Iridium plugs

[scuzzy]

:Bang: Ive just bought some iridium ix bkr6eix-11 for my r33 rb25det. I just phoned ngk and they say to leave the gap set to 1.1 as you can damage the iridium electrode.

It states this on the box too, everyone seems to be gapping them at .8

What the??

[TTT]

you don't gap iridiums..

as told on the box and from NGK.

how much did you waste.. I mean spend?

[scuzzy]

$18 each

[TTT]

damn...

did you know or were you informed that copper plugs are better performing plugs than any other out there, and that $4.50 NGK copper plugs would do a better job than those iridium ones?

The only advantage the iridium has over the copper is that the iridium lasts longer.

oh well.

[XtRoN!C]

do iridium plugs make much difference compared to platinum?

[scuzzy]

i know i wanted longer lasting ones

[Black33]

I found iridiums to be much better, got rid of a flatspot for me.

Like the others said, don't gap them, you can buy iridiums pregapped at 0.8mm (have an 8 on the end of the part code)

[scuzzy]

ngk recommend the 11's thou

[GunMetalR33]

I have my irridiums gapped tp .5 and they work fan F8cking tastic. They are NGK Irriway 7 though... I have gapped every iridium plug I have ever owned without any probs including bkr6eix-08's.

I dont see any issue with gapping them down, but I would only do it if you are experiencing flat spots etc etc...

NOTE: Be very carfull when gapping them down...

[Pandaemonaeon]

The Iridiums I took out of my car were absolutely useless. They were a Greddy (NGK) T7340-7 gapped at 1.1mm and the car detonated to hell. Changed them for the el cheapo NGK coppers and no more problems. Used a BCPR6ES with a 0.8mm gap.

[toby19]

I had NGK iridiums with 1.1 for a while then changed them to BCP6RES with .8 gap they were ok for a while...until i fouled the damn plugs. What I did was to re-gap (really carefully) the iridiums to 0.7 mm. I've never looked back since. The car is driving superb.

...I want more power though.

[Bobjones]

I found iridiums to be much better, got rid of a flatspot for me.  

Like the others said, don't gap them, you can buy iridiums pregapped at 0.8mm (have an 8 on the end of the part code)

I have iridiums and the fact is they are great...no flat spot as was evident from the worn out Blitz iridiums and the NGK coppers.

Also the gap depends on the boost level and timing you are running.

Standard boost and timing the 1.1 gap is fine. And don't regap them cause you will stuff them...

The reason I went iridiums is that I got them cheap, $9 each...can't complain...

[JimX]

damn...

did you know or were you informed that copper plugs are better performing plugs than any other out there, and that $4.50 NGK copper plugs would do a better job than those iridium ones?

The only advantage the iridium has over the copper is that the iridium lasts longer.

oh well.

Copper plugs are more likely to melt (lower melting temp, at least one guy in here has melted his copper plugs), and you have to change them every 5000km for optimal performance. Aside from it being a total pain in the arse to do this every 5000km, after 4 changes (20000km) the coppers become less cost effective. If you count labour time as money (even if you're doing it yourself) they're probably less cost effective after the first change. I've had my iridiums for over 30000km now and it still fires as good as the day I put them in.

The reason people usually have problems with iridiums is because of the gap, not the material it's made from.

Edit: Anyone buying iridiums I would advise to get the 0.8mm gap version. I got these by pure coincidence (I got them before I knew what gap they should be or even that there were 2 differently gapped versions) and on a normal tune/boost (150rwkw) it still ran fine. Probably suffered a little bit of economy and power, but nothing noticable over the previous platinums I had and it still ran just as smoothly. Now at 215rwkw it still runs just as smooth and without any detonation and I haven't touched the plugs. Getting 0.8's gives you the scope to up the boost and power at a later date without worrying about detonation. Taking them out to re-gap them is a pain in the arse and you are likely to damage them.

[drifto]

Plugs have caused me major headaches.

After having Platinum fitted without my consent and gapped at the standard 1.1 I had massive ignition breakdown when boosting above 15psi. These plugs also caused a lot of heat build up and therfore detonation even after I regapped them to .8.

I then used an NGK in a colder heat range of 8. These ran a bit rough on the street until decent temperature was there. On the track there were great. They reduce the combustion temp and therefore keep exhausts temps lower and that all translates to less heat in the engine which keep air inlet temps down and water temps under control.

These plugs were shot after the track day, so after recommendation I've gone for the Iridium in the 6 heat range and 1.1 gapped back to .8. There already running a bit rough at idle and were breaknig down on boost but only after cruising on the highway for a while.

I can't see the value in them.

[croat]

I have had irridiums 2 times in a row now. Bought them as a 1.1 gap and fixed them down to 0.8. I have always had boosting issues when over 8psi especially on a cold night, top end 4500rpm and over they just missfire like crazy! I hear that irridium plugs dont go well with RB engines and that coppers and platinums are the best option, any other oppinions?

[Alex Au]

NGK iridium is huge diff than iriway. That's the best spark....I'm trying something new..its OWS twin iridium fm Gemany . as I know the Kart use twin irdium for better ign.....

[JimX]

I have had irridiums 2 times in a row now. Bought them as a 1.1 gap and fixed them down to 0.8. I have always had boosting issues when over 8psi especially on a cold night, top end 4500rpm and over they just missfire like crazy! I hear that irridium plugs dont go well with RB engines and that coppers and platinums are the best option, any other oppinions?

I already offered a pretty big opinion further up.

It seems that most people that have problems with iridiums are either because of the 1.1 gap, or when they have tried to manuall re-gap them. The electrodes are very fragile, it's entirely possible that re-gapping them, especially by 0.3mm will cause some unseen damage and make it not work properly.

I reiterate - I am running 0.8mm factory gapped NGK iridiums (I forget the precise model number or heat range) and I have never ever had a single spark related issue other than cold cranking sometimes (but this is a common unrelated fault, which I rectified with the PowerFC cold cranking settings). I absolutely swear by them, using them in both car and bike. The bike's copper plugs would need to be changed ever 3000km or it would start to burp and fart and lose economy. So far done 20000km on iridiums and the only running issues I get now are to dodgy fuel (i use 95 premium on the bike, which has quality problems in many servos, until I get it tuned for 98RON). Power/economy/starting ease has not dropped one iota in all this time.

I would have gotten platinums for the similar longevity but the iridium spark is stronger. Maybe the coppers do give you a few more kw when new (I've not seen dyno comparisons yet though, so the difference is likely to be very small if any). But let's run them both in 2 different cars for 50000km and see which car is still running just as well as it was 50000km ago. I don't think the coppers would still be in one piece by that stage.

I have a front facing plenum which allows me to get to the plugs without undoing a lot of intake plumbing, and yet I *still* find it a pain in the arse to change the plugs. I set aside around half an hour. At weekend rates that would cost me around $70. (considering I could do overtime and get double time Sunday). Yeah it'd be far less than half an hour if I rushed it, but I then usually end up forgetting something fundamental and having to backtrack and fix it.

[Alex Au]

THE ows & IRIWAY CAME @0.8 & i think its the best gapping. any narrow that this could lead bad fuel econ......

see the sparke diff w/ iriway & OWS..I hv tried to switch the top plug to prove the tester is the same on both side

BTW...is it something the Forum admin has done for me? I can't post image in yesterday but its seems work for now..Thansk!

[CerealKiller]

Alex Au - price?

I had NGK Platinum 1.1's and got them changed to 0.8 Iridiums today and so far seems a tad more responsive...but maybe thats my mind playing tricks on me.