josh's ep3

What are you guys running for your spark plug gap? Is there any advantages to running a little larger gap? Sorry if this is a dumb question, I'm just SUPER bored at work haha.

Type-Spaz

gap depends on several variables.

-type of plug
-heat range of plug
-your setup

I'm running iridiums so mine aren't gapped. But boosted and spray guys need to be more aware.

Type-Spaz

Since the gap size has a direct affect on the spark plug's tip temperature
and on the voltage necessary to ionize (light) the air/fuel mixture, careful attention is required. While it is a popular misconception that plugs are pre-gapped from the factory, the fact remains that the gap must be adjusted for the vehicle that the spark plug is intended for. Those with modified engines must remember that a modified engine with higher compression or forced induction will typically require a smaller gap settings (to ensure ignitability in these denser air/fuel mixtures). As a rule, the more power you are making, the smaller the gap you will need.

A spark plug's voltage requirement is directly proportionate to the gap size. The larger the gap, the more voltage is needed to bridge the gap. Most experienced tuners know that opening gaps up to present a larger spark to the air/fuel mixture maximizes burn efficiency. It is for this reason that most racerems add high power ignition systs. The added power allows them to open the gap yet still provide a strong spark.

With this mind, many think the larger the gap the better. In fact, some aftermarket ignition systems boast that their systems can tolerate gaps that are extreme. Be wary of such claims. In most cases, the largest gap you can run may still be smaller than you think.

josh's ep3

OH wow, I learned alot right there, nice. Yeah I'm running Iridiums too, and I think they came pre gapped at .044. Is that correct or should it be lower?

Type-Spaz

the gap on iridiums is set and thats it. with the style of tip you cannot adjust them. You will break the tip if attempted. Preset gap is determined by type and manufacture of that sparkplug. Not sure what my iridium NGK are running for a gap but I'm not boosted so I'm not worried.

Another important thing to mention is for boosted cars cheap copper cold plugs work the best over iridium plugs which are much to hot.

Type-Spaz

spark plugs can be more important than people think. I've seen a 28+ whp gain from swapping spark plugs on a buddies turbo civic.

josh's ep3

Hmm sweet, I guess this wasn't a bad question then haha. Thanks for the info dude.

DaveSi677

Since we are on topic... I noticed that the Type-S's run a colder spark plug then the EP3... I was wondering if I could run the Type-S's plugs and would I notice anything like more power or better fuel mileage?

Type-Spaz

they do it because of compression and power. You will loose power swapping to the colder plug of the ep3. If your car is stock or relatively still stock I'd recommend sticking with the same plug. Maybe just buy some new ones though and gap them a little smaller.

DaveSi677

ok cause in the next month/ month and half I need to do a little tune up... so was just wondering...

Thanks!!!

Jdc5

Damn Type-'S', you really did your homework on the plugs. That is some damn good info.

turboteg2nv

Not entirely true, you can gap iridium plugs, just not the traditional way that you gap copper plugs(prying on the pintle). You need to use needle-nose pliers and gently pull the ground strap.

I would NOT recommend a smaller gap. Optimum atomization and power is achieved from the largest spark plug gap possible without blowing out the spark. On my turbo Integra, the optimum gap was about .032, although I started at .022 and continued stretching the ground strap until the ignition would pop/breakup under boost.

The RSX-S uses a colder plug because they have a higher compression ratio, which is the same reason people will switch to a colder plug with forced induction applications.

turboteg2nv

Type-Spaz

We like to set the gap just shy of the recommended gap. so if its .032 we do .030. But reason for this is a guy told me with a stock ignition system it produces great spark at lower and mid rpm but starts to die off more towards the higher rpm's. So by closing the gasp just a hair it makes the spark easier at a higher RPM on stock ignitions. Now this is also with caps and rotors and wires. Now we have ignition coils so the spark is a lot stronger all around no need to do so.

The smaller gap theory is just something I heard years ago in the shop but times change, parts get bigger and better. But I still kinda cringe and the thought of gapping iridiums... I've always been told never to gap them. I will call our NGK distributor and talk to him when I go back to work

turboteg2nv

^^ I don't blame you, I would hate to pay all that $$ to break a spark plug. I haven't actually gapped iridiums myself, but I know people have done it.

Let me know what you find out