Quote:
Originally Posted by Bucketlist
I have run the W3DP0 on the top since I have had the car. A few years ago I considered replacing them but they looked good so I reinstalled them. At that time I found this crossover chart. The BP8ES is about $3.50 compared to the $38 for the W3DP0. This is all I know and look forward to the results of your research.
My bottom plugs are NGK D8EA |
Here is a cross reference list from NGK
Most of what I'm reading says that it's not good to use resistor plugs in a CDI ignition.
I know that Chris at Turbokraft recommends the NGK BKR8EIX, but some say that is because he's mostly doing inductive builds (without CDI).
NGK Part finder (click on "Cars,Trucks,SUV" then "Part number")
Looking up BP8ES, it's a solid copper core, with 1 Ohms of resistance. Your D8EA's are also 1 Ohm of resistance.
Note that NGK also makes a BPR8ES which has 5000 Ohms of resistance.
In comparison, the BKR8EIX is listed at 5000 Ohms of resistance.
I forgot to note the source and the exact quote, but there was mention in an article that both the resistance of the plug wires and the plug itself is overcome to move the energy from the coil across the plug gap.
I know the Bosch silver ignition coils have a reputation for a high failure rate. I wonder if any of that could be associated with too much resistance in the plugs? I'm not an EE here, just a guy with a Porsche trying to figure it out.
Several of the places I've checked in order to find a better price for the Bosch W3DP0 said they can't even order them. Not sure if that's just a retail failure or has some further meaning.