How to install MSD ignition box....

petex19

True Classic
:brow:Isn't Winter great. It may be cold out and the X's are put away but I'm lining up my projects to complete before spring.

I've read from various XWeb members that they are using a MSD box either 6A or 7A. I thought for sure that I would find somewhere a write-up about the install and the do's and don'ts but I can't find one anywhere so would anyone care to share their experience and what is involved.

I would like to connect an MSD 6A box to my Bosch electronic ignition and can I continue to use my MSD Blaster 2 coil or do I re-install the factory coil with resistor.

'PeteX1/9
 
I'm game for anything. Whatever works best just please show me the instructions and I will get it done.

'PeteX1/9
 
The MSD replaces the Bosh ignition box

The MSD website has a bunch of downloadable manuals for hooking up their ignitions. It's prety stright forward. Do you already have a 6A box or are you still shopping? The most bang for the buck (under $400) is the Programmable 6AL-2 . (here is a video of there 6A lineup) There is also a chart for matching up a coil to the ignition you're running here.

I have the 7AL-2 with the Pro Power HVC coil and about to hook up the MSD 7989 ignition controller. It's overkill for what I'm running, but I'll never need to upgrade again. I just wish they offered the Programmable 6AL-2 when I was buying my 7AL-2.
 
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No I don't already have anything other then a MSD Blaster 2 coil connected to the Bosch box. I know you are running dual DCNF's so this setup obviously works with carb'd cars. Their's alot of info. on the MSD website but which of the many setups is the best for an X and as far as different MSD box's goes is their really a difference between the MSD 6A and going with the MSD 6AL-2 which is programmable? I watched a video on MSD ignitions and they said that the MSD 6AL is just the 6A with a rev limiter. Is the rev limiter recommended. I understand that which model you pick comes down to personal preference and how much you want to spend so I`m asking you for your personal thought process and why you chose what you did. Cost is not a factor, I just want something that works and is worth the time and effort to replace the Bosch box.

`PeteX1.9 (my laptop just went into french keyboard mode so the backlash doesn`t work):mallet:
 
I had

a 6AL on my car at one time.I had mien hooked up wear the stock Bosch ignition was sending a signal to the MSD . what I found is there is no difference in performance at all.I was told from I think Bernice to get it to work right you have to eliminate the the stock Bosch box . the only thing I miss is the Rev control it was nice knowing I wasn't going to over rev the engine. the problem with MSD is they aren't as reliable as the stock Bosch ignition on my car the MSD failed after only a couple of years the Bosch unit I have is the same one I've had for 13 years.MSD units are vary expensive to replace wear the Bosch box is free I have 2 backup units.

MSD make a stand alone rev controller for 110 buck I'm going to get that instead.
 
The programmable 6AL-2

It will allow you to get rid of the Bosh box and provides multiple spark at low RPM for a more complete burn and a higher RPM capability. The big difference with the "Programmable" 6AL-2 is that it will allow you to lock the distributor and control the timing curve via the MSD box and your laptop computer. No more flyweights, springs, or vacuum advances!

How this works is... You set the distributor to the highest advance you want and the MSD box will retard the timing back at idle and slowly release the retard (advance your timing) until the MSD is providing NO retard aka max distributor timing. You can set how much advance you want at any given RPM by just the click of the mouse. No more swapping weights and springs to get the right timing curve.

As for wiring, 2 wires go to the coil, 2 wires go the the distributor, 1 ignition controlled (on/off), 1 wire for the tack and the two main power wires(+/-). As for all that other stuff like launch timing and nitro/boost retard, etc. you'll not need any of that stuff. I bolted the main power cable to the starter cable and just grounded it to the engine compartment wall. My car is an 85 with the FI removed, so there were a couple of places to get the keyed power from.

Locking the distributor MIGHT be the hardest part. I haven't done it yet, so I'm not sure how it's done. It seems like it wouldn't be too difficult, but we'll see.
 
Tach adapter

The problem with the MSD is that the output to the coil is incompatible with the trigger for the L-Jetronic (yellow wire to negative side of coil). This is due to the multiple pulses sent in place of a single one.

To resolve the issue, you need to use the MSD tach adapter, which unfortunately means that you will need to keep your Bosh ignition module (as this will drive the tach adapter). You may be able to use the hall effect output from your electronic distributor to drive both the Bosh module and the MSD, but at this point I'd suggest just driving the MSD from the output of the Bosh module as per the wiring diagram below:

wiringdiagram.jpg


Note the reference to "Fuel Injection System" above. This is exactly the application of this tach adapter in our case.

Edit: Just realised that you don't have fuel injection, but the post is still pertinent for those who do.

Cheers,
Dom.
 
Must be an old MSD

Mine had a separate wire for the tach and 2 wires for the coil. The only work I've done on FI systems has been to remove it, so I'm very unfamilure the the +/- of adding the MSD to a FI system.
 
That's locking the vacuum advance

Great info and a great illustration on how to do it. I went for years before I found that little modification.

Locking the vacuum advance allows you to remove the vacuum motor off the side of the distributor and turn the distributor 360 degrees without interference.

Locking the flyweights in the bottom of the distributor might require a little welding...maybe.
 
Welding would do it, certainly...

Great info and a great illustration on how to do it. I went for years before I found that little modification.

Locking the vacuum advance allows you to remove the vacuum motor off the side of the distributor and turn the distributor 360 degrees without interference.

Locking the flyweights in the bottom of the distributor might require a little welding...maybe.

I think most distributors have a curved-slot-and-pin arrangement. I would think that just filling the slot with JB Weld, thus locking the pin from moving in the slot, would do it.

Disclaimer - I've never done this and it's been a while since I took apart a dizzy! :mallet:

Pete
 
Before you go the MSD route -

You really want to take a look at the Allison's Automotive solution.
I've got nothing against MSD, (I've bought a few) but the Allison Ignition system really rocks. :headbang:
I installed one and it makes a very noticeable improvement in the ignition -plus it's distributorless.
Runs high RPM (over 10K RPM) as well.

Price might be lower for one of these over the MSD setup.

Again, nothing against the MSD, just a worthwhile easy install option that really performs well.

ignition1sm.jpg
 
Ahhh... OK

I really don't know much about this stuff, that topic just rung a bell so I hunted down Bernice's post. And I learned something too. :)
 
Bob... a bit more detail please...

Does the Allison unit allow you to "program" limits in stages or a single limit, and how does it set or sense advance/retard needs?

Thanks...
 
Good post Bob,
I had forgotten about Allison's as an option. Now having done this upgrade is there a write up on how to do it on XWeb as if I recall correctly the Youtube video is of the install on a 124 Spider. Does the Allison's unit work as a standalone of does it work with the Bosch box?

'PeteX1/9
 
Programmable ignition

Effectively this is the optimum solution. I have an Australian designed kit on both my cars (from Jaycar). My mum will be here (Munich) at Christmas time and will bring another one for Ulix.

More info is available at:
https://docs.google.com/fileview?id...2EtN2UzMi00NzI4LTliZDMtZmMzN2EzOWNlYjkw&hl=en

Not only do you get to program the advance curve on the basis of RPM and engine load but you also get the benefit of a bigger spark (adjustable dwell angle independent of RPM).

Cheers,
Dom.
 
Yes, it does...

Does the Allison unit allow you to "program" limits in stages or a single limit, and how does it set or sense advance/retard needs? Thanks...

I don't have a photo available, (I'm still on the road in Nebraska)
but the inside of this unit has the same mechanical advance as a standard distributor.
If my memory serves me, you get progressive advance up to 3500 RPM. (full advance at 3500 rpm)
You can change the advance curve by changing the springs inside. (like the old the distributor)

It doesn't interface to the MegaSquirt "yet", I'm working on that but it IS capable of sending down the RPM of the engine by way of the tach signal.
 
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