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View Full Version : Side Gapping Plugs & getting more power out of your car!



Limbo
23-06-2009, 05:36 PM
I came across this when looking into increasing my gapping due to coil increase.
This seems like a cheap way of increasing sparkage without the added cost

*Disclaimer* - Use at your own risk! i don't take any responsibility for your actions

http://www.pakwheels.com/forumreply_az_TopicID!52957~ForumID!27~page!4~pw.h tml

Subject : >> DIY: Side Gapping Spark Plugs For Extra Gain <<
I have talked about this a number of times previously but this article talks in much more detail. Hope you guys make use of it and talk about your experiences on here.

SUBJECT: Side Gapping Spark Plugs
PROBLEM: Improve spark with standard plugs instead of paying triple for Split-Fire� type plugs
COST: Time only
TIME: 30 minutes
WHAT'S NEEDED: Your favorite spark plugs (Motorcraft or Autolite preferred), feeler gauge,

DETAILS: One of the problems of buying the "premium" type spark plugs, is not only the initial cash outlay, but the hesitation to replace them at sooner than "normal" intervals. Hesitation to replace expensive plugs when attempting to diagnose an unknown problem is common and many times can waste a lot of time in the diagnostics procedure, especially when it turns out the plugs were the culprit.

SOLUTION: First, obtain a high quality over the counter version that carries an economical price. Motorcraft and Autolite come to mind for their performance and safety features of inherently melting before the piston does. Then carefully shorten the electrode arm by taking a die grinder with a small cut-off wheel and remove a small portion from the end. *Do not* nick any part of the center electrode or porcelain! As seen in the photos below, nearly the entire center electrode can be seen from the bottom of the plug as compared to the standard version being completely shrouded from view. This modification will expose more of the generated spark to the combustion chamber, thereby more completely igniting the air/fuel charge instead of the spark being forced to propagate in a sideways direction and not directly into the majority of the combustion mix. This procedure of exposing the electrode is called "Side Gapping", and has been a well kept secret for many years in the racing circles. While some may debate the amount of Horsepower, Torque & Fuel economy increases, there is no disputing that side gapped plugs significantly improve spark propagation as well as reduce plug fouling and loading up, with no sacrifice to your wallet.

The sharper edges also encourages the spark to ignite quicker and stronger, much like striking an arc with a welder on an edge rather than a flat surface. However, there is one minor drawback, and that would be the center electrode will wear one side sooner due to the spark now being directed to one specific area on the plug edge, rather than a random path all around the electrode point. Even though the plugs may wear slightly quicker, since your home-modified plugs can cost up to four times less than that of "premium" versions, they can be more readily changed, leaving you with fresh new plugs during your engine's operation more of the time than with the costly premium versions.

As the photos show, the side gapped plug exposes more of the spark path to the open combustion chamber than the Standard version, as well as even the Splitfire� or Bosch+4� types. And this can be done to any of your favorite brands of plugs you already like, to make them better!

To gap the new plug, slide the feeler gauge in at a 45 degree angle to read the tightest clearance between the center electrode and the arm. Slightly tighter than OEM recommended gaps can be taken advantage of, measuring the actual space between the closest surfaces of the two electrodes. Reduce gaps by approximately .010". Closer clearances will yield the same if not more of the spark front, and at the same time resist the flame from being "blown out" when using Nitrous Oxide injection or supercharging. The closer "sharp edged" surfaces will more easily propagate the initial spark while the main mass of surface area being farther away, will increase the spark travel (volume). Re-gap periodically, as the accelerated wear on the electrode edges will increase the gap sooner.

NOTE: Side Gapping spark plugs has been the serious racer's secret since the early 60's. Only recently have major manufactures started producing this style of plug for mass production, but with unreproducible sophisticated designs, since if their expensive plugs looked like these, they would lose all their business to home mechanics copying that simple to do at home design. Experiment with different configurations and� Have fun!

PHOTO: ��...The left photo illustrates the shrouded standard type plug (red arrow) "squeezing" the spark sideways rather than downwards directly into the homogenized combustion mix in the cylinder such as the newly modified Side Gapped version does (yellow arrow). The Yellow graduation shows how much of the arm that was cut off. The right photo compares three types of plugs. Note the center electrode exposure the combustion chamber sees.


http://www.pakwheels.com/images/forums/2007/8/3/img110_P58_PakWheels(com).gif

http://www.pakwheels.com/images/forums/2007/8/3/img111_ST3_PakWheels(com).gif

http://www.pakwheels.com/images/forums/2007/8/3/img112_PYF_PakWheels(com).gif
Cut the electrode arm off even with the edge of the center electrode. *do not* touch the center electrode or porcelain!

http://www.pakwheels.com/images/forums/2007/8/3/img113_Y79_PakWheels(com).gif
Carefully file the edges of the electrode arm to remove any remaining burrs, but keep the edges clean and sharp.

http://www.pakwheels.com/images/forums/2007/8/3/img114_Z64_PakWheels(com).gif
With a feeler gauge, set the gap at the narrowest point between the center electrode and the electrode arm. Reduce the gap by .010" than norm specifications.



http://www.pakwheels.com/images/forums/2007/8/3/img115_RP4_PakWheels(com).gif

http://www.pakwheels.com/images/forums/2007/8/3/img116_VGR_PakWheels(com).gif

http://www.pakwheels.com/images/forums/2007/8/3/img118_RL4_PakWheels(com).gif
The increased electrode exposure guides the angle of the flame front down towards the center of the combustion chamber promoting a faster, more complete and even burn thus increase power, performance and fuel mileage as well as reducing plug fouling.


http://www.pakwheels.com/images/forums/2007/8/3/img119_WN9_PakWheels(com).gif
HOW SIDE GAPPING WORKS: The closer gap (1-Yellow) allows for easier ignition while the angled surfaces (2-orange) allow the ignited spark to grow in size to exceed that of normally shaped plugs. As the spark column flows along the electrode surface it grows outwards in size towards the combustion chamber and down towards the piston (3) creating a larger spark presence but with an easier starting spark for situations where more spark is needed, such as high compression cylinders, high rpm's and increased fuel conditions as well as preventing "spark blow-out" in nitrous and super/turbo charging applications.

beeza
23-06-2009, 07:13 PM
That looks sweet Limbo (I will read properly when after this bloody headache passes - ALL DAY DAMMIT!!)

CRXer
23-06-2009, 07:33 PM
no real need for this sort of stuff on todays plugs & combustion chamber/cylinder filling designs.

no real need to play with your stock ignition system at all,unless your making like 400+HP.

JohnL
23-06-2009, 08:55 PM
I used to do this 30 years ago (ouch...). I'd be amazed if after doing it you could actually feel any power increase (placebo affects may apply...), I never could. A rolling road might show a miniscule improvement, but then it might not.

Note that sparks like to propogate from sharp corner to sharp corner, and having sharp corners on the two electrodes helps produce a healthy spark. This is the main reason why old plugs with eroded rounded electrode corners misfire more easily. It's also why you see elctrodes with 'U' and 'V' sections and split tips, i.e. more sharp corners.

Limbo
23-06-2009, 08:59 PM
dunno, i've got a new coil and i can feel the difference in it, and this is without tune or adjustment. If this mod is even half as effective i'd do it, just something i thought might give some of the guys out there a little edge without costing too much.

The idea seems to make sense, and i don't see it as dangerous as any of the other power mods.

Its the poor man's ignition power increase.

JohnL
24-06-2009, 06:43 PM
It certainly won't hurt, so I wouldn't discourage you from trying it to see whether or not it really makes any significant difference. It would be very intersting to see some back to back dyno pulls.

My understanding suggests that 'side gapping' won't make the spark any bigger as seems to be implied in the blurb. What it does do is to allow the 'flame kernel' to grow in it's very initial stages without having to 'grow' around the outer electrode, i.e. the outer electrode 'gets in the way' of the newly born and growing flame kernel to a slightly lesser degree than would be the case with an unmodded electrode.

This may result in a less 'deformed' early flame kernal that remains less 'deformed' as it grows and traverses across the combustion chamber. This may (or may not) result in a more efficient burn, but I have my doubts...

JohnL
24-06-2009, 06:48 PM
dunno, i've got a new coil and i can feel the difference in it,

You shouldn't be surprised if your new coil is replacing a worn out coil. A weak coil will give a weak spark, and a significant number of 'power strokes' may misfire, even if you can't feel the engine running roughly.

CRXer
24-06-2009, 07:25 PM
This may (or may not) result in a more efficient burn, but I have my doubts...

agree,todays motors are already very efficient in the burn,it leaves little room for improvement with just spark tricks.

JohnL
25-06-2009, 07:26 AM
,it leaves little room for improvement with just spark tricks.

And the stock ignition systems are extremely good, so it's a waste of time and money fitting higher output coils etc.

Slaz
25-06-2009, 07:51 AM
And the stock ignition systems are extremely good, so it's a waste of time and money fitting higher output coils etc.

The honda system is pretty good but when you go high in comp, boost and or revs it does have it limits, side gapping does work but then you still have the problem of a standard plug and the electrode arm wearing rather quickly opposed to platinum or irridium plug so frequent changing would be required to keep your gap at the correct length, opposed to just tapping it in when they become worn to get abit extra out of them

Limbo
25-06-2009, 01:12 PM
yeah my original coil was fine on the dyno, no misfires.

I've just installed a cranes coil as a precaution cos as Slaz said boosted is a different beast.

The side gapping is only to slightly improve spark, not to make the sparkplug last any longer, i may give this a go later once i get the car running well.
I'm running plantiums so hopefully they last longer

CRXer
25-06-2009, 01:36 PM
when u start seeing 250-300kW+ on your dyno sheets,then yeh,maybe start looking into aftermarket ignition,until then,your just carrying extra weight under your bonnet for no reason,extra parts to complicate things & some aftermarket engine management systems can become tempremental using some aftermarket ignition systems.

look at deanos build,200+kW & not a lead wire out of place.

destrukshn
25-06-2009, 01:44 PM
mine started misfiring at 220kw.
was fine at 200kw.
standard ignition system, besides ngk leads, which were quite new anwyays, with heat range 7 plugs gapped at 0.9mm

currently using (suggested by slaz, and not looking back haha) motec CDI, external, crane coil, magnrecore custom leads, and heat range 8 plugs gapped at 0.7mm.
currently pushing 250kw and no problems or misfires, what so ever.
also using a s300 ecu.

CRXer
25-06-2009, 02:12 PM
how was the health of the original oem parts?
wiring,rotor,cap,coil,icm?

Limbo
25-06-2009, 02:35 PM
yeah didn't get the CDI

I've got a cranes coil, vision cap & vision leads, NGK platinium plugs gapped at 1.1mm i believe with a 6 rating

Previous setup was 162kwatw, this time prob abit more....

beeza
25-06-2009, 03:59 PM
My set up is:

MSD box,Cranes coil,Modified Oem dizzy cap,Oem leads,NGK Iridium plugs - high heat range with a 1.3mm gap (misfires at 1.5mm).

And I am pumping out 69kws! LOL!!

CRXer
25-06-2009, 04:46 PM
sell the ignitor & coil beez,put the money on red or black a few times & ur chances of better results will improve dramatically.

fatboyz39
25-06-2009, 05:07 PM
Stock ignition system is more then enough. We run standard ignition on our mild built b20with E85.

Limbo
25-06-2009, 05:12 PM
hmm i wonder how big a gap i can run

Breeza - which cranes coil u got? i got the LX91

Slaz
27-06-2009, 08:07 PM
Stock ignition system is more then enough. We run standard ignition on our mild built b20with E85.

Your not looking at 200+KW or the cylinder pressures that turbo engines produce that literally blow out the spark, 150KW/12-13.0:1 would'nt present a problem for the stock ignition system.

In saying that, people both n/a and boosted produce big power on stock systems, but they will pop,fart,carry if every component isnt near new and then rev's play a factor as it is often raised considerably with most of the engines producing big power.

beeza
28-06-2009, 05:54 PM
hmm i wonder how big a gap i can run

Breeza - which cranes coil u got? i got the LX91

Sorry Limbo,missed the post.

Yes the LX91 also,dsp26 recommended it to me.It's great,definately a great coil.

Where is dsp26 these days,haven't seen him for ages...

TODA AU
28-06-2009, 08:48 PM
hmm i wonder how big a gap i can run

So everyone knows...
The gap ended up at 0.8mm (10psi - 11.8:1 AFR)
There was a nissue with 1 plug lead also that needed to be recrimped.
So the miss fire in the top end could have been either the plugs at 1.1mm (likley)
Or the spark lead that fell apart when checking the plugs (less likley)

JohnL
28-06-2009, 08:54 PM
Yor the cylinder pressures that turbo engines produce that literally blow out the spark,

When a power stroke misfires the spark doesn't get "blown out", it fails to eventuate. When cylinder pressure is increased it takes more voltage to jump the plug gap with a spark.

This is why you can get a plug that sparks fine when not installed in the cylinder (i.e. at atmospheric pressure), yet fails to fire the cylinder when it is installed. This is also why such high voltages are required in the HT side of the ignition system (if it weren't for cylinder pressures then much lower voltages would work fine), and why some OE coils (typically older designs, pre 'electronic' ignition) need to be replaced with higher output units when CR is raised or the engine is supercharged.

fatboyz39
28-06-2009, 09:55 PM
Your not looking at 200+KW or the cylinder pressures that turbo engines produce that literally blow out the spark, 150KW/12-13.0:1 would'nt present a problem for the stock ignition system.

In saying that, people both n/a and boosted produce big power on stock systems, but they will pop,fart,carry if every component isnt near new and then rev's play a factor as it is often raised considerably with most of the engines producing big power.

Oh... hmm if i add a blower to the end of the motor it might hit 200kw? meh ....

stock ignition ftw :thumbsup:

You turbo lads stop fiddling around with tiny stuff and start racing.:wave:

CRXer
28-06-2009, 10:21 PM
when people have successfully built 900HP on top of stock honda ignition systems,u really have to ask yourself what is really the problem with my 2-300HP motor.
like,am i just covering up some other problem with a bandaid fix.

when u add the aftermarket ignition system,u really have to ask,is this gonna introduce more little intermittent problems that will cost me a possibly a small fortune to trace & rectify if its not a tried & tested product, & possibly installed without a bit of thinking about the cabling & placement of the parts.

fatboyz39
28-06-2009, 10:25 PM
when people have successfully built 900HP on top of stock honda ignition systems,u really have to ask yourself what is really the problem with my 2-300HP motor.
like,am i just covering up some other problem with a bandaid fix.

when u add the aftermarket ignition system,u really have to ask,is this gonna introduce more little intermittent problems that will cost me a possibly a small fortune to trace & rectify if its not a tried & tested product, & possibly installed without a bit of thinking about the cabling & placement of the parts.

Oh wells ...we all gotta waste thousands before we learn and revert back to stock systems aye.

beeza
29-06-2009, 11:18 AM
when u add the aftermarket ignition system,u really have to ask,is this gonna introduce more little intermittent problems that will cost me a possibly a small fortune to trace & rectify if its not a tried & tested product, & possibly installed without a bit of thinking about the cabling & placement of the parts.

So True :thumbsup: