best spark plugs for R33?

[walkoau]

anyone know the best spark plugs to use in an r33 Rb25det?

if so what are the part numbers?

[peter-flint]

I had NGK PFR6A's in my old R33, worked pretty well getting chased by Audi tt's. Wil be fitting some Iridium plugs in the replacement to see how they shape up, been told they are good for 50,000 mls, will let you know in a couple of years time....

[TTT]

I spoke to my mechanic about this and he is a good friend of mine since I've been going to him for close to 3 years and so has the rest of my family so I know that he isn't bullshiting me..

here is what he said..

The normal spark plugs that you can get from NGK or Champion with the normal copper tips will FLOW (if that's the word to use here) more electricity than the platinum and iridium ones.

He showed me some stats from tests that were done at some industry show that he attended.

The only good thing about the platinum or iridium plugs is that you don't need to change them for something like 50,000 kms or more.

The standard copper plugs are supposed to be good for 20,000kms.

And if you're car runs rich (lets face it, most skylines do) then you are going to have to change any plugs you have more frequently.

Don't know about you guys but I am not about to spend a shit load on spark plugs that are simply going to last Longer. I'd rather change them every 20,000kms and have brand new ones in there more frequently, that also FLOW better.

Also, he recommends that cleaning them to get more life out of them is a waste of time.

[Leewah]

I still run NGK Copper plugs in my car with the standard 1.1mm gapping

Works fine. As GTST said, the NGK copper plugs actually do have a higher conductivity (if there is such a word) rate than the plats or iridium. Longevity is the benefit from not using coppers.

[borry]

Leewah, arent the gaps supposed to be .8? i think i was told that an RB25T should have its plugs gapped at .8? please correct me if im wrong? :confused:

[hippy]

so what is the price difference between these normal plugs and these special iridium or platinum plugs?? ball park figure?? if it amounts to the same by replacing them all the time ... then it would be smarter to change the cheaper plugs frequently.

[Zahos]

about $3-4 VS $18-$20

just go the coppers.

Also try doing a search as this has been posted many upon many of times...

the best copper plug i have tried so far is

NGK BCPR6E (WITHOUT the -11 on the end, meaning a 0.8 mm gap rather than 1.1) If you have boosted your car, the plugs will perform better longer at a gap of about 0.65 - 0.7.

[walkoau]

i think the spec for plug gap on an RB25det is 0.8mm

thanks for ur input guys.

[Pawley]

im with zahos

i put coppers in last weekend NGK BCPR7E.11 though (i figured for $20 i would try) car rund fine, well better than it did on the old daggy platniums.

im not fussed about changing plugs more often if im getting a cleaner spark at a cheaper short term outlay.

next time i'll order in the colder heat range plugs

[Xeron]

use copper plugs for sure, the others arent worth it because they will foul if your car runs rich and you just wasted a shit load of money.

and ALLLLWAYYYYSSS gap ur plugs before u install them, just because the packet says there gapped to 1.1 dosn't mean they are, gap em urself and u will see how off they are outa the pack.

[Zahos]

Hey Pawley,

what kinda power figures you got? Reason I ask, is b/c if you go a colder heat range, the plugs will foul very quickly if your car is close to stock. I put a heat rating of 7 in mine (but I only had cat back and boost at the time), and with 2 weeks i had to change them.... (or clean em), so I went back to 6 which was a lot better for my car..

Zahos

[predator]

I just pulled mine out tonight and inspected and cleaned with some sandpaper and metho and seemed to look much cleaner. Not sure whether it will make a big difference but i haven't given it any stick on the road yet.

They were NGK-R code# BCPR6ES - looked pretty much copper to me. Today i did get some pricing on some platinum and irridium ones from Recpo - either $22 each for platinum or $28 for irridium (or was it vice versa?). When i heard that i just said thanx but no thanx. Now that i've checked them i should have just gone the coppers and installed when i had everything apart.

The thingo on the bottom of the bonnet says 1.1mm so that is how they must come out of the factory but anyway we'll ignore that.

Mine were gapped to 0.85 so just left 'em as is. Were fairly dark but i've seen worse. Interestingly noticed some whiteness on the plugs in cylinders #3 and #5 - would that indicate running to rich or lean? What is the firing order of the RB25DET ? I assume that has something to do with it.

[Jengi]

Whiteness is very bad, it means you are running way too lean.

If you are not running with slightly dark plugs (a good indication that your engine is running rich enough) then this will cause some major internal damage if it's continued to be driven hard.

[predator]

on the dyno day we had yesterday the mixtures were pretty sweet.. around 12.5:1

I think it could have been because the previous owner said he was having big troubles with the mixtures a while back. When he put the S-AFC in it fixed the problem.. So the plugs if they haven't been replaced since, the whiteness could be from then. I'm hoping that was the case anyway!

Anyway, i shouldn'a done half a job and just cleaned 'em -- i'm getting new ones.