Copper or Iridium TR6's w/ 125 wet shot?

I am replacing the COP's today with the newer "clear tops" and also going to do the plugs while I'm there. I have a NX wet kit jetted for 125 HP and was curious as to what you guys recommended.

Sam at Coastal Dyno here in Tampa, FL recommended that I gap the TR6's at .032" for the 125 shot. Sound good?
 
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hotmustang331 said:
Tim @ MPH told me to go with NGK BR7EF plugs with my turbo app. Those are a few heat ranges colder than stock....but im not sure if they are what you need. Others should know for sure.

Thank's for the reply. I do know that for a 125 shot or less, you only want to go 1 heat range colder and gap the plug tighter than normal.

While working with GM powered cars, I learned this about Iridium plugs:

Copper or Nickel plugs tend to have a bigger center electrode. Due to large surface area of the center electrode on Copper/Nickel plugs, they can actually "squash" the initial flame kernel and prevent an optimum flame front as a result. This is typically referred to as flame kernel quenching. Using a much finer center electrode, as on the Iridium's, this flame kernel quenching is significantly reduced and therefore allows a more efficient flame front resulting in more power.

Iridium center electrodes also absorb far less heat and require much less voltage in order to correctly "fire the gap". This makes your entire ignition system more efficient and creates better performance and much less chance of detonation and plug fouling.

I'm thinking good'ole coppers should be fine, but it never hurts to get a bunch of opinions from some Ford experts. I have been out of the Ford and nitrous game for a while. :)
 
.032 sounds way to tight of a gap, unless your going to have 2 sets of plugs. 1 set for the street and 1 set for the spray, if not Id do a .040 to .044 gap for all-around. I'd also go wth a cheaper "copper core" plug, because your going to "nip" a few and it will always be cheaper to re-palce some $2.00 copper plugs vs the more $$$ ones at @$5.00 each
 
RandyStinchcomb said:
.032 sounds way to tight of a gap, unless your going to have 2 sets of plugs. 1 set for the street and 1 set for the spray, if not Id do a .040 to .044 gap for all-around. I'd also go wth a cheaper "copper core" plug, because your going to "nip" a few and it will always be cheaper to re-palce some $2.00 copper plugs vs the more $$$ ones at @$5.00 each

Thanks for the advice Randy. .032 sounded pretty tight to me as well, but like I said, I am not all that familar with the mod motors. I got them all in at .033 right now and it pulls hard. But, I will pull them and open them to .040 and see how she runs on and off the bottle.

Any opinions on COP replacements? Everybody is telling me the OEM Motorsports are probably the best bet. Is there truth to that?
 
I talked to another Mustang "specialty" shop, 2nd Street Performance (they build Pro 5.0 cars), and they also liked the .032" on the TR6's for daily drivers w/ a 125 shot. Maybe I'll keep them at .033" for now and go see how it dyno's.
 
LaserRed01GT said:
Any opinions on COP replacements? Everybody is telling me the OEM Motorsports are probably the best bet. Is there truth to that?

For right now, Motorcraft COP replacements will be your best bet. There isn't a whole lot of aftermarket ignition options for the 99+ 4.6s... the motorcrafts tend to offer the best performance and reliability. If you end up needing more spark down the road, you can look into a kenne bell boost-a-spark, or plasma booster.
 
RandyStinchcomb said:
.032 sounds way to tight of a gap, unless your going to have 2 sets of plugs. 1 set for the street and 1 set for the spray, if not Id do a .040 to .044 gap for all-around. I'd also go wth a cheaper "copper core" plug, because your going to "nip" a few and it will always be cheaper to re-palce some $2.00 copper plugs vs the more $$$ ones at @$5.00 each
HOLY $hit Every time I say I run my ngk tr6's at .040 for all around street and nitrous use I get bashed on.

But for original poster I'd go copper and if it'll be the only set open the gap a lil if memory serves me they are pregapped at .035.
 
BooWFO said:
HOLY $hit Every time I say I run my ngk tr6's at .040 for all around street and nitrous use I get bashed on.

But for original poster I'd go copper and if it'll be the only set open the gap a lil if memory serves me they are pregapped at .035.



ok, here is the thing about the sparkplugs you all are using. there are designed for a large gap, .050 or more. now when you close that gap below .040 you DO NOT have a flat gap across the center electrode because the ground strap is taller for the wide gap plugs, so it may appear to be .032 or .038 but if you look at the rear of the ground strap you'll see it's "humped up" (for lack of a better term) so a .040 to .044 gap will give you a pretty close to flat gap across the center electrode and ground strap and a better more uniformed spark and the factory ignition system will have NO problem wth it, (S/C or Turbo cars are a different animal). also that small gap(.032 to .038) on a Nytrous car when driven on the street will suffer from poor performance and poor gas milage. Oh and NEVER use Platinums in a power adder engine for any reason, I dont even like plats on the street, seen to many problems wth them
 
RandyStinchcomb said:
ok, here is the thing about the sparkplugs you all are using. there are designed for a large gap, .050 or more. now when you close that gap below .040 you DO NOT have a flat gap across the center electrode because the ground strap is taller for the wide gap plugs, so it may appear to be .032 or .038 but if you look at the rear of the ground strap you'll see it's "humped up" (for lack of a better term) so a .040 to .044 gap will give you a pretty close to flat gap across the center electrode and ground strap and a better more uniformed spark and the factory ignition system will have NO problem wth it, (S/C or Turbo cars are a different animal). also that small gap(.032 to .038) on a Nytrous car when driven on the street will suffer from poor performance and poor gas milage. Oh and NEVER use Platinums in a power adder engine for any reason, I dont even like plats on the street, seen to many problems wth them

I appreciate your opinion, but I respectfully disagree.:) Colder plugs will usually come out of the box gapped much tighter than the stock plug designed for the same motor. In this case, these TR6's (4177's) all came out of the box at .033". As you can see below, the TR6's come out of the box with a relatively parallel relationship between the bottom of the ground electrode and the top of the center electrode. If anything, there is maybe a .001"-.003" larger opening at the end of the ground electrode. So tightening them up to .032" would make them just about perfect.

But in all honesty, when you're talking about a center electrode with a v-groove manufactured into it like these "V-Power" NGK plugs, whether or not the ground electrode is parallel to the center electrode is a moot point. The spark is very concise and only jumps off of a fraction of the surface.

View attachment 436072

.050" or more even on a factory plug is way to much, especially on a 1 heat range colder plug. I believe the factory recommended gap for the stock Motorcraft platinums is .045. Generally speaking, when you go 1 heat range colder you also go 1/100 tighter and that is why I believe NGK has their TR6's gapped at .033 out of the box.
 
colder plugs do not always come wth a tighter gap, maybe NGK's do as they put a cardboard tube over the bottom of the plug for packaging but other companys do not do that. also the factory gap is .052 to .054 and most other plugs are of the wide gap design, maybe those NGK's in the picture are different but I know most of the other plug companys plugs do not gap-out correctly and always re-check your plug gap before installing
 
RandyStinchcomb said:
George, don't jump the gun just yet. this thread was started for a Nytrous car and your's being blown is a whole nother topic.

They had a hump to them. I just thought them being gapped that small from the factory was crazy. I have no idea where to gap plugs for nitrous. I wasn't taking sides I was just making an observation about the plugs I just picked up.:D