Spark Plug? 1997 Cobra S-Trim (20lb pulley) non-intercooled, 4.10

[98Bird]

1997 Cobra S-Trim (20 lb pulley) non-intercooled, 4.10 gears.

Plug in there now, NGK TR6 (V Power). Advanced Auto Website says this ain't the right plug! It's been in there for years. Had motor work by previous owner, so I dunno.

Advanced Auto says to use NGK TR55

And what should the PLUG GAP be for this setup?

Thanks for any help.

 

[01yellercobra]

The stock plug is for an N/A set up. I believe the TR6 is one heat range cooler than stock. Which is good for blown applications. Stick with what's in there if you're not having problems. The car is no longer stock. You can't go by what the counter jockeys computer says anymore.

What fuel are you running? 20psi is a lot for a non-intercooler set up. Unless you're running meth.

I ran my centri set up at .030" gap.

 

[98Bird]

The stock plug is for an N/A set up. I believe the TR6 is one heat range cooler than stock. Which is good for blown applications. Stick with what's in there if you're not having problems. The car is no longer stock. You can't go by what the counter jockeys computer says anymore.

What fuel are you running? 20psi is a lot for a non-intercooler set up. Unless you're running meth.

I ran my centri set up at .030" gap.

Thanks.

 

[9397SVTs]

That plug does not look good at all.

Do all of them look like that?

Are you running leaded race gas?

You could try another set of TR6's with a gap around .020.

I would probably use a BR7/TR7 gapped at .020.

 

[01yellercobra]

That plug does not look good at all.

Do all of them look like that?

Are you running leaded race gas?

You could try another set of TR6's with a gap around .020.

I would probably use a BR7/TR7 gapped at .020.

That's really tight. I doubt he needs to go that tight. I ran .030" with my F1A at 19psi. Never had blow out. With my current sent up I'm at .028" at 18psi. Stepping down a heat range probably wouldn't be a bad idea though given the lack of intercooling.

That plug is just really worn out. Probably had some misfiring going with that gap.

 

[9397SVTs]

It's more than just worn. The center electrode appears to have melted. Was it overheated due to the spark plug heat range, lean AFR, or improper ignition timing?

It also appears to have some speckling on the insulator.

I would get it on a dyno and start diagnosing/checking thing out.

 

[98Bird]

Thanks for all the help.