R2558E-9 ngk race plug

 

Thanks...

I don't have a NGK chart. Is that identical to the OEM plug but 1 "notch" colder?

Alexd

 

Yes SKU: R2558E-9 Is one step colder.

See here:

NGK Racing Spark Plugs - R35 GT-R

NGK Racing Series plugs are engineered to withstand the harshest engine conditions. Fine wire iridium tipped center electrode and platinum tipped ground

rampagefab.com

 

I run E-85 in both my Nissans and I use a traditional style (non iridium) silver core plug.

 

Thank you.

I have no knowledge of what's better in the construction of a spark plug, but I would comment that among precious metals, iridium has a much, much higher melting point than Silver. Again, whether than makes any difference for us, I don't know. Iridium is also hundreds of times more expensive than Silver, when Troy Oz. are compared.

Alexd

 

I would go with the ngk race plugs. Tons of top builders use them. Just my two cents.

 

In my experience, the iridium plug design makes for a great glowing red “hot spot” under extreme boost, that is prone to cause detonation. They are fantastic in daily driver cars, and will last forever but they don’t have a place in my high horsepower engines. Copper/silver core plugs in the correct heat range with the conventional ground strap, for me from now on.

 

Not arguing...
So your experience is that the shorter life for non-iridium plugs is more than offset by less possibility of detonation.

Alexd

 

Yes, because of the fine wire design associated with modern iridium plugs. I run non projected tip of course. A projected típ is more likely for detonation.

You know all this already, but the NGK race plug is copper core and retracted tip. And is supposed to be better at tolerating detonation without fracture of the ceramic, compared to regular duty.

I have fractured the ceramic before with STD duty fine wire, projected tip, iridium NGK plugs with devastating results. Data log showed good AFR and still the engine detonated for no obvious reason, and fractured the ceramic in 4 of 6 plugs.

The R2558E-9 is a great plug, but they are like $40 each. You could run those or something similar.

My concern is the fine wire glows like the sun.

 

As a tangent to this, long ago with a nitrous Camaro Z-28 I ran a type of plug made by a small private company that wasn't a true surface-gap, but had essentially 4 ground electrodes without any projections, "firing" across the ceramic. I never had any problems with these, but with GT-Rs I forgot about doing any experimenting in that way.

Have you heard of that, or something very similar?

Alexd

 

Yep, lots of choices out there now.

Something like this? (These plugs are supposedly turbo applications)

 

these are the one step colder than stock plugs - R35 NGK Heat Range 9 Spark Plug - T1 Race Development