Davis Screaming Demon Ignition Coil

[FlyinPurplePeopleEater]

Just sold another one of my cars and figured I'd give my 2004 PT Cruiser GT an ignition tune up since I have no idea when it got one last and it has a little bit of a rough idle I'm hoping to clear out.

I've done some digging on the forums and couldn't find much on the Davis ignition coil other than talk about plug gap. Anyone have any experience with these Davis ignition coils? Compared to MSD coils Davis outputs 45k volts as opposed to 36k. I know people say to just leave the stock Mopar coil on there but I figure it can't hurt to do all new plugs, wires, and coil in hopes of having a smoother idle.

Any tips or recommendations welcome, curious on the Davis coil as I've never used them but I've been happy with my MSD products.

[ptcruisersteve]

I would suggest checking all your vacuum lines including the one going to the brake booster. Check for cracks and pin hole leaks.

[rob342]

If a stock coil draws 1 amp per 1k rpm, it would be safe to assume a coil with twice the power would draw twice the power. It gets its power from those three little wires that feed it. You may end up taxing other components over time and you'd never even think that was a contributing factor.

Another thing to think about is wider gaps and stronger spark energy will erode the plugs electrode faster.

Things like "more volts" are great for advertisements, but It's not like you're going to go bragging your coil has more volts at a car show. If you like MSD I'd recommend you just stick with them, as it's already overkill.

Not a mechanic, but I'm pretty good with electronics. I dug into this recently because my wide gaps were wearing out my cap and rotor too fast on my mustang. Seemed I was replacing them with every oil change

[NitroPT]

You should do what you feel best suits your personal taste ?

As for a direct replacement coil all are pretty much the same as far as true out put energy goes. Some have better quality components like better corrosion resistant parts.

I personally choose to use the MSD. It is RED and has brass terminals.

As for voltage peak output capability and coils, most information are advertising aids to sell you on their product. The Voltage output is a very small part of what a coil does. In the performance world we tend to visit the rise time charts of any transformer.





Oscilloscopes are wonderful to use.

[FlyinPurplePeopleEater]

I do like the red color of MSD, if I remember right for the color to HP conversion red is about 50 extra HP.

Now only if it was red and had flames on it I would buy two for my car.

I wasn't too sure how the volts affect actual performance and kind of guessed it was more of an advertisement thing than anything else.

I will have to look into an oscilloscope as I'm not too familiar with them but I've found there is a lot more science behind plug gap and coil selection than I thought, I'll have to do some more digging and research.

[VOS]

It needs pin-stripping too.

If a 25% boost in voltage would be useful, the factory would have supplied it.

Rise times seem to only limit the max RPM, as it's the fall time that fires the spark plug.

[Busted_PT]

Originally Posted by FlyinPurplePeopleEater

I do like the red color of MSD, if I remember right for the color to HP conversion red is about 50 extra HP.

Now only if it was red and had flames on it I would buy two for my car.

I wasn't too sure how the volts affect actual performance and kind of guessed it was more of an advertisement thing than anything else.

I will have to look into an oscilloscope as I'm not too familiar with them but I've found there is a lot more science behind plug gap and coil selection than I thought, I'll have to do some more digging and research.

Actually there isn't. Nothing to be gained by these. Just keep plugs changed at there change interval for what you're useing. And you won't be loosing HP that you already have. None to be gained but you can loose some to worn plugs.

[myckee]

Accel makes a nice yellow coil if you want to be different from the more common red and black guys.

[Busted_PT]

Or just paint it the color you wish. Just insulating anyway. May need to avoid metallics.

[Handy_Cruiser]

Originally Posted by FlyinPurplePeopleEater

I do like the red color of MSD, if I remember right for the color to HP conversion red is about 50 extra HP.

Now only if it was red and had flames on it I would buy two for my car......

I got ya' covered on the flames and high voltage coil. You will just need to make a few modifications to your ignition system and make sure to run solid copper spark plug wires.