Turbo plugs

[Limbo]

ok after some searching on google i found out these are the next one up from standard. They are super class and are 1.1 OE gapped.
Stupid site was in Inches so i had to work it out

For your ref if anyone is interested


http://www.ngk.com/results_app.asp?aaia=1169490

http://www.ngk.com/results_appNonUS....lMotiveID=1103

[1996ek1]

If i got BKR7E would i have to gap them ?
I just don't properly understand the gapping thing..

[Lukezen27]

If i got BKR7E would i have to gap them ?
I just don't properly understand the gapping thing..

The gap size relates to how hot or cold they spark depending on you application..

[1996ek1]

Ohhh i knew the gap size (where the spark part was) related to how hot or cold they are but i thought gapping was to do with adjusting something else.

I would have thought they were pregapped...

[string]

They are. BKR7E-11 for example is pre-gapped to 1.1mm. This does not mean that your engine requires a 1.1mm plug gap - but it may.

I don't know where this 'hot' and 'cold' business fits in. Sounds like complications for an otherwise simple device.

Big gap, big spark, big burn - with the risk of blowout. Boost? Gap smaller.

Get a colder heat range when you're making more torque per bang to avoid the spark plug being a hot spot for pre-ignition.

[Limbo]

gap is dependent on how easily the spark plug ignites.

The closer the gap the easier to spark, but can lead to premature ignition.

Usually with high performance applications they use a wider gap to insure there is nor premature detonation. They also run an external coil to give a bigger spark to make up for the distance the spark needs to travel

[Lukezen27]

Gap size has no correlation to how "hot" a plug is. "Hotness" or heat range is determined by shell length, how much tip is exposed, and how much surface the "heat" is required to travel through before the "heat" is passed to the head surface.

But gaping changes heat range dose it not?

[string]

But gaping changes heat range dose it not?

No, gapping changes the gap size. Buying a different heat range plug changes the heat range. The two are completely independant ideas.

[Lukezen27]

No, gapping changes the gap size. Buying a different heat range plug changes the heat range. The two are completely independant ideas.

Oh IC

Thanks for the info

[Limbo]

i think i know where your getting at luke. When there is higher heat it is easier to spark. At Colder temps it is harder to spark.

So in a way i guess the gapping does need to be adjusted depending on the setup also, but it depends on what your gonna use as a constant

[1996ek1]

Err i kind of thought the same as Luke, where the gap has something to do with the heatrange..

[TODA AU]

Usually you run the largest gap possible on a turbo set up,
Normally it ends up between 0.8~0.9mm with a decent ignition system.
If the spark is weak, the gap may need to be an small as 0.6mm to ignite without missfire.
It's something you figure out on the dyno whilst tuning & just note it down so next time the owner changes plugs there are no missfire issues.
For Normally Aspirated, 1.0~1.1 is fine. (Same as stock)