Previous post discussion.
Back from the dyno and we learned even with the iridium plugs they were not the right choice in terms of cold range selection.
Datalogs recorded show quite a lot unhappiness which we can only image if it was a cooper plug it would be worst.
So we switched to a race spark plug
(note: your mileage may vary since our setup is for a race car).
This pretty much solved a lot of issues for ignition delivery.
There is an issue, when is there not? These race plugs do not have a resistor core. Which means they are subject to noise from electromagnetic interference. So far my limited records through datalogs don’t show any spikes for ignition. Which also means very little as I need a oscilloscope to really see what is going on. Maybe the NGK race spark plug wires are dampening (ok, I doubt it)?
To remove RF issues we would install NGK BKR10EIX-11 (Fine .6mm Iridium projected electrode tip, tapered strap), but I can’t get this.
In case your looking for these plugs for your B18B:
Part Number: R5400 –> R5400F –> R6337 –> R7435 (8,9,10) –> Part Number 4897
If the price has turned you off you can opt for the V Grove race Seires. I am told by a NGK Tech they share the same design and specification except for the precious metal in the core.
R5672A-9 (Non-resistor, 2.5mm V-groove projected electrode tip) –> 5554
They also have a colder plug R5672A-10 (Non-resistor, 2.5mm V-groove projected electrode tip).
Both of these plus are part of their race series so you will have to ask around.