512 BBi ignition upgrade

Upgrade is maybe a wrong word, perhaps the headline should have been "alternative ignition system". Anyhow, as some might know, I've had some a couple of issues with the original Digiplex ignition box in my 1984 BBi. First annoying issue was the high pitch noise coming from the box. The noise penetrated into the cabin and took the focus from the beautiful flat twelve sound. Secondly, I've noticed that the spark became less intensive when the unit got hot making the car difficult to start. Thirdly, I noticed that my instruments sometimes started to move erratic. Due to the problems, and much inspired by fchat member alhbln, I decided to change out the ignition box and associated coil with a MSD 6AL ignition box and a Blaster 2 coil. I removed the digiplex and coil 6 weeks ago and installed the MSD box and coil in a few hours. The conversion was very easy and alhbln have, as usual, made it even easier by supplying a diagram and easy to follow instructions:

http://www.dinoplex.org/PDF/Wiring_MSD6AL2_for_AEC104.pdf

I tested the ignition the following weeks and the car have run like a dream ever since....No noise and flawless starting, cold as warm. Only downside was the visual appearance, a red box on the firewall and a chromed ignition coil right in your face when you open the engine lid. Completely unacceptable obviously. After some considerations I finally decided to rib the guts out of the Digiplex and try to hide the MSD circuit board in the original Digiplex casting. This task is quite challenging and feels a bit destructive, but it can be done with simple tools and it makes a fine DIY weekend project. I first started to make the coil look a little more as the original. Flat black paint and a aftermarket sticker made it much nicer to look at. I'm still trying to source a sticker that is completely identical with the original, but this can do so far:

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Next job up was removal of the circuit board from the Dinoplex housing. This is not a job for faint hearted! The board is completely submerged in a hard Epoxy like
substance. I used a paring chisels, normally used for wood work, and a big hammer. I was done after approximate one hour of hard work:

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Then came the most interesting part of the job: Fitting the MSD board into the old casting. Due to the MSD board complexity with components on both sides and general fragile look (I'm a analog guy) I decided to keep the original MSD box and modify it to fit inside the Dinoplex. I ended up chopping the top and the cooling fins off the MSD box before I could fit it. It is a tight fix, but that is good for heat transfer. I reused the old Dinoplex connector and added an additional connector to the Dinoplex box in order to keep the original wire harness in the car. Upon completion of the "Old Box" Installation in the car was done in less than 15 minutes and I just test ran the car...It's running great

Best, Peter

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Dinoplex off cause, Thanks Steeve. Too late to edit the first part of the thread. However here is a few more pictures:


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Thanks Don. The sticker is from Superformance. It doesn't have correct layout and type number, but close. Maybe Kilimanjaro design have the right one? The whining was unacceptable and the unit weak when getting hot. I don't go that much to Concourse arrangements, I only drive the car....-. Next time it will be a Pertronix or similar unit....I had already bought the MSD unit when I learned about Pertronix. I hear a lot about quality issue with MSD so maybe time to look for alternative hardware. My impression is that there is a lot of new aftermarket junk around with only a few years lifespan before it craps out.

Best, Peter

 

For reference and sake of good order I just want to add this chapter to my ignition thread:

There are two versions of the MSD box. The one I converted to first were the standard non programmable version. Using this box you still need to maintain the original advance system. I have now converted to the programmable version of the box where you can delete the original advance system and program your own advance curve via a PC. I have then locked out the distributor and phased the rotor to fire exactly across the distributor terminal half way through the advance curve (@21 deg). I have programmed the advance curve so it is identical with the curve in the user manual for BBi. Every modification is completely reversible in a few minutes should anyone wish to convert the ignition back to the mechanical advance system.

This is the adventure:

First removal of the advance weights

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Then +- 5 degree facing of the rotor position relative to the reluctor wheel. The rotor shaft can be pressed out and turned approximately 5 deg.

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Then locking the distributor shaft. I used a small metal plate and tag welded the rotor shaft to the distributor cup on both sides:

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Then uploading the advance curve from the PC into the MSD box and go for a ride.

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Next up is to fit the ignition into the Digiplex box.

Best, Peter

 

Note for information that the whole setup is still kind of a test regime. The programmable ignition is build for max 8 cylinder engines so you have to tweak it by multiplying the rpm's with a factor of 1.5 times the actual rpm's of the twelve cylinder engine. Same goes for max amount of advance you can obtain. The box is good for 25 deg but I loose a factor 1.5 of that equals around 17 deg advance max and I need 22 deg (10 to 32 deg) to be in compliance with the original advance curve. For now I run 15 deg advance in idle and let it build up to 32 deg at 6400 rpm. You can pull out further advance if you install a map vacuum sensor and I am considering that.

Best, Peter

 

I have now programmed and uploaded the final advance curve. I've settled on a compromise with 14 deg advance in idle and 31 deg advance at 6400 rpm. The car runs very well with this setting and there is no need for reducing advance in idle by adding a map sensor. See my latest curve below and note that the curve is a retard curve so all values must first be divided with 1.5 and then subtracted the 31 deg static ignition setting to give actual advance figures:



I have also build in the MSD circuit board in the original Digiplex box as can be seen below. The car is now back on the road and running on full digital ignition with no mechanical advance system worries.

Best, Peter

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MSD claim they have a less than 1% failure rate on their units? But that said some years ago rumors were that they had quality issues. But imagine selling delicate, sensible and digital ignition equipment for DIY installations. Crazy guys like me ripping out the circuit board and making amateur installations of varying quality. Who is to blame when the box stops to work? Was the box installed in an extreme hot environment, was the box installed on the vibration dampers and the list goes on. MSD boxes are sold in vast quantities, mostly to amateurs, and I can imagine that it is easy for the company to be blamed for any problems regardless of the actual conditions around the installation. I am now running two programmable units and I have tampered with both and I have not had any issues. The day I have an issue I will just toss the box in the bin and buy a new one. The cost is about equal to 2 hours of labor at my local Ferrari service workshop.



Best, Peter

 

For the 308 I would recommend the Electromotive Xdi ignition. I have run this unit in my 308QV for many years and it works flawless (See pics below). There are multiple threads to be found on fchat if you use the search section.

Best, Peter

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