Spark Plug Gap

[Gmoney721]

What are you guys gapping your plugs to?

 

[Sputter]

I am sure you will get many answers to this question. It depends! Turbo, Nitrous, ignition, compression, fuel? Close for cylinder pressure, open for stronger ignition. Usually something you need to set for your combination.

 

[Boosted Cycle Perf]

Being this is the turbo I'm going to assume turbo...

Stock ignition coils run the gaps at .018. You can go bigger if you have a sim, or some other type of ignition amplifier.

 

[Gmoney721]

Ok thanks for the replies. I'm running mine at .018 and I'm having a dentonating problem at 9k on the dyno. Changed to new set of plugs and first run went perfect. Every run after that the problem came back. Trying to elimate what the problem could be

 

[Gmoney721]

Yes turbo application

 

[Sputter]

What do the plugs look like? Lean condition can do that. So can a rich mixture but that would be more evident.

 

[Gmoney721]

 

[Sputter]

What and how old is your fuel? You can get a magnifying glass and check inside around insulator but at this point I would say add some fuel. How much time, just 1 pull on them? Maybe back out some timing too? I would add some fuel then timing and not pull hard until then.

 

[OZBooster]

What do you call detonation, ? plug gap would make a difference with a miss, but plug heat range is one of the things to consider if you have detonation increasing on multiple dyno runs
first would be the relationship between a/f and ign timing

 

[Kevin Jones]

Is it me or does that one plug look a different shade then the rest? Have you ensured that the injectors were cleaned? I would send them off to MPS and have em sonic cleaned for peace of mind in addition to the other suggestions.

 

[B n s racing]

Second plug from the left is darker

 

[Kevin Jones]

What conditions would cause a too rich fuel mixture to detonate? Just asking because I would think it would bog the motor out before anything adverse other than carbon fouling.

 

[Boosted Cycle Perf]

What's the afr when you're "detonating"?

Looks to me like it's pig rich. Getting one pull before it breaks up on the next backs that up.

 

[Kevin Jones]

That's something everybody but Rob missed. He is terming "detonating" as something that probably is not what is really happening. Something is happening on that dyno but it isn't detonating. His plugs actually look kind of like what mine looked like after we had a problem with the sfi map and we couldn't take out enough fuel. It was actually a lack of knowledge on the microtech but essentially the pulls would be so rich it would go to about 10 afr and bog.

 

[Sputter]

I believe all are just attempting to assist the OP with items that require more accurate information to begin a diagnosis. Many times there may be more than one problem that require attention before the other is apparent. Without pertinent information that is accurate all are just speculation. Maybe someone may get it but accurate information is key. Without it a goose chase entails.