Anyone using Motorcraft AGSF12FM1?

[me32]

Maybe you did. I just looked at my stockers and they are MC SP405, (AGSF22FM1F4).
They are also listed as the stock plug for ALL GT500's.

I just LOVE spirited spark plug discussions!

Well I guess being a 2008 built in 2007 they were in a rush cause I have the AGSF32M plugs that came out of my gt500 when I swap blowers. Any way I've tried both the BR7EF Ngk an to behonest for my setup the TR6 run better for me. Maybe its the E85 an I run my gap at .025. So sorry if I gave wrong info I was basing it out the plugs that came out of my car.

 

[me32]

32 is the stock N/A Mach1/Cobra/GT plug, the Terminator and GT500 should have 22's

Well early 2003 cobras came with the 32 aswell somewhere down the line they change to the 22. It's a hit an miss what plugs you got stock on the 2003-04 cobras. Crazy ain't it.

 

[mullens]

Well I guess being a 2008 built in 2007 they were in a rush cause I have the AGSF32M plugs that came out of my gt500 when I swap blowers. Any way I've tried both the BR7EF Ngk an to behonest for my setup the TR6 run better for me. Maybe its the E85 an I run my gap at .025. So sorry if I gave wrong info I was basing it out the plugs that came out of my car.

That must be an awesome set-up. What's E-85, 108 octane?

 

[me32]

That must be an awesome set-up. What's E-85, 108 octane?

Thanks its pretty nice being able to run 22 degrees of timing on the street with E85. It's around 105 give or take. Some times pumps have given as high as E92-93 so I'm guessing that's about 108 octane. But I don't add timming for it so its running on the safer side.

 

[Slabo]

Rule of thumb is to go 1 step colder with every 75-100hp increase. We have a big problem with detonation here in 91-only-Nevada so I want to keep those cylinders as cool as possible.

From NGK's site:
"An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as a turbo, supercharger, increase compression, timing changes, use of alternate racing fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature and may necessitate a colder plug. A rule of thumb is, one heat range colder per modification or one heat range colder for every 75–100hp you increase. In identical spark plug types, the difference from one full heat range to the next is the ability to remove 70°C to 100°C from the combustion chamber. "

I do believe NGK heat range 6 is the stock heat range for our engines (hate to disagree me32). Here are my reasons:

-NGK lists the TR6 and its variants as the stock replacement for the GT500.
-Motorcraft 22 heat range (stock) cross references to NGK 6 heat range, while MC 12 heat range (as in the AGSF12M) crosses to NGK heat range 7.

If someone can show me some documentation contrary to this, I'd be willing to listen.

Thanks mullens. How much boost are you running? What gap are you going to use with the AGSF12M's?

 

[mullens]

Thanks mullens. How much boost are you running? What gap are you going to use with the AGSF12M's?

15psi TVS. I'm going to try .035 per DaFreak suggestion.

 

[Slabo]

15psi TVS. I'm going to try .035 per DaFreak suggestion.

Cool. I am also a pullied TVS. Let us know how it goes.

 

[DaFreak]

Reporting back on this: With the .035 gap I have never experienced any high rpm misses or hesitation issues. Also, in review of recent data logs the car is running better than ever. I also pulled the plugs and checked and they look perfect. Staying with .035 for now.

 

[mullens]

That's great. The trick is to keep the gap as large as possible while preventing blow out. I think .035 is the perfect compromise.

 

[mullens]

Cool. I am also a pullied TVS. Let us know how it goes.

Just be careful gapping platinum plugs. The manufacturers of precious metal plugs suggest you don't gap them because the electrode on platinum and iridium are so brittle. You have to use a special tool to open the gap that doesn't touch the electrode. I used to gap copper plugs by prying them with a screwdriver.

 

[me32]

Just be careful gapping platinum plugs. The manufacturers of precious metal plugs suggest you don't gap them because the electrode on platinum and iridium are so brittle. You have to use a special tool to open the gap that doesn't touch the electrode. I used to gap copper plugs by prying them with a screwdriver.

I know this is an old thread but what are you using to gap your platinum plugs?

 

[VNMOUS1]

I know this is an old thread but what are you using to gap your platinum plugs?

035 to 17-18psi.
I run mine at 026 at 21 psi.

Bj

 

[54First]

I know this is an old thread but what are you using to gap your platinum plugs?

If you mean what tool, I use one of those round tools with round wire gap gauges around the outside. They usually also have two or four slots to slide over the ground strap to bend them one way or the other. On my first plug I used my trusty old gapper/plier tool. Goodbye electrode. Lesson learned.

Steve

 

[me32]

If you mean what tool, I use one of those round tools with round wire gap gauges around the outside. They usually also have two or four slots to slide over the ground strap to bend them one way or the other. On my first plug I used my trusty old gapper/plier tool. Goodbye electrode. Lesson learned.

Steve

That's what I was looking for the tool used. For copper plugs I have used to round coin like slider tool followed with the round wire type to double check the propper gap. But was affraid I would break the tip on the fine wire platinum plug.

 

[enormous]

I'm running the M AGSF12FM1 gapped at .035 @18.5 boost, 94 Octane and 13 TVS w/ 2.396 pulley on a 08 Shelby and have no issues to 6,500 RPM.

 

[54First]

That's what I was looking for the tool used. For copper plugs I have used to round coin like slider tool followed with the round wire type to double check the propper gap. But was affraid I would break the tip on the fine wire platinum plug.

Forget the coin like slider tool and be gentle with the wire gauge. Use it for gap check only, not to actually widen the gap. Use the slots for adjustments.

Steve

 

[1320 Junkie]

Just threw a set in my car gapped @ .028 figured I should drop down from my stock 22's lol.

 

[Red-GT500]

I have been using TR6's for a while at .035 and 17psi with no issues. I tried the plugs the OP mentioned but kept getting spark blow out or back fires at higher RPMs. I have had a set of TR7's sitting in my garage and not sure if I should try them out. Anyone have a starting point for TR7's? I was thinking of trying them at .032 but not sure if that's to small of a gap. I'm on 91 octane, I average around 15-17 degrees of timing at WOT and AFR is steady at 11.2-1 with no spikes or dips.

I've also heard the TR7's are a non resistor type but not sure what the difference is other than possible radio interference.

 

[me32]

Forget the coin like slider tool and be gentle with the wire gauge. Use it for gap check only, not to actually widen the gap. Use the slots for adjustments.

Steve

Thanks for the heads up.

 

[YELL03]

I just bought a 2013 TVS Supercharger with stock pulley for my 2011 GT500.

I also ordered a set of Motorcraft AGSF12FM1 plus, I will gap them at 0.035.

Is that the correct plug or is it too cold?