Engine and Transmission Tech

Are you guys familiar with the newer version of MSD ignition controller, "6AL-2"? If so, would you recommend it?

The "6AL" seems extremely popular with both racers and hot-rodders. One nice feature is its soft-touch rev-limiter. On the 6AL model, you select and plug-in a "chip" (which looks somewhat like a blade fuse) to set the rev-limiter at the RPM you want. The chips are sold separately, and come in 200rpm increments. On the newer "6AL-2" model, the rev-limiter RPM setting is changed via switch settings, in 100rpm increments. Once you figure-in the cost of chips, the price difference between MSD models isn't large. The 6AL-2 is physically smaller, plus MSD claims it's more powerful (535V/135mJ vs. 480V/115mJ). It seems like a no-brainer... which has me wondering why I haven't noticed any 6AL-2 boxes on cars yet.



the familiar MSD 6AL ignition...

Like i said on that other forum, "Don't pay for those fancy chips or pills. They are just a resistor. I had a friend that used to build an adjustable one with a 5 position rotary switch & 5 resistors."

Cool.

The two models do have two different circuit boards. I wonder how much different they really are. Didn't Pete Mantell's MSD toss its cookies during the 2007 meet? I wonder if the new box is more (or less) robust...

Since starting the current engine in the grey MGB there has been a slight hesitation to start and slight miss at lower RPM. Not bad but just enough to irritate. Checked the plugs, wires, etc. and no problem. Finally decided to put in a MSD 6AL that was laying around. While taking out the HEI GM module found one of the Mag leads pulled out and loose. Part of the installation was eliminating the module so it was easy to make sure there was a good connection. On re-start it tripped over itself trying to start! A lot more power was available from bottom end to top end. So, was it the loose connection or the MSD unit that made the difference? No idea but it was a big 10 on the grin factor!
Bill

I had an MSD 6AL fitted under the glove biox. It worked fine, but emittrd a constant humming noise due to a coil ionside vibrating. I replaced it with a Crane unit that was completely potted inside and is totally quiet. Both units worked the same.

I've used the old 6AL on many vehicles and had great success.
There are two issues however that need to be kept in mind.
The first one is noise, as Larry pointed out. Because these are analog boxes they emit an annoying whine while in operation.
(kinda like me when the scotch runs low)
No problem under the hood but it will drive you crazy if mounted inside the car.
The second is again due to it's analog design. It's EMF emissions are quite high. This can be picked up by your sound system or if you have fuel injection it can cause all sorts of odd behavior.
I have not yet tried the new one but I understand that it's a digital design that is far superior.
IMHO MSD has made great products for years and I assume that they will continue that trend.

Cheers
Fred