I live at sea level. Not that I couldn't see myself ever going high altitude, it would be rare at best.

Say I had a fresh tune with good electronics parts, brass terminals, good wires, etc. I'm pretty stocj. I have the mopar computer and some roller rockers, stock cam....

Now if I put in a Screamin Demon high voltage coil with something like the suggested IZFR6K13 NGK Iridium plugs gapped to 0.058", would it be zero performance gains expected at sea level for normal around town driving?

Nothing at all? Not even better mileage? I could get the whole thing going on for like $150.

Not worth it until I'm for sure going high altitude?

What do you think?


https://dodgeforum.com/forum/2nd-gen...and-plugs.html

 

The stock ignition system is pretty stout. I don't think there are really any gains to be had from a higher output coil, and the rare-earth plugs are more about longevity, than anything else. For your normal day to day driving, I doubt you would see any difference at all, and it may actually CAUSE problems..... as they trucks are notorious for not getting along well with the fancy plugs.....

 

Thanks for the reply HeyYou. I'm still running a completely stock ignition and haven't noticed any problem at all. The thing that really caught my eye is UnregisterdUser's use of the 0.058" spark gap. That's a pretty big gap, isn't it? I'm not saying your wrong at all because everyone always says exactly what you are saying. It just rubs the wrong way or something to have nearly double the size of the spark flame happening in there and that doesn't change how it performs.. A sign the engineers really did have it optimized . I'll probably ask again in another five years after I forgot we had this conversation.

 

All the spark plug is doing is igniting the mixture. Sure, the HUGE gap will certainly do a 'better' job of it, but, I think most of the benefit is going to come with not having to change plugs as often. If it improves efficiency, or power output, I seriously doubt it is going to be anything measurable, and certainly not anything you will feel.

 

Makes sense man. Thanks for talking me off my ledge again.

 

All that said.... I do have to say, I LOVED my MSD box on my Formula...... multi-spark below 3K RPM...... it DRAMATICALLY smoothed the idle, and throttle response below 3K........ but, it sure munched up ignition parts fast......

 

the larger gap requires a larger output from the ignition coil. this can be seen and measured will an ocilloscope trace of the firing line and spark line. the coil will work harder but if your not going thru coils... or misfiring at high rpms you won't notice the difference

 

I second the MSD6A box! I have one on my 78 power wagon and it made a big difference. Not so much on ignition parts though. I have heard people that put them on the second gens with no ill effects. Get some long lasting plugs and the only thing you may have to replace more often is a cap&rotor. But i think it would be worth it in the long run.

 

Since I'm not a ninja, I'd rather replace as few distributor caps as possible. Sounds convincing enough for me to keep it stock. It doesn't idle that rough,,,haha

The sad thing is I've been through all this before and apparently forgot. HeyYou's story reminds me of an old race bike I put the high voltage coil and accompanying expensive spark plug wire on and it would idle and started slightly better but I couldn't detect any performance increase otherwise.

 

One thing you need to realize is the MSD6A fires 6 times as the stock(and most other ignitions)only fire ounce. I actually bench tested one and it's faster than the eye can catch it but you can see multiple sparks when it fires.