Spark Plug questions

[FracaSHO]

I got a MyCal from LMS and I'm planning on loading a stage 4+ on my 2010 SHO. I know I should replace the spark plugs with 1 stage colder plugs and gap them to .0300  My question is does anyone know the stock heat range and gap? According to Ford's site I have motorcraft SP512, but they show SP528 for the 2011. I'm confused because I got a set of NGK LTR7IX-11 that I thought were 1 stage colder, heat range 7. But the 2013 SHO's have the SP534, which was stated on this forum that they are the same as NGK LTR6CI-8 which are heat range 6. I just want to make sure I am selecting the right plugs. Thanks.


Brad
2010 SHO with PP
Sent from my iPhone

[FracaSHO]

UPDATE ON MY RESEARCH:

I just wanted to share the info I have found on the subject of spark plugs.

2010 SHO's were outfitted with SP512 plugs.
2011-2012 with SP528
2013 with SP534

According to my research the SP528 and SP534 are re-branded NGK LTR6CI-8 and LTR6CI-9 respectively. Heat range on these plugs are 6 per NGK's site stating that the number in the middle is the heat range. It seems Ford got smart and starting using 1 stage colder plugs in 2011. I also called LMS to ask what plugs they offer as an add on to the MyCal tuner, and was told they are the Ford SP534, 1 stage colder. Also according to NGK's site, higher numbers are colder.

My conclusion:  2010 SHO's came with plugs that have a heat range of 5 from the factory. The newer plugs are 1 stage colder with a heat range of 6. And the NGK-LTR7IX-11 plugs (which have been used/suggested by members of this forum) have a heat rang of 7 making them "2" stages colder.

I know the reason for going 1 stage colder. What would be the reason to go 2 stages colder? I am leaning toward buying plugs from LMS. Costly I know, but that would ensure a proper gap by professionals using the proper tools.

DISCLAIMER:  I am in no way saying any or all of the information I provided is 100% accurate and true. The info is simply my conclusion based on my own research using manufacture sites and forums.  Please do not hesitate to correct or add additional info.




Brad
2010 SHO with PP
Sent from my iPhone

[DJE624]

I've got the SP534's coming.  Pretty sure my shop will gap them properly.  I'm writing a list of instructions.  I just hope they have that fancy tool the Tom posted.

[Tractorak]

I picked up this tool from sears http://www.sears.com/craftsman-14-leaf-ignition-gauge/p-00940801000P?prdNo=4&blockNo=4&blockType=G4

and adjusted my SP534's last night all to .030 they were all gaped around .035 - .036. I have close to 22K on my originals so it will be interesting to see their condition. I am going to swap them out this weekend. I bought the one with the point feelers because I do have a couple of Moto Guzzies that still run points.

[DJE624]

LOL  I remember point feelers!  When I change my plugs they will only have about 7500 on them.  I hope they will look pretty good.   

[crash712us]

a stage colder won't hurt but not necessary, as it wasn't a requirement when 1st tuned my car. Was only require for meth tuning.

[curry67]

if you have a 2010 do they put the 2013 plugs in when you get them replaced?

[TSS]

Yes.  I had my 2010 plugs replaced in early 2013 and the dealer used the newer SP528 plug.  FYI, absolutely no noticeable difference. No idea why they did not use SP 534.....maybe it was too early in 2013?

[mjhpadi]

Well, now I'm kinda confused with this?  According to the thread 2010's came with a range 5 plug and then Ford changed to a range 6 in 2011? And finally a range 7 in '13?  Does that me that the 2010's are OK with current range plugs or should go a step up? Sorry, but I'm just trying to get this straight.  It looks like the SP528 are cooler then the SP512's?  If the higher the number the lower the heat range is correct...now I'm really confused.  Exactly what is the recommendation for the 2010's?

[bykr]

If I'm reading this correctly the 528's and 534's are the same heat range(6).I'd just put in the 534's and call it good.

[FracaSHO]

Yes, according to my research the 528 and 534 are the same heat range, 6.

I was hoping someone could chime in and confirm the 512's heat range?  I'm deducing they are heat range 5, but have not been able to confirm.


Brad
2010 SHO with PP
Sent from my iPhone

[BiGMaC]

Yes, according to my research the 528 and 534 are the same heat range, 6.

So the obvious question I have to ask... especially since it's coming up for me... is: What is the difference in construction (and possibly function) between the 528s and the 534s ??     Is it purely fit/cosmetic?

[DJE624]

That kind of ticks me off.  I have 534's coming and I thought those were one step cooler or improved some how.  At least they are new and will be gapped the same at 30.

[Kolk1]

Ok, so I've been meaning to get around to them for awhile, but the car still ran fine. I'll probably hit 60k miles tomorrow, and I've been stage 4 93octane on a sct since about 35k miles.

Not sure if it was age, poor build quality, or me being rough on the car. But most of the electrodes were most of the way gone. Two of them were .036-.038, but the other 4 were .042-.045

I've only done a quick drive, not sure if it's a placebo effect or what, but the gas pedal seems a Hair more touchy, and full boost seems smoother.

I gapped all the new plugs to about .029-.030. They are the NGK lot number #6510, can't remember the model number off the top of my head but I think it had a 71 in it lol.

I'd suggest not waiting as long as I have if you are thinking about it. Takes less than an hour, assuming you have the correct tools.

I'll take pics of the plugs when I get home.

[Kolk1]

New plus I used were NGK LTR7IX-11