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Discussion Starter · #1 ·
I have a set of Denso IT20s in and they were installed before I ever bought this truck... Jim @ JDM told me he could tell by the sound of it on the dyno and with his knowledge, I belive him... that they need to be regapped... his guess was I was well over .04 and said I need to be about .034

so Im gonna get a new set of plugs and do this very soon, as soon as I get the plugs...

but my question is... what all problems can this cause?

loss of power? mad gas mileage? funny idle? what???

im just curious... i had never thought about checking the gap since Iv had the truck, so im wondering once its right, what kind of improvements I might expect...
 

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I'm interested in the reply as well, as anything spark plug related...gapping, ranges, etc... I tend to get a glazed over look of complete idiocy. :shock:
 

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Opening the spark plug gap increases the spark kernel size. This creates a more efficient burn. But opening the gap to wide would over work the coils, because there’s not enough energy to cross the gap, causing a miss-fire. Of course, it would all depend on the amount of boost you’re running. If you gap them to close the plug can’t clean itself, causing a fouled plug.
 

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You know my take on this Scott, (I DO NOT like a gap too small)
As for an answer to your question, first read this, I just found this on a post over on F-150

Originally posted by 1BADTK
Two things, BR7EF's are way to cold a plug to run everyday and they will make the truck buck and miss really bad, and a stock Lightning will miss at idle. Do not close the gap on whatever plug you use if u are not running any increased boost. to close will cause a miss also. Gap at .042 for stock boost, and reduce that .001 per extra pound of boost over stock. :thumbsup:
Why am I asking you to read this ? Because I wanted you to notice the Gap
(.042) I think stock may even be bigger ???
We start out with a large Gap, WHY ??? Because that’s the way they're designed to work CORRECT.

Now to understand why EVERYONE tells you to gap smaller, and in fact gap smaller themselves. As you add more Pulley and Boost and Power, you are also adding more Cylinder Pressure, and at some point, IT MIGHT get so strong that it can actually cause "Spark Blow Out", meaning the Gap is too large and the nice spark that use to jump across from tip to center, is now in the middle of a hurricane. So the band-aid fix is to simply make the gap closer, so the spark doesn't have to jump as far anymore, hence the problem is fixed. FIXED WRONG and it'll work, but you just took power and technology away from the design.

My ignition will fire CORRECTLY right up to a Gap of 1.00,
I currently run .038 -.040 gap, and that’s with major boost 15-17 lbs, plus
75 HP of Nitrous. Why can I get away with it (I know you know the answer Bro, but some may not) because I did it right and increased the spark with a Multi Spark Ignition, NOT HID THE SPARK SO THE STORM CAN'T GET IT.

A little test,
stand 3 inches from a wall and run into it,
then stand 3 feet from a wall and run into it
WHICH GIVES YOU A BETTER BANG [smilie=xxrotflmao.gif]

WHAT EXACT GAP DO YOU HAVE RIGHT NOW ???
WHAT GAPS HAVE YOU TRIED IN THE PAST ???
AND HOW MUCH BOOST ARE YOU SEEING ???

BTW Scott,
If you read the whole Post, you'll see EVERYONE is having prob's with BR7's on the street unless they are heavily moded
I would give serious thought on NOT USING THEM BRO

http://f150online.com/forums/showthread.php?s=dc0299901aeb4708a0ce2634e668a811&threadid=169426
 

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Hey Rob, How many times have you done that run into the wall test....... :twisted:
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.couldn't resist :D
 

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Discussion Starter · #6 ·
Well I bought the truck about 8-9 months ago and it already had a 4lb, chip and IT20s...

iv added a few things, like ported blower, SCT and dyno tune from JDM, efan, etc

I need to get a new autometer boost guage, because I think mine is malfunctioning... i can tap on it and watch it jump 1-2 lbs of boost just by tapping it... right now at WOT i see about 12lbs boost which cant be correct. I figure with the 4lb and ported blower I "SHOULD" be about 14+

with all the mods iv done since i bought the truck, changing the plugs WASNT one of them. I pulled a couple and checked them and saw they looked ok, so I havent changed... but never thought to check the gap...

but my tuner, JDM told me to gap it at .034 so thats what im gonna do.... but I am curious to take these out and just see where they are. when Jim dynod my truck, without a flinch, he immediatly knew my plugs were a problem by the sound and the jerky dyno chart... he said he thinks they are well above .04

im gonna be installing my new efan and new plugs probably one day next week (this weekend Im busy) I currently have a set of BR7s so I had thought of just using them... but doesnt seem like a good idea from what everyone says...
 

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Maybe the port job lost a 1-2psi somewhere??I've seen a few latley that lost a couple psi due to a port job OR incorrect sealing of the blower/intake! Maybe aLeaky boost dump valve??
 

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Discussion Starter · #9 ·
holly chit!!!

my buddy just called (one doing the plugs for me)

the first one was at .046..... but that was the best one.... some were in .05 and .06 range!!!!

he said only problem im having now is TRACTION... cant keep it from spinning under 30mph

whoohoooo
 
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