Title pretty much sums it up. I saw a write up on here written back in '09 on how to wire in the MSD 6AL-2 ignition box, but my question is, is there any added benefit besides a rev limiter to an otherwise completely stock ignition system?

 

A rev limiter is a bonus?

The stock mazda coils are very robust, and are fine for high HP, an msd is not needed on a stock system, unless you got the whole thing for free, than sure, but paying full price, i wouldn't bother

 

So pretty much msd pointless, until you're modded to the point where you need it. I was just curious and didn't know if just 1 component would make a difference, or if you needed the whole system from coils, box, igniter, wires, and plugs and possibly new alt to make a difference.

 

I read up on this when i first got my rx7. I've had it on a few other cars but was running higher HP numbers. I decided against if because it seemed like minimal gain.

 

You could probably get more HP out've a full tune up, vacuum hoses, and maybe even exhaust, for the cost of a msd

 

Gotcha, so pretty much save the money and just keep on top of preventative maintenance.

 

I got a 6AL-2 in February for myself as a birthday present.

I wouldn't say useless in any regard.

 

An ignition box is not particularly useful on a stock or nearly stock car.

As for the rev limiter, that's enforced by the ECU. The box cannot increase the rev limiter, and if you intend to use it to decrease the rev limiter, then you need do disable the trailing coils as they will just continue to happily fire.

If you already have the box, then there's certainly no harm in wiring it up. I've had a CDI box on the car for...17 years or so...and while it was not useful until I upgraded to the point where it was (see below) it does have some very minor benefits. It does make a flood recovery easier due to a much hotter spark. And lets you get a lot more life out of a set of spark plugs.

If the car is upgraded to say a big turbo, standalone, etc. then the ignition box can definitely help at the high RPM under boost where the AFRs are richer. Stock coils can have a tendency to break up once AFRs are in the 10s under high boost. Additionally the ignition box makes the initial tuning a lot easier because while you are working out the richness, the box just powers through that extra fuel.