New recommended spark plug

[bamsho]

Well since FMC discontinued the SP542 plugs,  I thought the SP578 was the correct one, since the number supercedes the SP542.  Come to find out that I should running M-12405-35T.  Which is basically the plugs for the FORD GT with the EcoBoost motor.  From what I was told that the 542s where fouling out. 

I'll see how the 578s working for now, then switch over.  The 578s are colder than the 534s I was running.

Oh here are the 534s I pulled out, I put new plugs in when I switched tuners.  I had some gap growth of .007.  Plugs where gapped at .026.  I had the same growth when running Livernois tunes. 

First pic is cylinders 1, 2, 3. Second is cylinders 4, 5, 6.


Yes I was told I didn't drive my car very angrily.  Haha

 

[StealBlueSHO]

https://performanceparts.ford.com/part/M-12405-35T

 

[Dxlnt1]

Any update on a verdict on these plugs? I am switching tuners to AJP. So I figure since I am also due I will change ALL fluids and replace plugs.

Also was or did the MSD coils make any improvements?

 

[TopherSho]

Any update on a verdict on these plugs? I am switching tuners to AJP. So I figure since I am also due I will change ALL fluids and replace plugs.

Also was or did the MSD coils make any improvements?

I swapped them in,  and for some reason I cannot explain lost a bunch of spark (3-4 points) until i reset the KAM/ECU.  Now that the inexplicable weirdness is solved they have been functionally the same for 60 days.

I plan on pulling the front 3 plugs after my road trip and will report on fouling,  but i suspect fords got this right on the money with the new tip shape.. just hope the don't get to hot at the tip and crack/break the ceramic.

 

[Dxlnt1]

Any update on a verdict on these plugs? I am switching tuners to AJP. So I figure since I am also due I will change ALL fluids and replace plugs.

Also was or did the MSD coils make any improvements?

I swapped them in,  and for some reason I cannot explain lost a bunch of spark (3-4 points) until i reset the KAM/ECU.  Now that the inexplicable weirdness is solved they have been functionally the same for 60 days.

I plan on pulling the front 3 plugs after my road trip and will report on fouling,  but i suspect fords got this right on the money with the new tip shape.. just hope the don't get to hot at the tip and crack/break the ceramic.

Sounds good. I ordered a set for $5 I think from Summit. Will install and load new new tune/tuner. Ironically, one of the thing AJP (Brad) sent me was to reset the KAM/ECU lol.

Did you install the MSD coils?

 

[TopherSho]

I did indeed.  I think it is why my last set of plugs lasted longer, hotter tip.