Spark plugs can only be gapped so far from their original spec, otherwise the electrode angles are bad and your spark will be weak.

Bigger gaps actually make more power, but you need stronger and stronger ignition system to accomplish this. This doesn't mean you should all stretch your plugs out either.. .060 on factory spec plugs, and what'* mentioned in the techinfo for all other options.

If you have doubts as to plug gap specs, follow this:

Factory heat range plugs: .060"
One heat range colder: .055"
Two heat ranges colder: .045-.050" (depending on plug manufacturer).

If in doubt, call your plug manufacturer. That'* where I got all the NGK info in that article.

Let'* say you have high voltage aftermarket coils [like you do, Bill]. Then, you have some TR55'*.. and you gap them at .60. Would that be enough voltage to give an increase? My ignition was so weak, my plugs were gapped at .40, apparently the idiot mechanic thought smaller gap = easy fix for crappy ignition. Anyways.. I guess what I am asking, what would it take [as far as ignition power] to have a .60 gap on one heat range colder plugs?


-justin