PR coils plus HKS 4 steps colder plugs

Threetirtyfive

Corporal
Jan 9, 2019
131
65
0
Ride
335i
Hi guys
Thought it might be interesting for the guys pushing their builds 200% over stock power or more I've been experimenting with HKS M50-HL plugs which are a direct fit in the n54. Same thread size and pitch, same plug size, smaller ceramic outer.
These are plugs for extreme tuned nissan gtrs according to their literature.

Initially my with testing, with stock coils and stock gap, I had some misfires which was disappointing as the timing was significantly cleaner. It only felt like a misfire under load and felt like only 1 or 2 cylinders.
So i thought fuck that back to 97506 and that's where i stayed for 6 months.

So later, having had some high rpm misfires at the dyno decided upon PR coils and with the same set of HKS plugs gapped to 0.5mm.
Cut a long story short 1 plug of the set of 6 was faulty. I replaced that plug, all misfires have gone and the car pulls a lot harder.

This is all I have so far rather than hard data from logging or at the dyno but it's promising enough to share, especially with how much cleaner the timing was the last time I logged. Shortly after this combo my clutch gave out so I was unable to get any logs or dyno time. But with the general rule 1 step colder for every 100bhp over stock, perhaps we can start to look at running much colder plugs in these cars than just what everyone uses with the ngk 1 or 2 steps colder.
I don't have a lot of carbon build up with these on the tip as sometimes happens if the plug is not matched to the tune {colder plugs take the heat away from the tip to the cylinder head faster vs a hot plug which should clean up timing and prevent pre ignition}


Check back and I'll provide logs and dyno results once I have a twin disc fitted.
{built n54, 19t turbos, port meth 30psi}.
 
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Milan

Sergeant
Dec 24, 2016
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jebi se
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GTRs make like 1k whp with stock plugs. 4 heat ranges colder makes no sense at all

anyway we all tried GTR plugs like 4 years ago and most of us, myself included, had horrible misfires
 

Threetirtyfive

Corporal
Jan 9, 2019
131
65
0
Ride
335i
Not sure if they ship dodgy batches, but after identifying the misfire following a plug it was straightforward to eliminate along with correct gapping.
As the rule of 1 step per 100 it's not so crazy to run colder than just 2.
The logs were sooo much cleaner.
Anyway further testing is needed.