Why HKS Plugs?

[D-C]

I'll have to check with Jason here and get back to you. I left it on his plate with a few of our other CNC projects.

Bump

Terry sorry for my impatience but if the new spark plug tool is a few weeks away I will just put my pending order through to you guys as I mention above


Thanks

 

[Hydrajin]

@Terry@BMS how are the Denso plugs holding up? I'm getting shot plugs without tune or chip, just intake and exhaust.

 

[DaBears4Lyfe]

@Terry@BMS how are the Denso plugs holding up? I'm getting shot plugs without tune or chip, just intake and exhaust.

Mine are still holding up up 15k in

 

[Hydrajin]

Mine are still holding up up 15k in

Blew stock plug on cyl 3 (the pia cylinder to get to) they replaced it and it blew again as soon as I drove off the lot and hit it hard. Ordered 8 Denso 5347s, keeping fingers plugs are the problem an not else what. The crack in both blown plugs is definitely a heat/expansion crack. I don't see any other way the porcelain crack could have happened. My theory is heat not escaping quickly enough in cylinder 3 because the surge tank directly covers that coil only. If it blows a Denso 2 steps colder than stockst may swap cyl 4 and 3 coils to see if it's a coil issue or cylinder issue.

 

[ZyroXZ2]

Blew stock plug on cyl 3 (the pia cylinder to get to) they replaced it and it blew again as soon as I drove off the lot and hit it hard. Ordered 8 Denso 5347s, keeping fingers plugs are the problem an not else what. The crack in both blown plugs is definitely a heat/expansion crack. I don't see any other way the porcelain crack could have happened. My theory is heat not escaping quickly enough in cylinder 3 because the surge tank directly covers that coil only. If it blows a Denso 2 steps colder than stockst may swap cyl 4 and 3 coils to see if it's a coil issue or cylinder issue.

While I think you might have a coil problem, why would you "hit it hard" as you "drove off the lot"... The engine is still cold and the oil hasn't quite sheeted itself in your turbo's bearings, yet...

 

[Hydrajin]

While I think you might have a coil problem, why would you "hit it hard" as you "drove off the lot"... The engine is still cold and the oil hasn't quite sheeted itself in your turbo's bearings, yet...

Car was running for a good 30 mins before I drove off. By hard I mean reached 3500 (peak boost) not redline to shift.

 

[JDM_Man]

What should the HKS plugs be gapped to?

 

[Hydrajin]

What should the HKS plugs be gapped to?

I'd gap any plug to .025 or smaller on a turbo engine.

 

[Hydrajin]

I'd gap any plug to .025 or smaller on a turbo engine.

But don't go below .02, it may not ignite with the stinger's ignition system. I'm personally gaping mine to .024 when they arrive and testing it out for a while to see how well it works.

 

[Ek9max]

But don't go below .02, it may not ignite with the stinger's ignition system. I'm personally gaping mine to .024 when they arrive and testing it out for a while to see how well it works.

Did you get denso 5346 or 5347?

 

[Hydrajin]

Did you get denso 5346 or 5347?

Yes sir, ikh27 5347 is what I am running since my cracked plugs incident.

 

[Ek9max]

Yes sir, ikh27 5347 is what I am running since my cracked plugs incident.

What made you try then over the BMS recommended 5346?

 

[Hydrajin]

What made you try then over the BMS recommended 5346?

Experience and knowledge, 1 step colder won't make much a difference if heat is the problem, I would have gone even colder if I could cross reference a plug, I was driving 2 weeks on 5 cylinders and was pressed for time when choosing and buying. Coldest plugs I could find that would get to me quickly were the ikh27, and was lucky to find them cheap.

 

[MrSmoofy]

I'm about to order plugs, are we still recommended Denso's over anything else and should I go with the colder 5347 over the 5346

 

[Hydrajin]

I'm about to order plugs, are we still recommended Denso's over anything else and should I go with the colder 5347 over the 5346

I'd go with the colder 5347, running perfectly fine with me and no cracked plugs so far despite added ambient summer heat in the engine bay. You can also do hks but I don't see why spend more than double on the same plug lol.

 

[MrSmoofy]

I'd go with the colder 5347, running perfectly fine with me and no cracked plugs so far despite added ambient summer heat in the engine bay. You can also do hks but I don't see why spend more than double on the same plug lol.

I'm in Florida been in the 90s for the last few weeks already so colder seemed better to me too but I'm new to all this. Thanks

 

[Jays_stinger]

Yes sir, ikh27 5347 is what I am running since my cracked plugs incident.

Did you gap them or just installed them with the 0.4 specs?

How are they running now? any issues?

 

[Hydrajin]

Did you gap them or just installed them with the 0.4 specs?

How are they running now? any issues?

Gapped them to .024 as suggested here. I have have noticed serious erosion on the ground electrode for the denso in about 15000km. And had cylinder 5 porcelain crack for some reason, looks like an expansion crack like the OEMs had but it blows my mind why because these are 2 steps colder and shouldn't really crack the way the OEM plugs did. It could actually be a problem with my motor specifically because other local stinger owners have run stock plugs with jb4, intakes, and exhaust without the cracking plug problem.

 

[Toddasaurus]

Gapped them to .024 as suggested here. I have have noticed serious erosion on the ground electrode for the denso in about 15000km. And had cylinder 5 porcelain crack for some reason, looks like an expansion crack like the OEMs had but it blows my mind why because these are 2 steps colder and shouldn't really crack the way the OEM plugs did. It could actually be a problem with my motor specifically because other local stinger owners have run stock plugs with jb4, intakes, and exhaust without the cracking plug problem.

Interesting that even the Denso's have cracked on yours... I wonder what is causing it??

+1 running OEM plugs with JB4, intake, VT snorkels, secondary downpipes/midpipes, and cat-back exhaust. I bought brand new OEM plugs, regapped to 0.026, trimmed the ground strap (just for fun), and it's been running strong ever since the install (August). I pulled them a few weeks ago to check the electrodes and everything looks perfect. I really think the OEM plugs are better than many people think.

Edit: BUT - I do agree that running 1 or 2 steps colder is a good idea when significantly increasing boost (like around 20+ psi), though there is an argument to be made that something like WMI is a way around that rule. FWIW I haven't gone above map 2 (JB4) with my plugs.

 

[OriginalRobby]

So are HKS plugs the way to go then? And how long is their life expectancy?