Spark Plugs AGAIN!

[mjchip]

Hi Folks,

It's me again, the bookworm. I've been hearing a lot about people with '03 Cobras who have changed their plugs to NGK TR-6's having increased spark blowout in the upper RPM range. Our test car has been having the same issue SO I've been doing a little research and this is what I found:

http://www.crownvic.net/tech/sp_101.html

In a nutshell, the stock plugs that came in our '03 Cobra were: AGSF12FM1 and guess what they are:

FINE ELECTRODE PLATINUM-IRIDIUM ALLOY plugs

Here is a picture comparison of the two plugs:

We might have taken a step backwards by going to the TR-6 plugs. Thoughts?

MJ

 

[f4sfed]

Are you suggesting sticking with the type, just a colder one? Or keeping what came stock?

 

[JB]

define "stock plugs".....

as Jim Vaccaro was the first to point out, ours have come with 3 different heat ranges: AGSF12FM1, AGSF22FM1 & AGSF32FM1

mine was built sept 9th and had 22's

 

[mjchip]

Originally posted by f4sfed
Are you suggesting sticking with the type, just a colder one? Or keeping what came stock?

Well, we're about to up the boost again AND spray a 100hp shot of nitrous (dry) so.....we're going back to the AGSF12FM1 plugs because they are one step colder than the TR-6 plugs. If you want to stay with the copper plugs and you need two steps colder, I guess you can go with the NGK BPR7EFS plugs.

MJ

 

[f4sfed]

What's the TR6 equivalent?

 

[mjchip]

Re: define "stock plugs".....

Originally posted by JB
as Jim Vaccaro was the first to point out, ours have come with 3 different heat ranges: AGSF12FM1, AGSF22FM1 & AGSF32FM1

mine was built sept 9th and had 22's

Yes, correct BUT I think the important point is that they all have the new platinum/iridium alloy center electrode. Take a look at the picture about and you can see that the center electrode is MUCH finer. That will give you a higher intensity spark which will be harder to blow-out and will allow you to run a larger gap thereby increasing the size of the flame kernel which exposes more of the mixture to the flame.....yada, yada, yada.

MJ:read:

 

[mjchip]

Originally posted by f4sfed
What's the TR6 equivalent?

If you are talking about heat range I guess that it would be AGSF22FM1 (if that's a good part number).

MJ

 

[JB]

I do see what you're saying Mark but weren't some people having blowout problems with the stock ones?

might it be as simple as tightening up the gap on the Motorcrafts to get good results with them?

I think my underhood sticker says .039-.043

I didn't know they were iridium but I did like the look of the electrode when I changed mine out for TR6's

f4sfed: yes, I do believe the TR6 is a direct replacement for AGSF22FM1

 

[mjchip]

Originally posted by JB
I do see what you're saying Mark but weren't some people having blowout problems with the stock ones?

might it be as simple as tightening up the gap on the Motorcrafts to get good results with them?

I think my underhood sticker says .039-.043

I didn't know they were iridium but I did like the look of the electrode when I changed mine out for TR6's

f4sfed: yes, I do believe the TR6 is a direct replacement for AGSF22FM1

The sticker under my hood says: 0.042-0.046" gap

Since we're going to be running 16-17psi next week, we're going to close up the gap to 0.038" and stick with the stock heat range (AGSF12FM1). What do you think?

MJ

 

[JB]

hmmm....

I may very well be wrong on what my sticker says...I'll have to check it later but I'm wondering if the specified gap would vary based on the heat range that was put in the car?

you asked what I think of your dyno plans and all I can say is that I'm grateful for guys like you who are able to do this kind of testing and share the results. I haven't even got mine on a dyno yet, although I'm probably going to brave the salty roads in Jan to get a baseline done.


EDIT: yeah, I was wrong, mine says .042 - .046 also

 

[f4sfed]

Originally posted by mjchip
The sticker under my hood says: 0.042-0.046" gap

Since we're going to be running 16-17psi next week, we're going to close up the gap to 0.038" and stick with the stock heat range (AGSF12FM1). What do you think?

MJ

With you runnin' the psi up that high, why would you not run a colder than stock plug?

 

[mjchip]

Originally posted by f4sfed
With you runnin' the psi up that high, why would you not run a colder than stock plug?

The AGSF12FM1 plugs ARE one-step colder than the TR-6 plugs. A 2001 Mustang and GT both come with AWSF32 plugs. They are 2 heat ranges hotter than the stock plugs that came in my Cobra.

I don't like the idea of going any colder than -12 heat range plugs (equivalent to -7 heat range from NGK).

MJ

 

[f4sfed]

Originally posted by mjchip
The AGSF12FM1 plugs ARE one-step colder than the TR-6 plugs. A 2001 Mustang and GT both come with AWSF32 plugs. They are 2 heat ranges hotter than the stock plugs that came in my Cobra.

I don't like the idea of going any colder than -12 heat range plugs (equivalent to -7 heat range from NGK).

MJ

Okay, THANKS! :thumbsup:

Good luck on your 16-17 psi quest!

 

[03DOHC]

Originally posted by mjchip
Well, we're about to up the boost again AND spray a 100hp shot of nitrous (dry)

:thumbsup: I like the sound of this idea!:beer:

 

[mjchip]

Originally posted by 03DOHC
:thumbsup: I like the sound of this idea!:beer:

Yeah, me too! The goal is a safe 500rwhp/525rwtq off the juice and a *SAFE* 550rwhp/600rwtq with a 100-shot.

- Finishing up the design for Zone-5's nitrous controller...
- NX EFI kit coming next week
- Lower pulley and 55lb/hr injectors in early January

:beer:

MJ

 

[03DOHC]

Originally posted by mjchip
Yeah, me too! The goal is a safe 500rwhp/525rwtq off the juice and a *SAFE* 550rwhp/600rwtq with a 100-shot.

- Finishing up the design for Zone-5's nitrous controller...
- NX EFI kit coming next week
- Lower pulley and 55lb/hr injectors in early January

:beer:

MJ

Sounds good!:beer:

 

[black03]

I wonder if MR. Terry Reals from South Florida Pulley HQ has some input for us on this topic. Terry where ya at??????Black03

 

[ygohome]

Re: define "stock plugs".....

Originally posted by JB
as Jim Vaccaro was the first to point out, ours have come with 3 different heat ranges: AGSF12FM1, AGSF22FM1 & AGSF32FM1

mine was built sept 9th and had 22's

Hi

I'm finally considering swapping out the stock plugs for some NGK TR6 plugs that I've had sitting around for awhile.

I've been noticing lately that my car stumbles when it is in full boost at around 13lbs. Is this a symptom of spark blowout? I'm hopeing that it is. It stumbles almost like it is not getting any gas.

Also, wondering about the plugs I have chosen to replace the stock ones...

If when I look at the stock plugs and they are the AGSF22FM1 then the TR6 plugs would be the same heat range I think.

If the stock plugs are AGSF12FM1 then the TR6 plugs would be 1 step hotter in heat range?

and if the stock plugs are AGSF32FM1 then the TR6 would be 1 step cooler?

I would want to go at least one step colder, correct? So unless my stock plugs are AGSF32FM1, I shouldn't use the TR6 plugs since they would be the same heat range or higher. Correct?

Thanks,

Ben

:beer:

 

[ygohome]

ttt

does my post make sense about what I'm asking?

I basically need to know if the symptoms I've described is from spark blowout.

my other questions were about which plugs to use to fix the prob.

Thanks

:beer:

 

[Jim Vaccaro]

With 13lbs boost and NGK's tr6's gapped at 35 i had no spark blowout and car ran good.Gapped at 40 i had spark blowout.
I changed to Denso IT20 and gapped at 38 the noticable difference i found was a better idlewith the Denso's
With more boost i'd use a IT22..
that is my experiance with NGK and Denso.


jim v.