for bikes they are running at horsepower shootouts. They know they add an edge over a standard plug on the dyno... They actually don't push the plugs necessarily for street use. They will say that the benefit to the plug is like the benefit of owning a dyson over say a hoover. The hoover may perform just as good initially but eventually will clog and not work to full effectiveness they way a dyson will... Anyway the plug works better longer, just don't buy it expecting any real performance boost that you could actually feel. If you do feel anything, the old plugs were bad or the it is placebo.
Anyways, someone said 'let's see the #s' so there they are... believe em or not.
Last edited by rounder; Feb 4, 2010 at 01:56 PM.
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Road Captain
Joined: Oct 2009
Posts: 728
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From: So Cal
Might want to check this out http://www.youtube.com/watch?v=0A9_7RtFoZ4
Intermediate
Joined: Jul 2010
Posts: 30
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according to harley davidson you can use any harley branded plug and the anti-knock still works... thus screaming eagle iridiums still work with anti knock.
Source: I actually called HD and talked to an engine tech.
Source: I actually called HD and talked to an engine tech.
Supporter
Joined: Jan 2007
Posts: 15,788
Likes: 5,625
From: along the shore of Mishigami
Here's what I found last year in Thunder Press.You will have to do a little work.
Google Thunder Press
search for the 2009 issue and then scroll down to May
Scroll down to Motorhead Memo- "Elementary"
This article was written by Kip Woodring, A former service knows this aythor and he said he knew his ****. They've been in my 05 FXDLI for over a year. Easier starts, no pinging or codes. No problems, also using 1 heat range colder, no fouling.
Google Thunder Press
search for the 2009 issue and then scroll down to May
Scroll down to Motorhead Memo- "Elementary"
This article was written by Kip Woodring, A former service knows this aythor and he said he knew his ****. They've been in my 05 FXDLI for over a year. Easier starts, no pinging or codes. No problems, also using 1 heat range colder, no fouling.
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Joined: Aug 2010
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From: Saint Louis
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Intermediate
Joined: Jul 2010
Posts: 30
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Here's what I found last year in Thunder Press.You will have to do a little work.
Google Thunder Press
search for the 2009 issue and then scroll down to May
Scroll down to Motorhead Memo- "Elementary"
This article was written by Kip Woodring, A former service knows this aythor and he said he knew his ****. They've been in my 05 FXDLI for over a year. Easier starts, no pinging or codes. No problems, also using 1 heat range colder, no fouling.
Google Thunder Press
search for the 2009 issue and then scroll down to May
Scroll down to Motorhead Memo- "Elementary"
This article was written by Kip Woodring, A former service knows this aythor and he said he knew his ****. They've been in my 05 FXDLI for over a year. Easier starts, no pinging or codes. No problems, also using 1 heat range colder, no fouling.
http://www.thunderpress.net/MONTH_AR...headMemo.shtml
Road Warrior
Joined: Apr 2009
Posts: 1,360
Likes: 4
You must have put them on upside down, should have gotten at least 16HP... 17 on a red bike....