Im thinking of asking for an ignition box for christmas, but im not sure what kind to get. Do most of you guys run MSDs? Also has anyone ever noticed an increase in power or do most people buy these for their rev limiter capabilities? Any comments and opinions appreciated

 

There is already a rev limiter built into the stock PCM. I got mine for the Multiple spark, stronger spark, and the ability to use an adjustable timing retard for nitrous. I just got the 6A.

 

Mallory 685. You won't be sorry.

 

My Mallory died on me, but it was probably because I mounted it in the glove box. I have the MSD 6AL now mounted in the engine bay.

The stock rev limiter is not very good, from what I've heard. Something about because it cuts off the fuel instead of spark I think. It probably isn't very reliable either.

You should notice a difference with your setup going to any aftermarket ignition. The 685 does have a lot more features and is great if you plan on ever having nitrous.

 

That seems pretty accurate. Before my H/C/I, I've bounced off the stock rev limiter before and it stuck there for a bit, then slowly went down. Afterwards, my PCM rev limiter was higher, but I still had a 6000 pill in my 6AL. When I hit 6000 it fell flat on its face.

That said, I'm pretty sure a box won't do much on a stock engine, but once you start turning higher RPMs it helps out with a better spark. I run a MSD 6AL and I like it, but I also plan on running N/A.

 

I actually just sold my timing retard box becuase i don't plan to run nitrous, but maybe the box i get will have it built in. Does the 685 come with retard built in? Also if i go with the MSD 6al do i need to buy a wiring harness to go with our cars or should i be all set? Keep the opinions coming guys.

 

The 685 does have the timing retard built in. It's digital so you can change all the settings without pills as well. It's better compared to the MSD Digital 6 box I believe, at least not the 6AL.

MSD does make a wiring harness that will work with either ignition box. Just make sure you get the 96-97 one.

 

What do you mean "pills" to change settings?

So no matter what kind of ignition box i buy, i need a wiring harness? I have OBD1 tuning so i guess that means i need a 93-95 one.

 

You generally need a wiring adapter to hook up to your coil unless you want to cut and solder wires.

The pills are MSD specific packaged resistors which fit in a socket on the box and simplify setting the rpms but then you have to have the ones you need or an assortment. Some newer modules tend to be digital with a built in display and keypad for setting rpm and other settings.

 

The adapter you need is dependent on the ignition coil you have. 96-97 coils have a single connector whereas earlier models had duals, or vice versa. I have an extra adapter for a 95 if you end up needing it.

The MSD uses different pills or modules to change the rev limiter settings. They are basically just a resistor and the ignition box "reads" that resistance and it correlates to an RPM setting.

 

i vote for the msd digital 6, ran one in my 79 and now im going to swap it into my 95

 

thats weird, becuase it says that the rev limiter is "soft touch" adjustable. Are these pills included with the boxes?

Also is it hard to wire these things up guys? I have an aftermarket 5" tach w/ shift light if that matters.

 

It's not hard at all. Actually, your tach can connect directly to the box. Using the wiring harness makes it a clean install without cutting any wires.

The 6AL comes with maybe 3 pills or so. A 3k, 7k and 8k I believe. It's adjustable depending on how many pills you buy, lol.

 

How much are the pills? I dont think it is safe to spin my lt1 to 7k, and i don't want to buy more pills if they are expensive. maybe i will go with the 685 then. Any objections? Thanks for all the help seawolf and everyone else

 

the msd digital 6 is all fully adjustable, no pills required, it has a rev limiter adjustable in 100 rpm increments and a 2 step rev limit for launching, and a single stage retard for nitrous etc. also comes with a start retard if you got compression etc.