Plug indexing

[Ghoste]

Just put new plugs back into my car and as I have for a long time now, I indexed all of my plugs.   It's something I'll likely always do anyway because it doesn't cost me anything but time but I never hear much about it anymore.  Is it something that no one else bothers with, an urban legend type of thing to do or is it generally accepted that it be done so it isn't worth mentioning?

[elacruze]

I index the stuff I really want right, like motorcycles and the Charger but I don't bother in my daily driver stuff.
I was surprised to find that dual ground strap plugs made a significant difference on the dyno (883 Sportster) and I expect it may be noticeable to index plugs for the same reason-better mixture access to the spark. The most noticeable difference was that the XL was much less sensitive to jetting with the dual strap plugs.

[68X426]

My impression (no survey) is that no one does it anymore except racers. My Hemi plugs have the cut back electrode so I don't see any value to indexing. I haven't bothered with my other cars.

Here's what Champion puts on their web site:

"Used by racing tuners only, indexing refers to a process whereby auxiliary washers of varying thickness are placed under the spark plug's shoulder so that when the spark plug is tightened, the gap will point in the desired direction. However, without running an engine on a dyno, it is impossible to gauge which type of indexing works best in your engine. While some engines may respond to the spark plug's gap open to the intake valve(s), others may make more power with the gap pointed toward the exhaust valve(s).
In any case, engines with indexed spark plugs will typically make only a few more horsepower at best, typically less than 1% of total engine output. While there are exceptions, the bottom line is that without a dyno, gauging success will be difficult."

So it worth it? 

[Ghoste]

Hmmm, I suppose in my particular case if it keeps me in the garage an extra 45 minutes tonight then it will mean an extra 45 minutes that I'm out of the littel bride's way.  That in turn will possibly buy me an extra 45 minutes of her being in a good mood so yeah, it's worth it.
Although I'm pretty sure those are results that Champion never tested for. 

[AirborneSilva]

Hmmm, I suppose in my particular case if it keeps me in the garage an extra 45 minutes tonight then it will mean an extra 45 minutes that I'm out of the littel bride's way.  That in turn will possibly buy me an extra 45 minutes of her being in a good mood so yeah, it's worth it.
Although I'm pretty sure those are results that Champion never tested for. 

I think that is called the serenity index 

[HPP]

Tried it in my bracket cars, never noticed in any increase in mph figures. Honestly, if it adds or detracts from power, it is so minor that variations in air density and driver inconsistency  are bigger factors to consider.

[1charger69]

this term "indexing" is new to me..can someone explain it and why we should or should not do it ...thanks

[HPP]

When you install the plugs, you add/subtract washers to the plug to move/rotate the location of the ground strap in the combustion chamber. The though being if you put the ground strap facing the chamber, that the open flame kernal from the plug will allow the ignition process to be exposed to the compressed mixture on top of hte piston and it will allow the flame to burn the mixture better.

[Ghoste]

In addition to that, what I had been told once by one of those old Stokc Eliminator guys was that it was also a part of trying to make everything in each cylinder as identical as possible in order that each cylinder produces the same power at the same moment in it's event cycle.  Supposedly to make a smooth even powerband. 
I'm still going to just stick with the keeping out of the way of the wife.