Anybody know anything about indexing spark plugs? Procedures? General Theory? I heard it adds horsepower across the band, but why? and how much? Thanks for your help guys

Indexing is lining up the plug gap with the electrode facing the exhaust valves. You use varying thicknesses of washers to enu up with all the plugs "facing" the same way. It keeps a consistant flame front and resists blowout from the intake charge. But, we use a multi-electrode plug that has no "front" or "back".

But I run triple ground plugs, so I'm not worried.

I was under the impression that the plug gaps were supposed to face the intake side! Now i have two different answers, and i am confused. I was going to index mine tonight. By the way, idon't own an audi, i own a nissan, so indexing does apply to me. Could it be that for some cars the plug gap faces exhaust and on others it faces the intake???!?!?!?!?<br>Sheesh

Face the gap to the intake valve side on a non-boosted engine.