Spark plug gapping theory
04-28-2004, 04:55 PM
#1
Drifting
Thread Starter
Spark plug gapping theory
I was just gapping a set of spark plugs for my friend's saturn and was wondering how they come up with the size gap you should use. Would it ever be possible to use this as a way to 'tune' for more power? Is this something you would change with more boost on a turbo, etc?
What about plug temp range? How does one go about determining the correct size to use for an engine (other than looking up the factory spec.)?
What about plug temp range? How does one go about determining the correct size to use for an engine (other than looking up the factory spec.)?
04-28-2004, 05:03 PM
#2
Drifting
Join Date: Apr 2004
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When I used to drag race my Chevelle i tried running differnt gaps and looking at trap speed. I found that the .030 standard gap is small and power can be gaied by increasing the gap to a point. I found that point to be .045-.050, anything more and trap speeds decreased.
to note is that I was running a STRONG aftermarket coil.
I just replaced my stock coil in the 951 with an MSD blaster 2--it runs noticibly stronger and smoother and starts faster.
next is a set of wires (stock on there now) and NGK plugs with a slightly larger gap than factory specs (.010).
Someone who knows more about these motors and who has tried different heat rtanges may be able to tell you what heat ranges work.
to note is that I was running a STRONG aftermarket coil.
I just replaced my stock coil in the 951 with an MSD blaster 2--it runs noticibly stronger and smoother and starts faster.
next is a set of wires (stock on there now) and NGK plugs with a slightly larger gap than factory specs (.010).
Someone who knows more about these motors and who has tried different heat rtanges may be able to tell you what heat ranges work.
04-28-2004, 05:10 PM
#3
Drifting
Thread Starter
So basically you want to run the largest gap that your coil can supply a healthy spark accross (too large a gap = weak spark or no spark, too small a gap = lost power?). So in theory the best way to capitalize off a better coil, wires & plugs is to increase the gap slightly?
04-28-2004, 09:12 PM
#5
Burning Brakes
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yeppers
You boost your spark you can up your gap. Or you can buy an msd box and increase the spark that away.
If your really lookin for every last drop you can get, index your plugs as well.
You boost your spark you can up your gap. Or you can buy an msd box and increase the spark that away.
If your really lookin for every last drop you can get, index your plugs as well.
04-28-2004, 10:54 PM
#7
Burning Brakes
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Indexing your plugs is adding very small washers untill your plug tightens down in the correct position. Your putting the arm that the electrode arcs to away from the center of the combustion chamber and the open part where you get your spark closet to the center of it.
I've also seen people take a set of plugs and file them back till the so that it only goes to the center of the electrode instead of all the way over it. Maybe a little gain there but reduced plug life I'm sure.
I've also seen people take a set of plugs and file them back till the so that it only goes to the center of the electrode instead of all the way over it. Maybe a little gain there but reduced plug life I'm sure.
