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Spark plug heat range - 6 or 7 ??

Gizmo73

By Gizmo73,
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Gizmo73 Proficient

Gizmo73

Posted
Posted

Hey All..

Im looking at getting the iridium plugs (pre-gapped at .8mm), but it seems after searching that people use different heat ratings..

What is the recommended range for a car that would be pushing about 200RWKW in the future ??

I would think the BKR6EIX would be the go - however, if anyone thinks the BKR7EIX i would like to hear...

:P

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The Dan Grand Master

The Dan

Posted
Posted

yes, definately use the 7 as you will be pushing higher combustion temperatures so this plug is better designed for that....also I have more horsepower than this and the 7's are great....don't go 8 or 9 though, very bad.

GunMetalR33 Mentor

GunMetalR33

Posted
Posted

I think 6's are too cold for 12 psi, 7 would do... I run 14 psi with sevens all day long and they work fine. I would only go 6's if you are having knock problems. Sometimes if your plugs are the wrong heat range or too hot like 8's or 9's they can act like glow plugs and cause you mixtures to detonate early in the cylinder causing knock.

my 2 cents, correct me if i am wrong :(

BBQ Community Regular

BBQ

Posted
Posted
I think 6's are too cold for 12 psi, 7 would do... I run 14 psi with sevens all day long and they work fine. I would only go 6's if you are having knock problems. Sometimes if your plugs are the wrong heat range or too hot like 8's or 9's they can act like glow plugs and cause you mixtures to detonate early in the cylinder causing knock.  

 

my 2 cents, correct me if i am wrong :(

Actually 6's are a hotter plug, 7 are a colder. you had it the wrong way round :-)

gtst25 Proficient

gtst25

Posted
Posted

I got sixes then mate/tuner said take them back and get sevens - it won't hurt.

I've had no probs running sevens with stock boost even on cold mornings and there's room for improvement next time we tune and up the boost.

Gizmo73 Proficient

Gizmo73

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  • Author
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allrighty then - looks like im hearing a bit of support for the 7's..

Well ill actually do a correction - i am runing stock boost levels, but with the full exhaust and intercooler its actually running about 8psi at WOT (acording to boost gauge)..

But - thanks for the replies guys - 7's it is.

BBQ Community Regular

BBQ

Posted
Posted
allrighty then - looks like im hearing a bit of support for the 7's..

Well ill actually do a correction - i am runing stock boost levels, but with the full exhaust and intercooler its actually running about 8psi at WOT (acording to boost gauge)..

But - thanks for the replies guys - 7's it is.

I'm running 6's in my car at the moment, with around 15psi, but the plugs have been re-gapped to around .7 - .8, and haven't had any problems, the only reason I would go 7's is if I’m getting detonation or pre-ignition, where the plugs is re-taining the heat and as soon as fuel is pumped into the cylinder it ignites, at the wrong time... But with stock boost you won't have anything to worry about.

So most people go 7's if thier running more then stock boost, and usualy for a saftey thing.

Gizmo73 Proficient

Gizmo73

Posted
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Yep - i just heard back from Repco..

BKR7EIX - not available, according to ngk - they only make them in BRK7EIX-11, which are gapped to 1.1m...and ngk dont recommend re-gapping iridiums...

BKR6EIX - available, $24 each.....

So - for the iridiums pre-gapped to .8m, i think i have to go 6's....

Gizmo73 Proficient

Gizmo73

Posted
  • Author
Posted

Yea i know about the copper - main reason i wanted to go the iridiums is because i can change them way less frquently..

My intercooler piping crosses the block, so i have to disconnect it everytime i change the plugs...

So to go iridiums, it will save me time and $$ in labour...they last about 100k....

Looks like ill be going the BKR6EIX's...

Busky2k Veteran

Busky2k

Posted
Posted

I use NGK BKR7E (V-Power 'grooved' plugs) gapped at 0.9mm. Nope, no misfires, even at 17psi. These plugs are the best ive used (considering the platinums misfied like all hell at 0.9mm) and best of all, they're cheap! Stuff like octane booster fouls plugs easily, so if they are a bit shagged, toss em out and throw in a new set every 10,000ks...

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