Garen

I'm thinking of switching to an MSD unit, and noticed that there is now a digital version in addition to the standard MSD - 6 AL.

Comments on any experience with this setup will be appreciated.

Thanks,
__________________
Garen (87 930 CS)

Chuck Jones

I think you'll find a lot of folks....including me, who have used the "old" version and swear by it. I'd probably stick with the old version rather than use something that there's not much info available for. Digital doesn't necessarily mean better. Maybe later when it's been time tested and passed the rigors of track and street.

A930Rocket

What does the digital version do that the "old" one doesn't? Like Chuck, I've been happy with my "old" one.

Do you have a link?

DDD

Less voltage to run it, which is a minor difference.

Supposedly better precision timing because it is digital, but nobody is complaining about the analog unit in that regard, so minor difference again.

More bells and whistles when you get into timing retard under boost and the more advanced features. I think you get more programmable capability with digital.

Garen

Here are the differences (in bold), as listed on Summit's website. I decided to give the digital one a try. I know the regular one has quite a few fans, so maybe the new one's not bad either. I'll be the guinea pig... I'l post results.

Product Line: MSD 6AL-2 Ignition Boxes
Part Number: MSD-6421
Ignition Box Output: Capacitive discharge
Circuitry: Digital
Rev Limiter: Yes
Timing Retard: None
Data Acquisition: No
CD Voltage Output to Coil: 535 V
Spark Output (millijoules): 135 Millijoules
Minimum Operating Voltage: 10 V
Maximum Operating Voltage: 18 V

MSD is excited to announce the next generation of 6-Series ignition controls--the 6AL-2! These all-new ignition controls combine a new housing, new digital controls, and more power in a sleek package. You still receive the 20 degree duration of multiple sparks, combined with higher output to ensure complete combustion. There is a 2-Step rev control built into the housing, but there are no rpm modules! Adjustments are made via four rotary dials for 100 rpm increment control! The all-new capacitive discharge ignition will easily connect to nearly any 12 V negative ground distributor system, even Hall-effect pickups. They offer higher output, with up to 135mJ and 535 V, and accept points and mag pickup triggers.



Product Line: MSD 6AL CD Ignitions
Part Number: MSD-6420
Ignition Box Output: Capacitive discharge
Circuitry: Analog
Rev Limiter: Yes
Timing Retard: None
Data Acquisition: No
CD Voltage Output to Coil: 460-480 V
Current Draw: 1 amp per 1,000 rpm
Spark Output (millijoules): 115 Millijoules
Minimum Operating Voltage: 10 V
Maximum Operating Voltage: 18 V
CARB EO Number: D-40-26
Notes: Even-fire only on V6.

These MSD 6AL ignitions are the perfect choice for the street or the track. The powerful capacitive discharge, multiple sparks ensure complete combustion of the air/fuel mixture to increase power and performance. MSD has taken the proven performance of the 6A and added a rev limiter. The soft touch rev control will protect your engine from overrevving. Adjustments are easily made with plug-in modules, so there are no dials, switches, or programs to deal with. At your selected rpm, the soft touch begins dropping the spark to some of the cylinders, and on the next cycle, these same cylinders are fired to prevent loading up with fuel. The result is a smooth and accurate limiting action without backfires or roughness. They'll work with virtually any 4, 6, or 8-cylinder vehicle with a distributor, as long as it has a 12-18 V electrical system. They include rubber shock mounts and modules for 3,000, 6,000, 7,000, and 8,000 rpm.

Regards,

Garen (87 930)

DDD

Digital has been around a long time. This is the equivalent of going to an LED energy efficient light bulb. You pay more initially but for a slightly better product.

You will be fine with it!

Garen

Yeah, it didn't sound too different from the tech specs, and it was not too much of a price hike either, so I went with it. Parts arived today. I like the dial-adjusted rev limiter as opposed to the "pills" you would get with the analog version. It'll hopefully be on the car by the end of the weekend, if I get some spare time...

-Garen

A930Rocket

The adjustable RPM limited is worth it alone. I've changed pills a few times be lost them...

What does the 2 step rev control do vs. the 6AL?

Garen

The two step is essentially 2 rev limiters. One is the max revs, the other is a secondary one that is activated by a 12V switch. It can be used for launch control, activate the trans brake on drag cars. One cool use would be to lock the switch (with an old-school computer lock, for example), set the RPM to a low 3000 or so, and use it as a valet/teenager/etc setting. Being that my little girl's only two and a half, and that the car doesn't get valet'ed, I think I'll leave the second circuit alone for now. On the other hand... it could be cool to use it as a secret "slow-the-instructor-down" switch.

-Garen

nathanUK '81 930 G50

I'm going to try and use my EBC to help launching at the drag strip. I will have the EBC off when launching so I will only achieve my Tial WG spring pressure (0.5bar spring) and then release a button (possibly a button that mounts to a steering wheel hub) to take me up to 1bar with my EBC.
I found with my 930 too much boost just lit the tyres and no boost was embarrassing

Would the ignition limit kill boost pressure? Or would it be OK?

Garen

Nathan, I think your way is better, since it will allow you to rev out at the lower boost level. You can possibly use the 2 stage rev limiter on,y at launch, so you can floor it and get off the line at whatever RPM your car hooks best. Then, you do most (if not all) of 2nd with the low boost, and switch the EBC on for the remainder. I don't think having the engine sputter through 1st gear at 4000-5000 rpm will be quicker than what I described above.

-Garen (87 930)

nathanUK '81 930 G50

Yes, I think you're right.
At least with some way of reducing power, the turbo can be kept spooled as the throttle is wide open.
I wonder if my spring will be low enough to get neatly off the line. I've heard that too low a spring can cause difficulty for an EBC to get to the max target boost level. I'm aiming for 1bar with a 0.5bar spring which I think will be OK as the spring will likely give me 0.6bar of boost leaving only 0.4 to make up. I hope 0.6bar is not too much boost for launching at the strip. I have 285's on the rear with a G50/01 and the car weighs 1225KG with very little fuel.