Thoughts on MSD digital 6 box

[Jim Comet]

I currently have a 6AL (new in 1996) box that works fine. I need to buy a start retard box and new adjustable RPM module if I keep using the old box. These 2 items are about $210 bucks and I can get the new box for $350. I am thinking of upgrading to the digital 6 plus ignition (part number 6520) as it has 2 rpm controls as well as the start retard I am going to need. I am wondering if anyone has experienced reliability or functionality issues? Has MSD's quality suffered since Holley bought them? Thanks for you opinions. Jim

[thatdarncat]

I bought two used MSD digital 6 plus boxes off Craigslist and installed one in my car before Drag Week 2015, carried the other as a spare. They replaced a 6T and external revlimiter/two step combo box I had been using. I've had no issues, but it wasn't a brand new recent manufacturer box either. I've since picked up another digital 6 plus off Craigslist that is brand new in the box and never used, but was manufactured quite a few years ago. That one is going in my car I'm building. I have a MSD tester I use to check these when I get them, so far no issues.

[afret]

The start retard on that box is for 20*.  In my case 20* seemed to be too much and the car would backfire at times when starting.  I think with 20* retard, the adjacent terminal was getting fired causing the backfire.  I quit using the 20* retard on the MSD box (Digital 7) and just got a MSD Starter Saver which gives a choice of 10 or 20* retard and use the 10* option.  Haven't had a backfire problem since.

[BattlestarGalactic]

Since it comes with a start retard, you could lock your timing at 36-40*, that way the 20* retard would get it back to something close enough to start easy without going backwards too far.  If you still have mech advance in the distributor, I could see it being a problem.

[e philpott]

I've had my Digital 6 since 97 or 98 and have had no problems at all with it

[Jim Comet]

Since it comes with a start retard, you could lock your timing at 36-40*, that way the 20* retard would get it back to something close enough to start easy without going backwards too far.  If you still have mech advance in the distributor, I could see it being a problem.

My timing is locked out. I won't know what my total timing will be until the motor is dyno'd. I like the idea of having a low rpm limiter that the digital box has since I will not have a trans brake. I can set the limiter just below the threshold of what the line like will hold and leave off the line lock button. Jim

[e philpott]

I was thinking my Digital 6 had adjustable retard and not just 20 degrees take it or leave it short of looking at it tonight  , I have never used that feature but did have my Trans Brake working with it low rpm control when the brake was activated back when I used to Bracket race it , now have a 4 speed manual

[427HISS]

I'll be watching thid thread as I have s 6al and thinking of a new digital, as sometimes my motor has a tough time starting. I'm also locked out.
I assume, 10% would work.

[Jim Comet]

According to the MSD site the start retard is preset at 20 degrees on this unit. If you open the PDF instructions for the unit it shows it clearly. I have decided to do this but it will be a winter project for me. Jim

[fekbmax]

call me old school, or a dumb ass but im a fan of the old analog boxes. i have a couple un boxed NOS boxes, one 6AL and one 7AL2 as well as a couple re furbished boxes as well . there normally easy to repair although i don't think MSD (Holley) repairs the old boxes any longer but there's plenty of videos and home electronics hobbyist that can still do it. my dad (RIP) built CB radios, linear's and amplifiers as well as custom antennas and countless other types of electronic devices and would tackle anything electronic that had capacitors, diodes, transformers, tubes, ect, ect, he fixed the 6AL in my car now over 16 years ago and it still works perfectly .  he wasn't a car guy at all but he was my super hero. i miss him terribly ..


side note, this is a great book to have if you use MSD ignitions .
http://www.ebay.com/itm/MSD-Ignition-9615-Wiring-Diagrams-Tech-Notes-/292655982639?hash=item4423a7e82f

[TripleJ]

Keith, thank the info on the MSD book, just ordered one.   

[cjshaker]

side note, this is a great book to have if you use MSD ignitions .
http://www.ebay.com/itm/MSD-Ignition-9615-Wiring-Diagrams-Tech-Notes-/292655982639?hash=item4423a7e82f

An $8 book, and $16 shipping?!! What the....

[fekbmax]

there's plenty of other options for the book on flebay but they all come out around the same price,
ie, $24.99 + free shipping. some more, some less, just was giving an example of the book.

[FElony]

https://www.ebay.com/itm/MSD-9615-Wiring-Diagrams-and-Tech-Notes/382516750802