Which Spark plug for 500hp ?

[gezed]

interested in trying those R5672A-8 spark plugs frankie, i was just searching around and looks like they are non-resistor plugs, does it have any negative effects on electrical components in the car?

[cobrAA]

R5672A-8 is R5672A-8 not BKR,
its a racing copper plug

found those cross-number in the catalogue pdf.

[frankiman]

interested in trying those R5672A-8 spark plugs frankie, i was just searching around and looks like they are non-resistor plugs, does it have any negative effects on electrical components in the car?

nope, non at all

[NismoS-tune]

I ran iridium plugs (.8 gap) for 4 years. I found that once they fouled, they were done. I've since gone to copper race plugs again (R5671A-7, napa part number 4091). Running some #7 heat at 1mm gap... Depends on your ignition system I guess, I found I could run more gap with my setup which I read somewhere that it helps with a better burn? The amplifier helped a lot I guess

[Dragon Humper]

Autolite AR3923 ($3 each). It's a fat ground strap, copper race plug with the strap cut back a little to expose the spark kernel to a pent-roof style head better (ie: us). Never measured the resistance of the NGK race plug but, if it's lower than the Autolite then use that. The less resistance the better, any help to weak coils is a plus.

And yes, the bigger the gap you can run the better. That's why you should start at 1mm and work your way down. Use the least resistance plug you can find. I have seen tests that have found a solid 2% increase in torque just from plug gap in an NA 350 Chevy with everything else left alone (already had ignition capable of supporting a .070" gap).





Jon.

[mitch32]

Alex, try the racing coppers like frank but you may get misfires at high RPM. I did, depending on your cluch, turbo, cams, internals, and how fast your car gains RPM you may need resistor type spark plugs. Racing plugs aren't necessarily good even with the "racing" part in the title. Try to get JIS type spark plugs if you can, the only NGK ones I know for a good price is BCPR7es-11, if I was you I'd buy a few different types of spark plugs from 6 to 9 heat range. Start with 6 and work your way up as needed, especially if you do city driving stay with the hottest plug possible. Hot vs Cold doesn't mean anything in terms of performance, you can run a hotter plug and gap smaller. You also have new coils from my understanding so your ignition system should be good enough for 500whp. Your tuner will be your best advisor for spark plugs. BCPR7es is your best option and closest to OEM that is a 7-heat range and copper (aka cheap). Change your spark plugs every 3000-5000km with coppers (and keep the old as spares). Racing plug is a last resort, and non-resistor is even more last resort. Stay closest to stock as you can.

[NismoS-tune]

I wonder why non resistor plugs are last resort for some people when they make the best spark for some of us? Xs engineering ran stock coil packs and a dli, they had some 800whp?

What are the benefits of the resistor if I already have a trick highvoltage ignition?

[cobrAA]

Alex, try the racing coppers like frank but you may get misfires at high RPM. I did, depending on your cluch, turbo, cams, internals, and how fast your car gains RPM you may need resistor type spark plugs. Racing plugs aren't necessarily good even with the "racing" part in the title. Try to get JIS type spark plugs if you can, the only NGK ones I know for a good price is BCPR7es-11, if I was you I'd buy a few different types of spark plugs from 6 to 9 heat range. Start with 6 and work your way up as needed, especially if you do city driving stay with the hottest plug possible. Hot vs Cold doesn't mean anything in terms of performance, you can run a hotter plug and gap smaller. You also have new coils from my understanding so your ignition system should be good enough for 500whp. Your tuner will be your best advisor for spark plugs. BCPR7es is your best option and closest to OEM that is a 7-heat range and copper (aka cheap). Change your spark plugs every 3000-5000km with coppers (and keep the old as spares). Racing plug is a last resort, and non-resistor is even more last resort. Stay closest to stock as you can.

but mitch... i just bought the exact same racing plug this morning lol!

I do have new coils and coil harness

[Dragon Humper]

Alex, try the racing coppers like frank but you may get misfires at high RPM. I did, depending on your cluch, turbo, cams, internals, and how fast your car gains RPM you may need resistor type spark plugs. Racing plugs aren't necessarily good even with the "racing" part in the title. Try to get JIS type spark plugs if you can, the only NGK ones I know for a good price is BCPR7es-11, if I was you I'd buy a few different types of spark plugs from 6 to 9 heat range. Start with 6 and work your way up as needed, especially if you do city driving stay witiih the hottest plug possible. Hot vs Cold doesn't mean anything in terms of performance, you can run a hotter plug and gap smaller. You also have new coils from my understanding so your ignition system should be good enough for 500whp. Your tuner will be your best advisor for spark plugs. BCPR7es is your best option and closest to OEM that is a 7-heat range and copper (aka cheap). Change your spark plugs every 3000-5000km with coppers (and keep the old as spares). Racing plug is a last resort, and non-resistor is even more last resort. Stay closest to stock as you can.

Says the guy NOT making 800hp. The stock plugs are a total waste of money, at any heat range. You will ALWAYS make more power with a colder plug. You will ALWAYS be safer on a colder plug. A modern engine does not foul cold plugs like knuckle draggers from the '60s. Racing plugs are more a name than radical construction. I have yet to find a non-resistance plug for my car, if I could, you bet your bippy I'd be using it. They only use resistance plugs to cut down on EMF noise in the electrical system, it won't hurt anything, just gets annoying when you can hear it through the radio.



Jon.

[cortexx]

I have a set of NGK Iridiums in mine , been in there since i got the car and havnt missed a beat during highly spirited country road driving , they look like new when i take them out. I use yellow jacket coils on them although that might change soon , have been offered a set of okada plasmas BNIB for a stupidly low price ...

[NismoS-tune]

Okada are nice. Especially if you can get them for less than $600. If you won't buy them, let me know who/where and I'll buy em.

[cortexx]

he wanted less than $600 just waiting on his reply ...

[mitch32]

Says the guy NOT making 800hp. The stock plugs are a total waste of money, at any heat range. You will ALWAYS make more power with a colder plug. You will ALWAYS be safer on a colder plug. A modern engine does not foul cold plugs like knuckle draggers from the '60s. Racing plugs are more a name than radical construction. I have yet to find a non-resistance plug for my car, if I could, you bet your bippy I'd be using it. They only use resistance plugs to cut down on EMF noise in the electrical system, it won't hurt anything, just gets annoying when you can hear it through the radio.



Jon.

I actually am making 800bhp or close to it... I swear by the BCPR7es-11 gapped at 25 thou, and its not the power its the boost mostly. 24.5psi and even had spikes to 30psi, the BCPR7es-11 for 2$ worked a charm. I even work on a formula D car pushing 30psi, we run BKR7's on an SR20 and never have any issues.

[GodziRRa]

By the way guys NGK recommends gaping the plugs to a maximum of < or > .008" or 0.2032 mm. So if you want your gap to be on the 0.031" or 0.80mm, stay away from plugs with "-11" on their codes (AKA wide 1.1mm gap). As per NGK-- The reason for this is the ground electrode and center electrode won't line up properly, hindering spark plug performance.

[Terrh]

Is anyone using the megabuck finewire plugs?

I've just been using BKR7/8/9ES and they have always worked fine.