Cooper S R56 N14 spark plugs

Bilbo said:

Mike what did you mean by they are hard?

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iridium plugs are harder plugs designed for very high temps and big power where the combustions processes are very high but harder the metal the more dense it is this causes a high resistance for the electric protons and ions makes it harder for them to travel through a higher resistance metal like iridium,, on n18 they have increased the output to produce a heavy spark,, the plats is less resistance and allows them to travel with what can be produced from the coil pack,, a coil pack is a capacitor has windings and non conductor screens in side as such,, so 12v charges this via main ecu the capacitor saves this and amplifies its 10amp 12volts to maybe 240.000 volts at 00.10volt ie low volts high amps this gives a lightening effect ie the spark,, as its tiny volts its hard fro the coils to power through high resistance ,, the switching on this circuit is ecu earth switched so the ecu cuts and engages the earth circuit only as control this prevents spikes back to ecu and better control,,,
so car makers would of spent millions on this design around the plugs and engine to get it to run in a way that will last,, if wrong plugs can cause pinking or knock where the system is designed to give a timed spark allowing for slight delay in the journey from ecu to tip of plug,, increase the resistance reduces the spark and delays it slightly,, might not notice this at low revs as much but when bouncing off the top end where a spark is happening will ,, i found when used iridium's in the past i got more back fires on over runs,, the guy i use for repairing high pressure fuel pumps explained this to me a few years ago and it does make sensor,, hence why you can now buy stronger coil packs for n14 cars and the cars with 300bhp and forged use them and with the iridium plugs as on those cars work really well ie less risk of melting the tips of them when running big power .
below link best coil packs

Bilbo said:

Thanks Mike, that makes a lot of sense, thanks for all that write up.

My coil packs been replaced by BMW 6 months ago and I see no point replacing them at this point so I'll go with platinum plugs as mine will be a very boring street car.

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plats are good plugs think people read stuff on internet but dont read it all, ie get someone who has melted the tips off a plat plug but dont tell you that he's also had a lean out and that was why and nothing to do with the plug,, on a forged with bigger boost and fuel to add then they go with hard plugs and better coils,, no brainer on that ;level, i got a n14 booked in for next month that is having it all done and will have those coils and indiums forged and better turbo as well bored out max etc, also golf a monster to do as well vw golf r32 pull engine forge it and chain kit bored as well and some head porting and valve work etc, then its having a twin scroll turbo fitted from a kit £1400 for the kit aiming at 600bhp might even go down road of a super charger as well,, that v6 3.2 engine is so strong for the off and most people run a mile form them as so expensive for parts ,, just one camshaft adjuster ie vanos sprocket is £560 it has two, even head set is £350 just a money pit really but keeps me busy lol