NITROUS OXIDE ( nos / n2o ) advice forum

I wanna go a heat rating up to prevent detonation, more of a precaution, but there's no direct upgrade for my Clio ( STD heat rating 7 ).

Sierra cossie plugs fit my car and are heat rating 8, ideal? I have two choices. Standard £5 a piece ngk spark plugs, nothin special. Or these fancy iridium plugs at like £20 a plug?

My local mapper said normal plugs give off a much fatter and wider spread spark so is better, but surely a £5 plug wont give as good performance?

Is there anything I should consider for use with nos? The electrodes on the iridiums are tiny, worse for heat?

Thanks.

I use Denso Iridiums at £8 per plug with no problems

i went on the ngk site and they have a part code break down chart i got the number from one of mine and copied the bits i needed like the tread length and size ect and chose one grade colder and lost the 4 electrode setup then just rang a motor factors to see if they existed lol and they did my ones were bkr6equp i think i have bkr7es the originals were 6 quid per plug the ones i have are about 2 quid per plug and iridiums are about 20 per plug

http://www.spark-plugs.co.uk/pages/technical/ngkjpg.htm

What I wanna know is will the cheap STD plugs sufficer or do these iridium plugs actuay offer any benefit?

I don't believe there is much benefit to Iridiums, just run colder standards.
One thing I've been told time and time again is ONLY use single electrode and avoid platinum like the plague.

I`m on NGK BKR8EIX no2668 plugs on a 100 shot and they are doing fine. I usually change them every 7000 miles.

RULES for plugs;

1) ALWAYS use NGK
2) ALWAYS buy the cheapest
3) You can then afford to buy a few spares and change them if any look different to the rest
4) NGK are without doubt the best brand available but even they accept a ONE IN THREE failure rate, so in any set of 4 plugs you potentially have 2 faulty ones.
5) Faulty plugs do not always show up under normal use or in the form of a misfire, plus it takes an exceptional person to detect an 'occassional' misfire at high rpm anyway.
6) If in doubt, CHANGE ANY plug that looks different to the rest
7) If you've tried everything else and still don't get the performance you expected, change ALL the plugs, because they can 'APPEAR' to be perfect and yet still be inadequate, especially for nitrous.

BTW no matter what you pay for plugs there is NEGLIGABLE difference in performance and the only advantage of expensive plugs is that they 'SHOULD' last longer.

IMO I'd steer clear of Iridium plugs. The Iridium tips are welded on & can & do fall off under det! They have claimed a few high ££££ engines in the past I know of & I had a very close call with a Denso Iridium plug after a very small amount of det on a dyno tuning session.

Copper core NGK's all the way for me & everyone I know that's seen the damage cause by Iridium plugs!

Bill

Thats interesting, I thought it was only platinum plugs that did that?
http://www.spark-plugs.co.uk/pages/tech ... -plugs.htm

Platinum plugs as you say don't like Nitrous for some sort of chemical reaction afaik as your link states Iridium plugs don't suffer from the chemical reaction but the tip can & has fallen off (AFAIK) after some det, in my case it was very slight as the car was on a dyno being tuned with det cans etc etc so it was caught early enough to hurt the motor

Bill

Thanks for confirming, another plug change coming up

I'm sure there's loads of people running iridium plugs with no problems but IMO it's just not worth the risk! Copper core NGK's are £2 each from my local motorfactors so they are cheap enough to get a few & pick the best looking ones as Trev suggests

Bill

My only defence is that its a 1-2 hour job to change the plugs on the BMW M62, but I am well aware of the potential ultimate cost when it goes wrong

Good discussion about plugs especially with the increase in temperature, but thankful I already use NGK Plugs at the moment and the suggestion from Trev is to keep with them.

So that's good news at least they wont set me back a fortune, i think mine are around £14 set....ish

My old Ford Galaxy Plugs were £10 each and that was standard plugs!