Digital MSD 6A

[wetminkey]

I have a new item on my workbench for my Spider - a digital MSD 6A ignition control. Since my engine has none of it's emissions controls (and I'm in Colorado), I'd like to improve the fuel-burn, both at idle and at higher rpms. This will do it - I know because I already own three other installed MSD 6As.
The MSDs 'hate' being in a hot environment, and I do not think that I can mount it to the passenger's-side inner firewall (too crowded,...), so I'm thinking of mounting it to the underside of the relay 'tray', just below the glovebox - looks like it will tuck-up under there pretty well.
I don't really want to extend the wiring with heavier wire to mount the device in the trunk,...and I don't think there are any other 'hiding places' in the car that are large enough for the MSD box. The box is about 2" thick and 4"x8".
Does anyone have other mounting suggestions?
Secondly, I'm looking for a path to run the wiring into the passenger-compartment. I suspect that the firewall, just below the cowl drain on the passenger's side, is a single sheet of steel that I can bore through and grommet. Anyone know for sure? I'd prefer opinions before I drill anything,...
Thank you, all!
Todd.

[Nut124]

Sounds interesting. What is the theory behind any improvement?

[wetminkey]

Three full-energy capacitive discharge sparks at TDC, up to about 3000 rpms,...single pulse beyond those rpms.
But capacitive discharge, as opposed to inductive discharge spark,...using ~530V for primary voltage, to attain about 45,000V secondary.
The powerful ignition spark burns fuel more efficiently (more completely), and keeps the plugs cleaner, longer. Ignition gaps can be opened about 0.05" beyond stock measurements for a larger initial spark.

[kilrwail]

Since you already have MSD systems, I’m sure you’ll be using an MSD coil with it. Regarding spark plug gap, I use 0.050” in my Porsche compared to a stock setting of 0.032”, based on MSD’s recommendations. That’s an increase of only 0.018”, much less than the 0.05” you mention.

[wetminkey]

My mistake, of course (!),..."gap can be opened up in 0.005" increments",...and I would guess that 0.040" - 0,045" would be about max,...
Question: how did you enter/exit the passenger compartment with your MSD wiring? Thanks.
My car is just back from alignment, and I hope to begin this installation later this year,...
Todd.

[kilrwail]

My MSD is in the engine compartment on the left side, in the location of the original ignition box. I've seen them mounted under the back window (with a gutted interior) by simply passing wires through the rear firewall. For the Fiat, I would try to make room on the right inner fender and keep the wiring up front.

[wetminkey]

I would LOVE to keep the MSD under the hood, kilrwail - all of my other installations are done that way,...but American vehicles have a lot more room to keep things away from the exhaust manifold!
I worry about the effect of heat-soak on the electronics, coming from the exhaust side of my Fiats' engine, and there is no room to mount the MSD on the drivers' side,...
Mounting under the glovebox would keep the unit cool and not extend the MSDs' existing wiring. It will also keep it pretty well hidden, which I would prefer. I hope to run the wiring through the firewall at a point just above the top of the passengers' floormat.
Thanks for your input, though. I do appreciate any info,...

[wetminkey]

Back at it today,...
The hole is drilled and enlarged with one of my 'rattail' files (final opening is just under 3/4") - directly outboard of the passengers' cowl drain tube. I lined it with a rubber grommet, and ran the wires for the MSD through the firewall.
Arranged the wires and gathered the supplies I will need to make each of the connections to the Spider.
That, and getting the box mounted to the underside of the relay tray (under the glovebox) will be next,...

[dinghyguy]

is thee not enough room on the relay panel? Also it is too late but you could put it under the cowl....... or in the radio position,,,,,,,

cheers
dinghyguy

[wetminkey]

Water and electronic ignition don't mix well, in my book,...so no to the cowl position.
And I have a very nice Sony Xplod receiver that occupies the old radio position (20W x 4!),...but under the relay tray will work perfectly, I think. The MSD unit is 4" thick, and (it seems) should not be a bother to a passengers' legs,...
Anyway, my Spiders' ignition is about to have significant gains in performance!

[wetminkey]

Oh my goodness! How very nice! And I haven't even driven it,...fired right up.
Installation went completely uneventful, so I'll only bore you with a pic, or two. First, the location of the ~3/4" hole (to accommodate both the wires, and the rubber grommet):


Nothing can be detected under the hood, other than a grommeted hole with wires between the auto tranny dipstick and the windshield washer reservoir. Best yet, you can just barely see the MSD box mounted under the relay tray:


And it will never interfere with any passengers' legs!
We'll be running MUCH better, and burning fuel more completely, from now on,...
Happy Motoring!
Todd.

[wetminkey]

Holy Smokes! It's a Spider!!
Never has the car performed like it did today,...with no other ignition changes. Wait until I re-time, re-tune the carb, and open the spark plug gaps!
This is an entirely different car than the one I bought 21 years ago,...