GenVibe - Community for Pontiac Vibe Enthusiasts

Do this to a new set of plugs. The earth electrode can be rather weak after the plug has been used, and it may "snap off" while you try to bend it into the proper position.Anyone care to guess how I know?For those of you who use "ordinary" plugs. Every 5,000 to 10,000 miles or so, yank your plugs and file down the sides, end, and bottom of the earth electrode with a small metal file. Just remove enough material to expose new metal, don't actually grind anything away. Ditto for the round positive electrode in the center. Just make sure you re-gap the plugs when done. Basically this process exposes "new" "fresh" metal for the spark to jump across. It's like having new plugs every 5,000 to 10,000 miles.Doing this didn't seem to help HP, but throttle response was better and gas mileage went up by about 2-3 MPG See how they've shaved the electrode down and now placed it off to the side? Gapping your plugs this way completely "opens up" the spark to face the combustion chamber, versus being "squeezed out" sideways. Flame front propogation times can improve by using this, as well as it can keep your plugs from fouling as fast.You can do this with any plug, just gotta spend some time grinding and filing and measuring Once you get good, it only takes about five minutes to do a set of four...The only real "performance" way to gap them is to use a die grinder and grind off the ground electrode (the L-shaped piece) and SIDE-gap the plug.Doing it this way, you gap the plug by adjusting the distance between the center electrode and the ground strap thingy on it's side.Another thing I have done that works great is instead of increasing the gap set by the maufacturer for the vehicle you should shorten it a little.Larger gap = Shorter duration spark. The spark is physically longer, but of a shorter duration.Smaller gap = Longer duration spark. The spark is physically shorter, but longer duration.The larger the gap, the more voltage it takes to bridge that gap, and the shorter the time the coil is capable of producing voltage sufficent to jump that gap. You also run the risk of "spark blow out", where the spark is of such a short duration, that the turbulence in the combustion chamber can actually "blow" the spark out before igition has a chance to start.If anything you would want to narrow the gap a tad, not enlarge it. I've found running .040" rather than .044" works best. I've tried as small as .030", and worked up till I got the best results. Of course, none of this was dyno tested, it was all based off fuel economy, feel, and "misfire.Any questions just ask me.

I've used the Bosch side gap plugs on two vehicles, a GMC V-8 and a Ranger 4 cyl. This plug has decreased the gas millage in both vehicles by 2 mpg. Bosch gaurentees increased millage, a hassle to prove after the fact.