spark plugs - cracked coils

[TeamKrazy]

a couple of interesting things here,

links on this site recommend that we use BCP7ES-11 plugs in our 33 GTST's, gapped down to about 0.85

and the same plug for the GTR's

after checking out the NGK site and also asking a machanic,

they both say that the GTST should infact be running a BKR7ES

so all the posts about BCP's for the 33 GTR's are rite, but ... here is a 33 GTST senario

so ignoring heat range, cause u can ultimately decide what is best for you.....

wots the difference you might ask,

well 2.5 mms is teh answer,

and where does this 2.1mm come into play?

at the top of teh plug.

the BKR is 2.5 mms shorter then the BCP, so basically what that means is that when teh plug is fully tightended in teh head and you put the coils back on top of them you gonna have 2.5mms extra plug sticking up then you should.

so what? who cares about 2.5mms.

well maybe it could be teh answer as to why so many coil packs are developing cracks and breaking down.

cause when you tighten the coil pack onto the spark plug teh extra lengh has no where to go really?

maybe?

it is just my theory and i thought i would share it with you all.

any views or commentts are welcome.

i persoanlly use the BKR7ES.

also: dont buy plugs with the -11 at the end if you going to regap them, cause you will bend the thing down at an angle and will not get as good a spark as you should.

rather just buy a BKR7ES (they already gapped to 0.80)

[WLD747]

Team Krazy i was thinking about this difference also, as i have just changed my spark plugs.

I recommend the BKR7E. But i think 7's is a little cold for winter. 6's are better suited in our conditions.

The BCP6RES-11 are good plugs if you like your power delivery to be strong and hard. But if you like smooth power delivery and purring idle BKR7E.

Overall i think its just a preference regarding power delivery, but i give the BKR7E a big thumbs up.

Perhaps the length difference of the spark plug (BCP6ES and BKR6E), does affect the coils performance. But i cant comment on any issues. But would like to hear from other members about this issue.

Just another question on this issue. When your gap from stock 1.1 goes to 0.80, i think you loose a bit of power & Strength of spark. Is there a way to keep a high ignition spark? any comments?

regards

AK

[Zahos]

It wont crack the coils even if you press them in hard...

Coils are cracked due to fatigue in the plastic from heat and age...

Gapping 1.1mm plugs down is no big deal, as the spark arc to the tip (points)

A heat range of 7 is too cold for a midly modded skyline. I dunno how modded yours is, but most people should be using a heat range of 6. I would choose 5 if the car is close to stock.

[RB30-POWER]

The coil has a spring loaded type connector that contacts the plug.

With the BCP plugs, you don't even need to apply much pressure to get the coil down and bolted to the plate/retainer. (If that makes sense) So i dont think its under any stress. The spring will take up a good few mm easy.

I dont think this is the problem with cracking at all.