Best spark plug for e30?

[digger]

I use the BPR6ES too, as a side benefit to working well, they are cheap as dirt and i can go to any small redneck autoparts store in town and find them.

For a stock engine the equivalent would be BPR5ES

ive never gapped them either not sure if im supposed to lol

i dont know what the difference between the ZGR5A that is recommended over the BPR5ES's which i've also used.

[AlexHale]

No interest in E3's?

[mccor023]

they changed the p/n for the B25 bosch plugs at one point W8LCR and then WR8LC or something along those lines.....was apparently still the same plug or newer version but 100% compatible they said

Yeah I know they changed the plugs and "enhanced" the plugs by changing the metal content. I read a post by levie explaining it, and I didnt believe at first how much of a difference it would actually make. But, from my experience the older version does perform better.

[digger]

So who here with modified naturally aspirated M20 gaps their plugs?

i run BPR6ES on my stroker which uses stock dizzy, coil and OEM style leads with Aftermarket ECU. engine makes quite a bit more cylinder pressure than stock engine and i have chosen one step colder plug. interwebs says i will need smaller gap but never actually gaped them.....

out of the box IIRC the NGK are about 0.9 to 1.0mm and the handbook says 0.7-0.8 mm for the M20. so in effect i have increased the gap where theory is i should be closing it up with the stock ignition due to mods.

while i cant say ive noticed a major problem (other than those traced to problems with the spark plug leads) this does not really mean much as from seat of pants you might hear knock or feel a missfire there are other problems that may not be perceived. i do keep the ignition system in top shape and regulatory change plugs, cap rotor and coil

i realise that a bigger gap is better if the system is capable of providing the correct spark
other experiences?

[nando]

I run the same plugs, I just gap them to stock specs.. no issues. I think the type of coil you are using matters too, a stronger coil can jump a larger gap.

[digger]

if you run a CDI system it would make sense to run bigger gap to get more exposure. i might try gaping them down to 0.8mm to see if there is any perceived difference in engine behavior.

[zaq123]

if you run a CDI system it would make sense to run bigger gap to get more exposure. i might try gaping them down to 0.8mm to see if there is any perceived difference in engine behavior.

what did you find out? any difference with oem gap spec?