Iridium NGK Plugs

[nedb]

For early R32 the recommended spark plug is heatrange 5. After finding this out changed mine to 5 and it feels a lot smoother and the morning starts are much better.

With brand new platinum 6's the car would stall a few times in the morning unless I give it a bit of help with the accelerator pedal. I had them for a year.

Since I changed to 5's the car has not stalled once.

[Beer Baron]

For early R32 the recommended spark plug is heatrange 5. After finding this out changed mine to 5 and it feels a lot smoother and the morning starts are much better.  

With brand new platinum 6's the car would stall a few times in the morning unless I give it a bit of help with the accelerator pedal. I had them for a year.  

Since I changed to 5's the car has not stalled once.

are you sure? I'm not 100% but I always understood that all the turbo 32s and 33s used heat range 6 plugs. well if not I stand corrected.

[Col-GTSX]

Richard dont get me wrong im a nice guy...

But im gonna believe the NGK rep as to which plugs to use....

Look at their website and punch in a gts-t 33 and you will fint 5 is the recomended heat rating... Higher heat ratings (colder plugs) will have trouble in hotter climates.... The hotter the intake the hotter the plugs you need... If we lived in temps between -15 and 20 degres then 7 rated plugs would be normal..... Here in humid Brisbane it very HOT HOT HOT....

I have an intake temp monitor and on a stock intercooler i have seen temps hit 80C (thats bad) with 6/7 heat plugs at these temps the plugs wouldnt do anything, it would miss and carry on. If one or two plugs were to fail at 5000rpm at 80C under full load the fuel would pure out the exhaust. The O2 sensor would read rich as buggery and the ECU would lean it out as far as possible...... Keep doing this and you can understand what would happen....

Cheers Col

[RB30-POWER]

Your all a little confused.

With NGK plugs, the higher the number the colder the plug rating is. What this means is the plug can transfer more heat away from the plug the colder the plug is. (higher number)

What happens when you fit colder plugs such as 7, 8, 9 etc etc, in a street driven vehicle is under low load/idle the cylinder temperature isn't hot enough to burn the carbon off the plug tips. And after a while the car will miss because of the fouling that occurs from the carbon on the plug tips/electrodes.

These plugs are great when you are under constant boost at a race track for instance as they remove the extra heat from the sustained high power output from the motor and removing this heat prevents the plug from getting hot and causing pre-ignition from glowing spark plug tips/electrodes.

They do say go one heat range lower when making an extra 100hp more than factory. While most people will say im making an extra 100hp than factory or even more power, the point is, you don't need the colder rated plug unless you are going to sustain the higher output for some time. i.e. race track, drags etc. You only ever give short bursts on the street.

While NGK recommend a heat rating of "5" for some of the RB20/25, you should run a "6". You will get away with the 6 as the climate is alot warmer here than Japan, where the "5" rating is specified. NGK get the recommended rating from the skyline manual. Which is really only applicable in JAPAN.

If you look at any locally delivered car in Aus that is turbocharged, most run a "6" heat rating. Most NA run a "5" rating. Of course there are exceptions, as i said.

If you run "6" and have trouble it won't be related to the heat rating of the plug, thats for sure.

[Col-GTSX]

I agree with the faults thart can occur i just think its crazy that some would run as high as 8... Thats just wrong...

My R33 is mild and has the usual bits and pieces everyone has plus a few extras so 5's are great for day to day round Brisbane. I dont race it and dont do power runs in this car. Its just a little booster so 5's are good....

[The Dan]

why is that crazy, my old rotarysuggest 8 and 9's as standard.

What I would like to know is this....how the hell does your boost blow the spark out. It's got me stumped. I thought the valves were all shut when the plug fired.

[RB30-POWER]

It not really blown out, it just either doesn't spark properly or spark at all.

It because pressurised air in the chamber creates a higher resistance for the spark to jump to the electrode from the tip and the plug needs more energy to make a spark, under those higher cylinder pressures.

Pressurised air is not a good conductor obviously.

[Bobjones]

Sorry I checked mine last night and they are in fact Heat rating 6 not 5...

Obviously the 5 would be too hot...

[Col-GTSX]

Re gapped the plugs to 0.9mm

I am now experiencing a little more power. Cold nights in Brisbane help this also....

Had another long chat today about heat guides on NGL spark plugs....

After taking all the varibles into account i personally believe that everyone has a different opinion.

HAHAHAHA

Thats the safe and most correct responce.

But i will continue to use 5/6's in my car unless future mods change the needs for spark.

[Zahos]

As for iridium supposedly they provide a higher energy charge, and last longer than coppers.  I have only ever run coppers in rotors due to the higher fuel ratios and ease of removal.

Hi Neill,

Coppers actually produce a stronger spark as copper is a better conductor.

Iridium plugs do last longer, and I believe are used in some cuircut cars b/c they they can withstand higher temperatures.

[Col-GTSX]

Copper sheet is widely used because of its unique properties.

Copper sheet is one of the best conductors of electricity after Silver. Copper is more often used due to its lower cost.

Copper sheet is a very good conductor of heat.

Copper sheet can be shaped into any form easily as it does not crack when hammered, stamped, forged or pressed.

Copper sheet is resistant to corrosion and does not rust.

Copper sheet is environmental friendly - it can be recycled.

History of Copper

The name Copper is derived from Cuprum, the Roman name for Cyprian Metal. Copper is probably the first metal to be used by mankind.

Copper is a soft and reddish-orange metal. It is one of the best conductors of heat and electricity. The alloys Brass and Bronze are formed when Copper is combined with alloying elements such as tin, aluminum, silicon or beryllium.

When copper is exposed to moist air containing carbon-dioxide, a protective greenish film known as Patina is formed. This film prevents the surface of the copper material from further corrosion.

But platinum lasts longer under temp and electron passage. In english they will fire more consistantly for longer.

[SPINR33GTS]

I dont no why neone would run a grade 5 sparkplug in a skyline is way to HOT!! ie more prone to detontion due to higher running temperatures the sparpklug itself will run at a higher temperature too!!

something liek a grade 6 or 7 sparkplug shouldnt b an issue due to the nature of a turbo motor running inherintly lean.

ive heard figures of aircooled motors runnning 15 degrees hotter per grade of sparkplug as we all no a skyline motor is water cooled but if u ever opened a bonnet after a drive ull no that the motor doesnt run cold at all if nething super hot...

running a higher number being colder 7<>5 hotter maybe experince fouling of sparkplugs etc but in a nicely running skyline a 7 grade sparklpug shouldnt b an issue also does not really affect coldstart though motor will run a couple of degrees colder.

however ive always noticed colder plugs to increase fuel economy.

Thanks Rory

[rb20inside]

i had ngk iridiums in my rb20, gapped to 0.8.. and my car felt flat, used to miss, felt slow, pretty gay

talked to my tuner and, i'm not sure of the science behind it actually, apparently iridium plugs don't run well with nissan coil packs and i should put in copper ones. so he sourced me some NGK B8EGV plugs and its much better, smoother, powerful

just my 2 cent experience

[RBwhatever]

Well it is a 3yr old thread rory........ but since you brought it up, my experience is, I have bought NGK Iridiums BKR5EIX-11 and have been using them for over year now. Yes thats right heat range 5 and pre-gapped to 1.1mm.

I still run the stock turbo boosted to 12psi with all supporting mods etc and I have not experienced a hiccup yet with these plugs. They haven't missed a beat even in the hot hot heat of FNQ. As for detotnation......what detonation.....

I understand that it may not suit a lot of people, but for me they work a treat.

Edited February 7, 2008 by KeyMaker

[SiR_RB]

so much confusion about what plugs to use lol

on my 95 r33 (series 2 motor) im only runing a 3" cat back exhaust and pod, what model copper plugs should i use ?

i need to change them this weekend....

[subzeroR33]

so much confusion about what plugs to use lol

on my 95 r33 (series 2 motor) im only runing a 3" cat back exhaust and pod, what model copper plugs should i use ?

i need to change them this weekend....

V Power BKR6E or go with a BCPR6ES. will do the job.

[Jimmyr33]

im pulling 371hp and my mechanic/tuner told me to use coppers, he said, "replace them every 4-5000kms, they are $2 each, who gives a f$%k" i just gap them to about 0.8mm (from memory) and im set..

IMO id rather spend $12 on a set of plugs than almost $100... i can buy 8 sets of copper plugs to one set of those fancy ones. 8 sets will last me 40000kms... by the time i reach that distance on my odo, ill prob have wrapped teh car around a tree...

copper = winner

[Trust33]

im using a heat range 7 (PFR7A) NGK R iridium. installed by CRD when i got the car tuned years ago. im picking new ones up this sat along with a fresh oil change it shold be good.

keep in mind that ive done 46,000klm's on these plugs. and they were good enough performance wise to see me through many a track day.

[Col-GTSX]

To add more info to this thread in hindsight;

The plugs gap was half the issue and so was the heat range.

But the biggest issue was old coil packs, not faulty but old. They still worked quite well at stock boost, but as the heat got into the coil packs under hard driving they started to fail and a light show occured under the bonnet (which was discovered on the dyno with the bonnet open and the lights out).

So after investing in a set of splitfire coil packs I was able to re-gap the plugs to 1.1 mm and the car never ran better.

In time I added a GT30 high mount and upwards of 21psi, the plugs and coil packs still performed as good at this level as at cruising speed under no pressure.

Also the heat range has less to do with the problems discussed in this thread, gap and coil condition are bigger issues than heat range.

I now believe in hindsight the following rule of thumb;

Stock boost, heat range of 6, gap of 1.1mm if you have good coils.

Stock boost, heat range of 6/7, gap of 0.8mm if you have old/semi faulty coils

Stock boost, heat range of 5/6, gap 1.1mm if you have new/splitfire coils

Up the boost 16+psi, heat range 5/6, gap 1.1mm if you have new/splitfire coils

Up the boost 20+psi, heat range 5, gap 1.1mm if you have new/splitfire coils

Up the boost 25+psi, heat range 5, gap 0.8mm if you have new/splitfire coils

(You must have a set of good/new coils if you ever plan to run big boost, as saving money on good coils could cost an entire engine)

Ps. Heat range will change depending on where you are in the world, average temps in Brisbane are hardlly ever lower than 10 in winter and hardlly ever higher than 40 in summer.

Also different cars will act different way, depending on timing and ECU performance. So there are a few variables to consider when reading the above advice...

Hope this helps...

Hindsight is a wonderfull thing...

[OnAhigh]

is there a way to test the coil packs? as i changed my plugs to iridiums last week. gapped to .8mm heat range 5. car was running fine for a week then yesterday all of a sudden it just started running like shat, keeps missing feels like its running on 5 cyclinders. pulled them out had a look all seemed fine, then when i put them in again the car ran fine for a few hours then half way to the city bang the problem came back. kind off feels like the coils are playing up or sparks are no good. no idea but im tired off pulling everything apart over and over again. any ideas?