Regap factory plugs. Go 3/10ths faster!

[steph93lx]

Pull my plugs and they were all .050" on the money. Oh well, it was still nice to get intimate with my GT and peace of mind is priceless.

Same for me all at .050". I am pretty sure the majority will get the same result. But I am happy I checked it.

Some test have been done on earlier year coyote and they have been no power difference with .045 .050 or .055" gap on N/A set up. Unless you are over .060" and get a misfire code your o.k.

Da,wind and traction make all the difference in the world.

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[Laztug]

I was thinking after I read what the OP said the gap is supposed to be it sounded low. I remember when I installed my coils on my 13, stock was around .50. And Performance Distributors recommended .52-.55 with higher power coils. Maybe it changed on the 15? So I checked the latest updated HTML user manual on the Ford owners site and this is what the gap is supposed to be stock, per Ford Not .41-.45. So if you're going to change it I would go by this unless recommended otherwise by your tuner for some reason. What was your source OP?

Bump for an informative post.

Will these 11-14 NGK spark plugs work on my 15?

NGK 6510 Iridium IX
http://www.americanmuscle.com/ngk-iridium-6510.html

(Stock temp replacement) NGK 6509 Iridium IX
___________________________________________________________________
EDIT*

http://www.partcat.com/ngk
Find out what NGK product best fits your vehicle!

I will be going with NGK 6509 Iridium IX for my 5.0

 

[dubster99]

I guess I have a project for Turkey day. Not expecting a big increase, but I would like to know that they are at least properly gapped. This is why I do all my own work instead of going to shops...I know it'll be done right.

 

[dubster99]

So I just regapped all my plugs. They were all within spec, but were not the same across all cylinders.

#1 - .052
#2 - .052
#3 - .052
#4 - .051
#5 - .050
#6 - .050
#7 - .052
#8 - .051

Not much of a difference there, and probably doesn't affect anything, but I like knowing now that they are all the same.

 

[atekido]

Not to burst your bubble about the plugs it might have helped but something else also helped ALOT.

Your first timeslip the DA was in the 400's. The second timeslip the DA was around -1200 That is Negative 1200. 400 da to a negative -1200 is a pretty big difference. that can easily account for 1-3 tenths over a 1/4 distance. still a good idea to check the gaps but you can't ignore the environmental factor. I see way to many people on these forums who don't understand why this or that makes more or runs better and doesnt even take the time to look at one of the single most important factors. That being the Density Alttitude.

 

[madweazl]

A few months back I dynod the car with Borla SType catback (2.5") and the SCT preloaded 93 octane tune. The results were 401.7hp. About a week later I went back after installing a JLT CAI and Lund tune and made 408.7hp in weather that was "about the same." After DA correction to match the 401.7hp pull (667 feet if I remember correctly), the JLT/Lund combo made 415.x (think it was 415.9 but cant remember off the top of my head). If that difference was ~2000' (no idea what the actual DA was for the original post), it would be around 432hp. Plug those numbers into an ET calculator with a 3750lb car and you get a difference of .23.

Edit: looked up the post and it was corrected to 416.99hp. ET delta would be .24 seconds.

 

[bluebeastsrt]

Not to burst your bubble about the plugs it might have helped but something else also helped ALOT.

Your first timeslip the DA was in the 400's. The second timeslip the DA was around -1200 That is Negative 1200. 400 da to a negative -1200 is a pretty big difference. that can easily account for 1-3 tenths over a 1/4 distance. still a good idea to check the gaps but you can't ignore the environmental factor. I see way to many people on these forums who don't understand why this or that makes more or runs better and doesnt even take the time to look at one of the single most important factors. That being the Density Alttitude.

Oh for Christ sakes. Of course DA matters. Do you feel smarter now. I run the fast list on this forum. I own a 95 that's a stones throw from an 8 second slip. I understand DA. I have since the 80s. If you can't understand I was trying to motivate people to check the plugs instead of blindly assuming they were gapped correctly from the factory. Maybe your the one missing the big picture. My bubble is fine thanks.

 

[Poppacapp]

Nothing wrong with pulling plugs and doublechecking the gap.

 

[Tommy V]

Lol just does not stop!!!!!.

 

[MyMilkshake...]

Is that thousandth of an inch?

What's the perfect gap? 0.041 - 0.045 (GT PP)

What cooler plugs do you guys recommend?

 

[dubster99]

Unless you're running nitrous or FI you don't need colder plugs.

 

[RSKTAKR]

Bump for an informative post.

Will these 11-14 NGK spark plugs work on my 15?

NGK 6510 Iridium IX
http://www.americanmuscle.com/ngk-iridium-6510.html

(Stock temp replacement) NGK 6509 Iridium IX
___________________________________________________________________
EDIT*

http://www.partcat.com/ngk
Find out what NGK product best fits your vehicle!

I will be going with NGK 6509 Iridium IX for my 5.0

I'm going to be spraying Nitrous and was wondering the same thing.. I am also after the 1 heat range cooler plugs. Are these the correct replacement for the 15'? I would thinks so but just wanted to make sure. Also what would the 1 heat range cooler plugs be gapped at?

 

[Braski]

So I just regapped all my plugs. They were all within spec, but were not the same across all cylinders.

#1 - .052
#2 - .052
#3 - .052
#4 - .051
#5 - .050
#6 - .050
#7 - .052
#8 - .051

Not much of a difference there, and probably doesn't affect anything, but I like knowing now that they are all the same.

Like the saying goes, "it's within ---- hair"!:lol::lol::lol:

 

[LETHAL]

Ok man your right. The car probably runs exactly the same if the gap is correct or not. Probably no science involved with that at all. Why do they even recommend gaps on spark plugs anyway if it has absolutely no effect on an engines performance???? Anyway to everyone reading this besides stoli. If you feel like your car is under performing. You should check the spark plugs. I DID and found them all to be incorrectly gapped from the factory by a large margin. After that was corrected. The idle smoothed right out and the car ran better! It's a very easy thing to do on these cars. It take all of 15 minutes! Or you can do nothing and live with it. Maybe stoli is right and the DA was 100% responsible for the increase in performance and had nothing to do with the changes in the gap I made. What if he's not right? His theory doesn't explain how my buddies car picked up 3MPH, 3 weeks ago after he received service? What do you have to lose even if it's only worth a tenth and a mile per hour? The point of this thread was to make people aware of a potential problem. Not quibble over DA. You can only try to arm people with information. Some people refuse to get off the tracks when you tell them a train is coming!:(

Feel any legit difference how it runs on the street? (Not a doubter, just curious as I meant to try this back in Oct and forgotLOL)

 

[LETHAL]

Finally got around to doing this today.

Found my factory gaps were around 0.58.

Set them to 0.45.

I can honestly say that I can feel the car pull harder toward 7k better than it used to. Esp in 2nd and 3rd.

See if I pick up noteworthy trap speed at the next track day.

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