Not only does it use both plugs in each housing, it sparks both leading plugs AT THE SAME TIME!

 

the stock setup does not do this? is that why there is a power gian? cuz the leading rotor is not pulling the trailing one behind?

 

Right. The stock setup only has one leading spark per rotor face. The power gain not only comes from two leading sparks per rotor face, but also because there is no distributor cap and rotor to get in the way. Direct fire is just that; direct from coil to plug.

The thing about trailing is that it is anwhere from 8 to 20 degrees behind the first leading spark (not the second one that sparks 180º later). It doesn't add much in the way of power to the engine (mine was like 1HP or less when switched on and off while driving), but it does help clean emissions slightly.

One other thing I noticed about direct fire is how much cleaner my exhaust smelled. Stock leading and trailing couldn't give me those kinds of results. There were no emissions devices on the test vehicle. I'd guess that it would come close to passing now with direct fire, even without any emissions devices. Much improved over the horrible stink it used to produce.

 

hum....interesting...so how does the coil know when to fire if not for the distributor? do you still run the distributor?

 

there is also six links on the FAQ section, under the question "Can I convert to direct fire ignition?"

 

Yes, you still use the distributor. A stock electronic distributor (like those on the later FBs) has two basic parts -- the magnetic trigger wheel at the base, which tells the ignition when to spark, and the rotor and cap which determine which spark plug to send the spark to. In a direct fire setup (at least the ones being talked about here), the leading spark isn't sent through the rotor and cap -- it's sent directly to the plugs. The trailing spark still goes through the rotor and cap, since both trailing plugs firing simultaneously causes bad things to happen (see the No More Igniters thread).

 

"...bad things to happen..." could you give me a synopsis?