Spark plugs
 

As per TED's request.

What spark plugs do you use? are you not experienced and still go of backwards Mazda OEM recommendations for your engine or have you used something else with great results?

Post and or argue away! open shit fight allowed :gnorsi:

I do not use garbage Mazda oem recommendations, reasons are numerous but needless to say better results in every criteria can be achieved with different spark plug specifications.

My favorites are

Ghetto spec > NGK B*EGV
Mild ghetto spec > NGK B*EGP
Don Mega Spec > NGK R7420 *

* denotes various heat ranges.

I also like using Nippon Denso, need to go through my plethora of spark plug boxes to get you the exact number (maybe I will hide it lol since not many people know about them on the interwebz of shit lol), but its a semi bespoke racing plug which is CNC machined for rotaries, works very well, equiv to the R7420 range in NGK.

http://www.rx7club.com/single-turbo-...1016900/page3/

LO fucking L! at the tards in this ^ linked thread!

Thanks for the info. I'm not making enough power to need the high end plugs :), but it's good to know your reasoning behind the use of certain plugs.

R7420 10.5L 11T for me

So even when running fairly original power, you'd recommend not going with the BUR7EQP and 9 pairing? Just bought new Magnecor plug wires and two sets of those plugs ( :( ?) without really getting into what the differences between the different plugs are at all, planning to eventually get an HKS ignition amplifier as well. Also got a Power FC, running slightly rich.

Going for reliability more so than power. Just want what's the healthiest for my baby :) Got any recommendations, Rice? Just bought my FD now in January, long term plans for it are getting a nice V-mount setup, water/meth injection, ignition amp, blocking out the OMP + going for premixing.

For your set up > R7420 in 10 heat range once you get the HKS DLI.
Reliable plug I have many hundreds in service, never ever had a failure of a spark plug. And in every case the plugs work better in every measure you care to apply.
I have proven these to be the best plug.
E-Bay them there are plenty for sale.

R6725-10.5/11?

^ These are over 30+ years old.

Platinum Platinum combo out of an old Racing Beat catalog lol......... the later R7420 Iridium center option is far superior, much longer lasting and better performing.

It is an acceptable plug, but just not as good as the one I have been using for the last 10 years.

So I suppose four of the R7420-9's would be the best choice for a moderately powered N/A engine (200+ whp @ 9000+ RPM)? I stumbled across these a while back but I always assumed they were race-only plugs (i.e. warm up on stock plugs and swap 'em in).

Awesome, thanks! :hurray:
No idea if it makes a difference, but will these work equally well in cold outdoor temperatures? I noticed you live in Australia, I live in Norway.. :)
And they won't require a much longer warmup will they? There might be times I need to drive it short distances.

I live in Alpine regions of Australia where it is common to be -10 deg C.
The 10 and 11 heat range plugs work totally fine in those conditions, you just need a properly calibrated engine map that is set to work in all operating conditions.

With a proper CDI ignition system (leave inductive for the chumps of the world!) there is never any need to worry about the garbage of a warm up then race plug, that is plain idiotic.

Sounds good!

Sent you PM earlier btw, not sure if you saw that. Was very OT so figured it was better to send it privately :D

Its not about power level. Real advantages of these high end plugs are far better durability and lower voltage requirements for given air gap compared to plugs with more conventional and bigger diameter electrodes.

Less energy you dissipate to create spark, more you have available to create plasma channel - heat which initiates flame front. Fine electrode plugs are also more consistent in sparking which lowers cycle to cycle variation which in turn means more power and better fuel economy.

What about using the R7420's with water/meth? From my understanding there is still platinum in those plugs, and doesn't that react with methanol causing pre-ignition? Any suggestions for someone running water/meth injection?