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I'll be getting my spark plugs changed tomorrow. Now after reading a few threads about spark plugs it seems alot of people are having problems after changing plugs missfiring etc. Most threads each persons using a different plug also.

Now for the RB25DET I was looking at the recomended BKR5EIX-11,s But then read that iridiums fail quite often before there meant to, making them not worth the extra money. Even if they go bad around 25k km i'll be happy to change them at that interval compared to 5-10k km coppers.

My cars completely stock but i'll be putting a turbo back exhaust on soon but dontt think this would bring it too far from stock performance to have to choose different plugs, Just wondering if theres any better suggestions against using these plugs before I go buy them. Also who has them and how long have they lasted you so far?

Edited by S4LVA
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If you are going to modify our car fither with more boost and power go down to a 0.8 gap as a pose to a 1.1. Im running BCPR6ES in my S2 motor until i get a tune as i got told that iridiums are just a waste of money and do fail, also aren't much better than the cheaper copper ones. Just change them every 15 to 20 k's and you will be allright!

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At the moment i'm getting my dads friend whos a mechanic to change them for the first time. I'll watch aswell so I can change them myself next time. So paying $100 for iridiums I dont mind even if I'll be changing them later on if I end up modding the car in a few months.

For the moment I think the full exhaust is all i'll do for now. Then looking at highflowing, fuel pump,ecu tune and all other supporting mods needed but i'm looking at doing that mid next year if i do decide to so thats about 20k km away.

But apart from that i'm still having second thoughts on the iridiums. Should I ask the mechanic to put them in normal or .8?

Edited by S4LVA
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I work at a Nissan and Mazda dealer ship and we recommend that you use iridium's! But i believe iridium's were made for stock set ups and as soon as you start fouling up plugs running more power, boost, fuel etc it doesn't seem worth it to pay the price of plugs when you can get the same out of copper ones.

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I'll be getting my spark plugs changed tomorrow. Now after reading a few threads about spark plugs it seems alot of people are having problems after changing plugs missfiring etc. Most threads each persons using a different plug also.

Now for the RB25DET I was looking at the recomended BKR5EIX-11,s But then read that iridiums fail quite often before there meant to, making them not worth the extra money. Even if they go bad around 25k km i'll be happy to change them at that interval compared to 5-10k km coppers.

My cars completely stock but i'll be putting a turbo back exhaust on soon but dontt think this would bring it too far from stock performance to have to choose different plugs, Just wondering if theres any better suggestions against using these plugs before I go buy them. Also who has them and how long have they lasted you so far?

Hey there, I thought most people change their plugs because the car is misfiring, not the other way around?

NGK BCPR6E-11 (or -8) copper plugs have been mentioned heaps of times and a lot of people are running them successfully in RB's of various level of modification. I just put in another set gapped to 0.9mm (bog stock except for full exhaust) along with brand new coil packs and the car runs great. I think the plugs were $27 for the set a Supercheap. I think this is roughly half the cost of the iridiums.

Btw. BCPR6E is the "v-groove" version and BCPR6ES the standard one, both should be fine.

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I'll be going down to supercheap tomorrow morning. I havnt checked the book yet but NGK website says PFR5G-11 are the standard plug for the RB25DET. From a search it doesnt look like anyones using them. Just been reading alot of other threads saying coppers a better conductor giving better sparks and iridiums just have a load of complaints against them. So I guess i'll be getting the BCPR6ES or should I get something else. Stock car, with turbo back going on soon. Should we leave the gap at 1.1?

Edit-

Just realised BCPR6ES is 0.8 :P I'll see how it goes tomorrow

Edited by S4LVA
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I just went to autobarn and asked for BCPR6ES and the guy asked what car for. I told him 96 Skyline RB25DET and he cross referenced them with the platinum plug that the book tells you to get. He said I should be using the BPR5ES-11 and I asked him for the BCPR6ES and he just talked to me like I was retarded asking why would you wanna do that. Then told me i'm going to ruin my car and that they wont work. Anyways I bought the BCPR6ES and will be putting them in the car in 30 mins. His just got me wondering if I should of got the BCPR5ES now lol.

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Just realised BCPR6ES is 0.8 :P I'll see how it goes tomorrow

BCPR6ES-8 is 0.8, -11 is 1.1mm.

I just went to autobarn and asked for BCPR6ES and the guy asked what car for. I told him 96 Skyline RB25DET and he cross referenced them with the platinum plug that the book tells you to get. He said I should be using the BPR5ES-11 and I asked him for the BCPR6ES and he just talked to me like I was retarded asking why would you wanna do that. Then told me i'm going to ruin my car and that they wont work. Anyways I bought the BCPR6ES and will be putting them in the car in 30 mins. His just got me wondering if I should of got the BCPR5ES now lol.

That's the heat range, and 6 will be fine on a stock car. Have a look at this and this.

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IMO, dont believe the guys that work at autobarn, but also be skepical of what peaple say here. You'll have no problem finding all the info you need to with a Google search.

BPR5ES-11: the 11 refers to 1.1mm plug gap, which is stock gap. If you're running stock boost and the coilpacks are in good condition running 1.1 is obviously fine.

BCPR6ES: notice that the heat range is now 6 instead of 5? A higher number means the spark plug will run colder

Too cold = more chance that it will foul & missfire

Too hot = more chance that you'll get pre-ignition and lower plug life

Usually the more power you meke the colder the plug you require (as more power = more heat), but the tune is critcally important.

The more boost you run the smaller the plug gap needs to be (or the more powerful the ignition system needs to be), as the more dense the fuel/air mix is, the harder it is for the spark to jump the gap.

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if the car is dead stock and you don't run higher boost, etc then you can get away with heat range 5 plugs. if you have a few minor mods then got the heat range 6 plugs. i would recommend the BCPR6ES plugs. i ran them in my 33 running 14psi and never had an issue. i pulled them out at 10,000kms and they probably could've easily gone another 5,000kms at least. i had iridiums in there before that and they only lasted about 20,000kms.

start with 1.1mm gap plugs (so add -11 onto the end of the part number) and then if you have any misfire issues then gap them down to 0.8mm (you will need a feeler gauge). the other thing is to pull a plug out and check the gap with a feeler gauge. if they only have a 0.8mm gap then just stick with that gap.

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As what I wrote in this thread:

http://www.skylinesaustralia.com/forums/topic/345346-spark-plugs/page__st__20

Hanaldo, here it is in a nutshell.

Iridiums and platinums have the benefit over coppers that the centre electrode lasts longer and therefore the plugs have a longer life. This you have understood correctly.

This is why nearly all cars from factory come with iridiums/platinums and why most people in a standard car run iridiums/platinums.

In a modified car pushing a lot of boost and horsepower the centre electrode and ground electrode fouls up quicker than they do in a stanadard car. Dependent on the tune they can foul up a hell of a lot quicker.

Since they foul up they will start to missfire. This has nothing to do with what the electrode is made out of, it will happen regardless.

Since plugs foul up quicker in a highly modified car, there is not much point using an expensive iridium/platinum spark plug. Hence people use the cheaper alternative, a copper.

Now the added benefit of a copper plug is they can be gapped down when high boost levels are used. You are not ment to gap down an iridum/platinum plug because the electrode can get damaged very easily and render the plug useless.

So yes your tuner is right, however I don't think you will need to go below a 0.8 gap. I have run 20psi and nitrous through mine on a 0.8 copper plug through Splitfire coilpacks and not had a missfire if the plugs were in good condition.

As for the resistor plug, yes he is correct, you are ment to use a resistor spark plug on a RB ignition system. Personally I don't know what the effects are of not running one on an RB are as I have never done so.

So to conclude you want the following spark plug in an RB engine:

BCPR6E

Obviously the heat change is dependent on mods. I use 7's because I need to for the nitrous and high boost level. Other plugs will fit such as:

BPR6E

BPR6ES

BKR6E

etc.

The main differences here are the S on the end stands for "Standard", which means the spark plug doesn't have a V groove on the centre electrode which is ment to give a better burn. So if you can, get one without the S on the end.

And the main difference between the BKR and the BCPR is that the BCPR is slightly longer on the end of the spark plug going into the coil pack than the BKR.

Inside the coilpack there is a little spring that makes the connection between the coilpack and the spark plug. The BCPR compresses this spring more and gives a better contact (once again helps against missfires.)

*I used to sell NGK plugs for years at Autobarn and had many talks with the NGK rep. On a weekly basis I would get guys in imports coming in complaining about missfires due to them running wrong plugs*

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I got the BCPR6ES and took them down to him to put in. We opened up the top and it had a set of platinum plugs still in ok condition. I cant remember exactly what they were, I think PFR6G-11.

Anyways he gave me a massive lecture about how I should get another set of the platinums and just stick with the same plug if it was running good already. Then another lecture telling me not to waste money on modifying, Followed by his other mechanic friend coming over and telling me not to waste money then his friend at bursons also saying not to waste money. Then his auto elec told me to go all out on it :D

So we went out and got another set of the platinums and he used mechanics discount for me :)

We installed them no problems, Except the gasket from one of the pieces that connects to that silver pipe over the middle of the engine fell off and took us a while to find it in the engine.

I still have the copper plugs though which I'll hold onto them for the next change if I end up running higher boost :)

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If you are going to modify our car fither with more boost and power go down to a 0.8 gap as a pose to a 1.1. Im running BCPR6ES in my S2 motor until i get a tune as i got told that iridiums are just a waste of money and do fail, also aren't much better than the cheaper copper ones. Just change them every 15 to 20 k's and you will be allright!

Have i been changing my plugs too often or are you meant to change them every 5k?

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Have i been changing my plugs too often or are you meant to change them every 5k?

you aren't meant to change them every 5000kms, some people just do it. if your coils are in good condition then realistically you could easily get 15 to 20k out of them. if your coils are dying you might get 7000kms. my advice would be to let the next set go for 10,000kms and see if you have any missfire issues. if not then you know you can half your change frequency.

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