.8mm Gap Vs .65mm Gap

[nsta]

Which would you go for???ive got 2 options....

1) get splitfires, and hope that gapping at .8mm will work

2) regap my .8mm ngk's to .65mm, and hope it doesnt missanymore

either way will i lose a noticeable amount of power gapping from 0.8mm to 0.65mm????ive heard that too low a gap will slow the car down heaps???

[Busky2k]

Try #2, then if that fails, then #1. You shouldn't really notice a loss of power with that gap.

[rev210]

is the spark being blown out? What power/boost/revs are you having spark issues at?

[mad082]

and how old are the plugs? and what sort are they?

[RaseR]

As rev210 mentioned, it really depends on your power/boost and revs the problem is occuring at...

Assuming it's the usual Skyline misfire, my experience is that gapping the plugs down only somewhat resolves the issue in that it no longer misfires, but instead you get a lovely flat spot!

I bit the bullet and bought Splitfires, installed new plugs at 1.1mm gap...worked perfectly on my old R32 that was running 1.1bar at approx 170rwkw...No misses ever again, the car was incredibly smooth through the rev range and I did alot of k's with that setup...in fact, same story with my SII R33...

Gapping the plugs just masks the actual problem, which is a weakness in the ignition system...usually the coil-packs (cracked or compromised in some way).

[R31Nismoid]

Have you even tested the existing coil packs?

[Emancipator]

Funny this exact issue has been going thru my head the last week.

I put the plugs in gapped at 0.66mm from the word go without ever running 0.8mm. Is it worth pulling them out, opening up the gap and checking to see if the spark blows out?

Brent.

[luke20t]

dont open the gap... i heard that if u open it a bit, it gets weakened and could break off and f*ck ya engine!

[Busky2k]

^^ Maybe if you hammer the thing against a wall to close the gap and open it up again to 10mm and then multiply this cycle by 100.

[R31Nismoid]

I call rubbish

Give just give it a shot on your next plug change Brent, saves you doing it twice close together if your not in the fiddle mood

[rev210]

If you are still running the stock turbo etc. then 0.8mm ought to work well enough all things being healthy.

get NGK BCPR6ES or BCPR6ES-11's , if you haven't already and gap them down to 0.8mm initially. These are copper plugs.

When gapping the plugs do not press the gap closed with the feeler gauge still in the plug gap like I have seen some young-un's do.

Have a good look over the coils for any hairline cracks or discolouration. I had an issue with one once and as a fix used generous amounts of high temp epoxy , it might be a temp fix depending on the extent of the cracks.

With the coil cover off you may be able to confirm an issue if in the dark you have a good look to see if there is any arcing.

They do get very hot under that cover and I wonder if nissan may have given them a snick too much dwell time for longevity. The extra dwell would help emmissions I'd imagine but does increase the heat at the same time and possibly reduces the coils lifespan.

[SLY33]

Which would you go for???ive got 2 options....

1) get splitfires, and hope that gapping at .8mm will work

2) regap my .8mm ngk's to .65mm, and hope it doesnt missanymore

either way will i lose a noticeable amount of power gapping from 0.8mm to 0.65mm????ive heard that too low a gap will slow the car down heaps???

no you wont lose power. i have splitfires, and tried larger gaps, even 0.8 i got a few misses here and there, 0.7 works for me.

do the checks as mentioned.. i fixed a coilpack once with a tiny piece of electrical tape.

[nsta]

thanks heaps guys for the advise, i think im going to just go and buy some splitfires....i regapped my plugs to .66mm,and i still get the missing occasionally, but what is worst, my car has a huge flat spot which wasnt there beforehand, this is running 10psi

Is it true 1.1gap will be fine with splitfires or should i just buy pregapped .8mm ngks asadvised.

thanks alot guys