I don't know where you are getting your information from, but it is pretty skewed. If you look at the wiring diagrams for all 1985-1986 cars, no matter whether they are CFI, carbureted, 2.3, 3,8, or 5.0, they all have the resistor in line. The 1985 fuel injection was a throttle body version which was basically divorced from the ignition system and so that those engines had fuel injection made absolutely not one whit of difference. People have been swapping Duraspark ignitions into older cars for over 30 years now. They've pretty well have figured out what does and does not work these days, regardless of how Ford might have implemented this or that particular model/engine specific application. Many people here have not only done such Duraspark swaps, they have been running them successfully for years and years.[/QUOTE]
GypsyR: My bad, sorry I accidentally included your quote with Texas. I agree with everything you say. The coil he suggested was a .7 ohms with no resistor. Given a system voltage of 14v, that coil would draw 20a. Way too much for the ds2, and it's limited fixed dwell. Stock resistor is 1.1 ohms, with coil of 1.17, for total of 2.27 ohms. Stock would only draw 6.16a. He's running a rtr msd, so of course he can run a low resistance coil at full current-it has some kind of dwell limiting or current limiting circuitry unlike my ds2. So, my apologies gypsyR.
That being said, can you give me any specific examples of resistor/coil combos that are known to work well?
In my 68, to match output on ds2 setup (2.27 ohms ), the resistor wire is 1.35 ohms. I need a coil of .92ohm. I couldn't find anything in that neighborhood. Closest I came up with was msd .8 ohm with 1.5 ohms petronix coil, coming in at 2.3 ohms total. Easily within the range of the factory coil/resistor ohm tolerance. My problem is this, is this acceptable? 14v ÷2.3ohm=6.09amp. Nice. But ....when you compare watts in stock system the 1.1 ohm resistor, produces 41w of heat. The 1.17 ohm coil receives 44.4 w. New system: 6.09 amp total. Volts=amps×resistance
Resistor = .8. So voltage drop=6.09×.8=4.872. 4.872v×6.09a=29.7w heat from resistor. Coil resistance =1.5. Vdrop =6.09×1.5=9.135v. 9.135v×6.09a=55w.
So with this setup I will be pumping 55w as opposed to 44w into the coil, while not overburdening the ds2 module(actually slightly less strain)
Is an extra 25% more energy into the coil TOO much? Will it cook it? Seems reasonable to me, but can anyone confirm?