280Z Distributor upgrade, coil options

[puretone]

Hi Kids!

 

I've done the distributor upgrade on my 1975 280Z.

Previous owner(s) did an engine swap and stuffed in a fresher L28 that's been de-EFI'd. It's got an Edelbrock 4bbl & Clifford intake manifold. I'm still cleaning up the former EFI wiring & getting rid of unused anything.

 

Anyways, it had a beat up old distributor with external ignition sitting in the engine bay...ballast resistor as well. Comical. So I got my mittens on a 1980 280ZX distributor with the E12-80 box attached to the side of the distributor.

I have an MSD 8202 hooked up right now to provide spark.

 

My question:

What, if anything, would stop me from using an MSD 8207 coil instead of the MSD 8202? It is not a question of frying the E12-80 box, right? The setup as-is right now does not require a ballast resistor, so using an even lower (primary) resistance coil shouldn't be an issue either, correct?

I realize the MSD 8202 coil works & suits just fine. I have a spare pair of MSD 8207 coils lying about that I'd like to put to proper use...besides that it is a smaller more compact & perhaps slightly more esthetically pleasing to look at coil, when compared to the old-school looking 8202 coil.

 

Any thoughts or input?

Edited May 23, 2014 by puretone

[NewZed]

Coil resistance determines, along with module resistance, the current through both the coil and the module.  More current = more heat.  You're already under the factory spec. with the 8202 coil.  The 8707 resistance is about half of the 8202.  You'll be reducing the odds of E12-80 survival.  But there are probably people out there using .355 ohm or lower coils with E12-80 modules.  Maybe they'll give some real world results.

Edited May 23, 2014 by NewZed

[puretone]

Coil resistance determines, along with module resistance, the current through both the coil and the module.  More current = more heat.  You're already under the factory spec. with the 8202 coil.  The 8707 resistance is about half of the 8202.  You'll be reducing the odds of E12-80 survival.  But there are probably people out there using .355 ohm or lower coils with E12-80 modules.  Maybe they'll give some real world results.

 

Thank you!

That does offer much needed insight. Flopping about on the internet, I have come to 'understand' that there are quite a few folks with 280ZX's using the MSD 8202 coil or something similar with a similar primary resistance as the MSD unit, so I figured not much harm can be done.

Of course the folks upgrading their 240Z's to the 280ZX/E12-80 also run into this conundrum...from the guides posted online, most opt to remove the ballast resistor as well.

The E12-80 and coil are both connected in series though, so wouldn't that reduce the stress on the E12-80 box? As in the highest load of current would still take the shortest route?

Also, it is safe to say the MSD 6AL ignition probably takes care of that extra heat/short life span of the E12-80, doesn't it? I suppose if I were to buy one of those I could pretty much use whatever MSD coil I feel like using on any given day of the week...

 

I should really stop tinkering with this set up, but can't stop my hands from doing what they do...an RB25 going in come next winter.

 

If anyone else has a thought, do by all means drop it on me here.

[z240]

The FSM for 81/82 that use the E12-80/92 ignitors, indicates the stock coil (no ballast resistor on these cars), should have 0.84-1.02 ohms primary resistance (EL-30 for the 81 FSM).  Most of the generic MSD Blaster coils have 0.7ohm primary resistance. Close, but it will run with higher than designed current and will shorten the coil life. By how much is your guess.

 

BTW, the 8207 has a 0.355 ohm primary resistance (all from msdignition.com) and will cause coil and or module failure fairly quickly.  You should be run with a 0.5 ohm or higher balast resister in line with the + terminal if you decide to use it. The MSD ballast resistor is apparently 0.8 ohm.

Edited May 23, 2014 by z240

[puretone]

I was wondering, in fact, about what the FSM listed as well. Would that coil have a resistor built-in? Just a curiosity from my end...

I pretty much know off-hand what the MSD coil specs are as far as primary resistance goes. Committed it to memory some years ago whilst screwing around with a friend's Honda.

I suppose connecting two ballast resistors in series to obtain something near the 1.0 ohm range would be a possibility. I have a pair of those MSD 0.8ohm resistors lying around doing nothing on the bench.

 

HOWEVER!

 

I just came across an MSD 6AL-2 at a seriously good price. Long live store credit! So I'll be hooking that up, instead of screwing around with ballast resistors & ignition boxes that may fry due to current mismatches.

 

Thanks for the insight! Those dudes posting their 280ZX distributor / E12-80 & coil upgrade shenanigans ought to adjust their guides to include the ballast resistor & why it is prudent to use said ballast resistor in the circuit...