I'm curious to know how wide you can get away with gapping your sparkplugs over what the manufacturer specifies on a stock ignition system.

So on a 4 cylinder 1.8 engine with a stock ignition system how wide can you go? If the vehicle calls for 0.035 can you go 0.045, or 0.055 or even wider?

I realize every car is different so all gap sizes would also be different but there has to be a some what safe gap distance that would work on most vehicles over what the vehicle calls for.

 

On single electrode sparkplugs I would ask the same question, But I just got the bosch
Platnium fours, and they come gapped for the specific car you have, and Bosch warns against tampering with it, so I haven't try it.

 

I'm running Splitfire Triple Platinum sparkplugs with a heat range one range cooler than stock.

I noticed better throttle response and low end torque when I installed them. They also came pre gapped but I added 0.005 to what they had and want to know how much more I can go before having problems.

 

yOu realize the bosch plat fours are not made for our car. You are robbing yourself power.

 

I asked for the plat fours for the 98 tib, and he gave the the set that fit it????
I think they work fine, how would that rob me of power???

 

Why difference does it make the length you gap them?

 

Hoping the larger gap would help with performance since the spark would be slightly longer.

 

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" CEL's. (thanks alpine turbo!)

I would NOT reccomend +4 plugs. The small areas between the "4" electrodes allows for carbon built up, which can lead to detonation/preigition.

Also, do a search on 'side gap' plugs. Red posted some really good drawings on how to do it. If you "side gap" your plugs, you should see a performance improvment, using just the stock gap of 0.044"

 

So what spark plugs are good to run in our cars...ie Hyundai's ingeneral?

Thanks

 

So what your saying is that +4 only have probs in hyundais? And to +4s all have the same gapping. Because they use 4 paths of sparking, they dont need to be gapped they are all 4418s.