Missfire.. Assumption

[Guest Robo's]

Well i have been doing some testing.

Currently got a slight modded R33 (read below) still running the cooler and turbo. After reading a Zoom magazine article where 0.9 spark plug gap was the best performer, much better than 0.6 that they tested as well.

Anyway, pulled my plugs out and they were gapped too 0.66 (after last dyno breakdown we closed the gap), and bumped it upto 0.9. Immediately it didnt have that idle miss, but underload down low it started missing (3000-4000) , but was very strong up top 5000+, where it didnt miss a beat. Mind you im pushing nearly 13psi too. Hmmm, so i think it is getting a little too much fuel midrange, maybe i should lean it off with my SAFC. So i dropped the boost back to around 12psi and now no miss. Also, with around 13psi im getting some pinging.

So my assumptions are:

1) If your running hi boost, close the gap, or lean it off, or retard the timing

2) Mild boost should be fine, with a larger gap, say 0.9

Now, im just about to put a Front Mount on, hopefully this is going to fix a few areas of heat

[Steve]

I am running 25psi with 0.8mm gap and no probs

what heat range are your plugs?

[Guest Robo's]

There NKG copper, 6 is the heat range, maybe i should go colder ??

[2rismo]

Yes go to 7's right now and gap them to 0.8mm

Adrian

[Guest Robo's]

Hmmm, 7's , might have to try them

[2rismo]

BCPR7ES-11 Re-Gapped to 0.8mm.

The best $2.60/plug you'll ever get.

Adrian

[Steve]

if you can find BCPR7ES without the -11 on the end, they will be already gapped to 0.8 - but make sure you check the gap just to be sure before fitting them.

[Rasi]

What brand are the BCPR7ES ?

[Steve]

Ngk

[Guest Robo's]

I just bought some, i will whack them in tomorrow and gap them to 0.8