Gap Size

[Xtrm]

What is the best gaping for spark plugs on a 2003 3.4 GLS?

[Spilner521]

Stock engine or highly modified?

[Xtrm]

Its stock right now. And would it make any difference when i put my air intake back on in the spring?

[Spilner521]

If your getting aftermarket plugs, whatever they're gapped at when you take them out of the box is just fine, and no the intake will not affect it.

You can leave your intake on during the winter if you want, nothing bad will happen.

Only when the engine is highly modified or boosted is when you need to tighten the gap a little so that the high cylinder pressures won't blow the spark out.

[Cliff8928]

.060" gap is recommended by GM.

[bryan213]

never juts put the plugs in from the box always gab them

[Nate's Alero]

well there are some plugs that dot need to be gapped

[[ion] C2]

i always just install em right out of the box lol

[billytheman1188]

hmmmm.....i think they have gap sizes in the manual for a reason.:rolleyes2: but yea, .060 is what i have mine at.

[jayson_waltz]

gap makes no difference unless you have a highly modified engine, then you need to close it up to avoid blowout. just use them how the are out of the box.

[Xtrm]

Alright. Thanks alot for the info :)

[Xtrm]

PLugs are in ..car seems to be running better :D

[Spilner521]

never juts put the plugs in from the box always gab them
Says who? I put my Denso Iridiums in my car right out of the box, and it's ran perfect for the past 3 years at 8psi of boost.

[[ion] C2]

Edit: Nevermind, you're supposed to gap 'em for maximum performance.
3. Gapping

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 racers add high power ignition systems. 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.



Now I understand some of the reasons people put higher power ignition systems in.

[Redog]

Yeah .060 here too.

Should be at .060 right out of the box, but the last time I did it 5 were right and 1 was at .030 :eek:

[Cliff8928]

Says who? I put my Denso Iridiums in my car right out of the box, and it's ran perfect for the past 3 years at 8psi of boost.

You have to be really careful gapping the iridiums too. They tend to break VERY easily.

Most plugs have a certain pre-set factory gap. Some have it labelled on the box or the plug (like on NGKs, it's the number under the part number)