Ok so here is a picture of 3 ignition coils that Im currently looking at, I was comparing the numbers up until I realized I had no idea what they meant lol. I tried researching but I think ittl be better to ask some to help explain this to me and help me pick the best ignition coil that I can for my car
Just go with a stock coil unless you have some serious reason you need somethign else. It will cause you a lot less grief if you do, some aftermarket coils can draw too much current on the primary side for your system to provide. Larry
I went with the MSD Blaster 8226 coil on my stock 88GT with Taylor wires and NGK copper plugs. It's worked great so far, I've put a few thousand miles on it and driven across the country with no problems. It's probably overkill for a stock motor and others WILL tell you so but I haven't burned up my ICM, even driving uphill in the summer with the A/C on. So this particular coil seems to work fine with stock, for me anyway. A stock AC coil will do fine too of course. Buy what you want though. If having an MSD coil makes you feel better, I can tell you I've had no issues with mine.
I went with the MSD Blaster 8226 coil on my stock 88GT with Taylor wires and NGK copper plugs. It's worked great so far, I've put a few thousand miles on it and driven across the country with no problems. It's probably overkill for a stock motor and others WILL tell you so but I haven't burned up my ICM, even driving uphill in the summer with the A/C on. So this particular coil seems to work fine with stock, for me anyway. A stock AC coil will do fine too of course. Buy what you want though. If having an MSD coil makes you feel better, I can tell you I've had no issues with mine.
When you choose a coil with a smaller (mH) inductance you are shifting the spark energy to the upper rpm band.
If you need high rpm ignition power (IE: Turbo) then this may be a good choice.
The thing to remember is spark ENERGY delivered. It varies as the square of the primary current flow and linearly to the inductance.
The current is limited internally by the hei module...no need to worry about that.
In quick form, in an inductor the current builds as a linear ramp with voltage applied. At idle, when the available time is large (Dwell), the current ramps to an upper limit, as defined by the icm (usually about 5A). It stays there until the primary current is interrupted, causing a spark on the secondary.
At higher rpms, the dwell is short...too short for the current to hit maximum. So, we loose some spark energy. As the sparks per second increase (Higher rpm, cylinder count etc), the available dwell, and so the available current and spark energy diminish. The way to minimize this effect is to choose a low inductance coil, so the current builds faster, thus the spark energy doesn't diminish as much.
This is why DIS is so good, the effective cylinder count is 2, giving a large amount of dwell time even at high rpms, and therefore consistent spark energy.
As some have already pointed out, go with an OE coil otherwise more likely than not you are wasting your money. Coils in modern ignition systems will only deliver as much spark energy as needed to jump the gap and usually aftermarket high performance coils require use of the entire high performance ignition system to get the added performance potential that is often advertised out of them. If you search the net you can find numerous threads stating ultimately no difference noted in cars that actually have a spark energy problem due to considerable modifications out pacing stock capability, when aftermarket coils alone are swapped in over stock and in some cases matters got worse which I experienced. If you have a bad coil, any good coil will make the car run better.
Just trying to help you avoid spending money on a part that is unlikely to make your car faster or more dependable. Fortunately I was able to get my money back off a used electrical part. Don't fall prey to advertising. This is governed by the laws of physics.
Ignition systems will deliver enough VOLTAGE to jump the gap, but energy is related to how ling it will maintain the spark at a given voltage. That is why we are trying to max out energy where it is needed.
He's right though, a high performance ignition will deliver a higher primary amperage than a stock one, thus increasing the delivered energy at all rpms, but are substantially better for low inductance coils.
If you are not boosted, the stock coil will be fine. You have to need more spark energy before it will give you any gains.
When I was replacing the bad looking coil for our 2.8L stock engine I first purchased a AC Brand coil. When I opened the box to do the install I noticed the coil pot (for lack of a better name) was loose inside the steel hoop ( still lacking a better name). I then asked for a different brand and the counter guy pulled a BWD brand, same problem. Yep, the BWD looked just like the AC and probably from the same place. I then looked at the MSD Streetfire coil which looked better built, no looseness with the pot and had a epoxy cap layer on the pot. The coil was installed and has been working fine for 3 years with the stock AC ICM, AC Pickup coil, AC Plugs and a set of FS 7.5mm plug wires. Also the guys above are right, you will not notice any real performance gains with the MSD Streetfire, but the red coil does look nice under the hood and no loose pot to vibrate around.