Spark Plug questions

I'd use a iridium plug either in a motorcraft sp534 or ngk don't know the part number or a Denso itv-20 I believe factory gap is .035


Sent from my iPhone using Tapatalk
 
got my cousin who works for ford picking me up the plugs with his discount. Also he is going to help install them. Its nice to have someone on the inside :) Also thinking about doing a tranny fluid change while im at it
 
I have been following this thread with interest.  According to the owners manual, the recommended gap for my 2010 is .033-.037.  I checked the manual for a 2013 SHO and found the exact same recommended gap.  I understand going to .030 if you are running extra high boost levels, meth, upgraded turbos, etc.

I am just running the 2012 version of LMS stage 4/93 octane.  I might try Torrie's tune at some point but have no intention of running meth or doing anything more exotic than what I already have.  I am going to replace my plugs with SP534s as routine maintenance.  What benefit would there be to gap them at .030 versus the recommendation of the manual?  Typically, I would expect a larger gap to be better - assuming the coils are strong enough and the boost doesn't blow out the spark.  I have no idea what my current plugs are gapped at but I have never experienced a problem with misfires or any other issues.

Thoughts?
 
LMS recommends a gap of 30 when running a tune.  That's what I did this past week.  Runs great. 
 
We all know that the SHO literally eats electrodes... I am assuming that the 3.5TT MKS is the same.  Could be a matter of reliable spark.  I also wonder if it is a detonation precaution for the timing advance and increased boost when tuned?
 
ok finished my plug replacement with the help of my cousin who works at ford. Heres the pic of the plugs after removal. Car has 53000 miles
 
Those don't look too bad to me.  What did you finally gap the new ones at?  Did you use the SP534?
 
What is the difference between the sp528 and sp534 spark plugs my cousin Said these were the ones recommended for my vehicle when he pulled up the info at ford
 
528 are platinum, 534 are iridium.  And, I think according to one chart I saw, the tips are different (that may be the materials).
 
I doubt there is any noticeable difference.  If you gapped them at 30 you should be fine.  I had 528's. I think they upgraded the material for the '13 to iridium.
 




I got my NGK  Iridium ix  LTRR71X-11 stock # 6510 in the mail today .
I plan on putting them in tomorrow evening after I pick up my SHO from the body shop in the Morning.
Any one know if there is any " special " type of gaping tool to use on iridium plugs ?
I've never used iridium plugs before and get the impression the electrode is somewhat easy to damage .
Can I just use a standard feeler gage and gap them at .030  ?


 
Night Hawk said:
This is what i use
That will work, just don't try to gap by forcing the .30 gage part of it between the electrode and collector. Use the cut out part to bend the collector in waterer direction it needs to go.
 
The proper plugs gapped correctly can help prevent spark blowout at higher (tuned) boost levels.  So in that case it would help performance. 
 
Back
Top