One of the other members asked me what heat range plugs I was using in my cooupe. I've been using NGK BPR5ES Irdium race plugs but I also know that one of the prep manuals for Datsun Cherry (Rentille74 I think) notes ranges from 5 to 8. Iv not,suffered any detonation so stuck with the hotter / standard NGK 5 although I've given thought to going to a slightly colder 6 or 7.The A15 in my car runs 11:5-1 comp with a moderate cam , ignition advance is 38 degrees and I run 100 octane fuel.

So my fellow A-series racers what plug heat range are you using?

Tom

Hi Tom,
NGK Iridium BPR7EIX4055

Seem to work well and I'm running around 10.5/1, a big cam with 1.65/1 ratio rockers and 98 pump fuel.
Cheers
Dave

NGK BPR5ES/BP5ES was the factory plug for stock A12 (BP6E for 1971)

Nissan competition sold A-series plugs down to BPR10ES equivalent

I'm using NGK R5671A-8/4554 non-projected plugs. 3 colder than the Stock 5 heat range. 8.8-1 compression with 10# boost and 175hp shot of wet Nitrous. 30 degrees timing on boost and retarded 10 degrees on nitrous. 92 oct. Non ethanol with Lucas Oct. Boost additive on Boost an VP Q16 spraying when on nitrous.
I bought a set of 7 cold range last week and will give them a try the next chance I get.

Just cheapies in the circuit A12. BR8ES. E85 30+ PSI

My 1300cc A12 E85 12;8 to 1 comp loves BPR8ES plugs