Hot VW's - September 2010 - Digital Distributor
CB Performance's popular Magnaspark II™ billet distributor is now programmable!
BY BRUCE SIMURDA
In early 2010, CB Performance released their new Magnaspark II™ line of billet distributors. Basically, these are hand-assembled mechanical advance distributors with CNC-machine aluminum bodies and an injection molded cap with brass terminals for long life and conductivity. Besides being manufactured of quality components such as a 1/2-inch diamter hardened steel shaft, sealed upper support roller bearing and bronze lower support bushing, they were designed to be adjustable to tailor them for a wide variety of different applications. With their polished aluminum housing, they look great as well.
Since they are mechanical advance distributors, like all others they operate on a system of weights and springs. As ordered, they come with 20° of internal advance, and springs that closely resemble the advance curve of the popular Bosch 010 distributor, a longtime favorite for performance minded VW enthusiasts. For those who want to "tune" their distributors to match the special characteristics of their engine, each Magnaspark II comes with two additional sets of advance springs for a total of six different advance rate possibilities. There are also three additional advance stop bushings, for total internal advances of 20°, 16°, 12° or 8°. For those running turbocharged engines, it is also possible to completely lock-out all advance with a simple 10-minute adjustment, after the distributor is removed from the engine.
To make the Magnaspark II as versatile as possible, it is currently available in two versions - one for use with an external spark controller box such as the MSD 6AL or 7AL, and another which is compatible with a standard coil. The external ignition version uses an internal magnetic trigger, while the slightly more expensive coil version uses the magnetic trigger along with an ignition module. Both use the same CNC machined reluctor pickup to fire the trigger and, according to CB Performance, control spark all the way from 50 to 10,000 rpm.
But there is something new on the horizon. With all of CB's research into electronic fuel injection, it was only a matter of time until some od it would spill over into other components as well. In the igntion department, it's their soon-to-be-released Magnaspark "Digital" distributor. On the outside, there appears little difference between the Digital version and either of the mechanical Magnaspark IIs. But on the inside, it's night and day. Inside the Digital version there are no springs and no advance bushings - they've been replaced with a microprocessor. Inside the microprocessor are four pre-installed and non-erasable spark tables - two for naturally aspirated and two for turbocharged engines - as well as four blank programs that you can build yourself via a laptop, and CB's own proprietary software. Switching between the different tables is a simple matter of flipping the series of four DIP switches located on the processor inside the distributor.
The new distributor was designed to sense both engine rpm and vacuum (manifold absolute pressure, or MAP) in determining the proper timing at any given point. The resulting 21x21 unit spark table provides 441 different spark settings throughout the rpm and vacuum ranges. According to Pat Downs, who is the head of CB's R&D team, the Digital can also be programmed on an rpm curve only, but is most effective when both rpm and vacuum are used.
We won't get into the fine details of setting up your own custom spark table, but it is a simple matter of determining your engine's timing requirements. To simplify matters, you can take one of the pre-installed programs, transfer it to one of the four user programmable program spaces, and then simply modify it. One of the neatest aspects of this system, which is much like CB's electronic fuel injection, is that youcan try various programs and then save them to your computer as you go, so you never lose a combination that you like. Also, you can store different spark tables for download to the distributor when you need them. For example, if you have a buggy that you use in the dunes from the dry deserts of Glamis to the moist beaches of Coos Bay, Oregon, you may want to develop widely different spark tables for the two areas.
But the adjustability of this new distributor is only part of the story, as it also has many other built-in features not found on any other stand alone ignition. Some of the neatest have to be its built-in rev limiter, and two-step! That's right, the built-in rev limiter can be set at any rpm up to 10,000 by a simple click on your computer. And you no longer need an outside controller to install a two-step on your car. A third wire coming out of the distributor is simply routed to the two-step switch, and the rpm and timing parameters set using the computer program. For those who aren't familiar with a two-step, it's what drag racers use on the line to keep their engines at a certain rpm and while they have the throttle smashed to the floor, waiting for the green light. You may be more familiar with a the brap-brap-brap sound they make, just before the driver releases the two-step button, and the car launches down the track. With it built right into the distributor, it's now a much easier install for the average street/strip racer. One additional feature of the Magnaspark Digital is a Data Log, where you can actually play back your last run in real time with graphs on rpm, timing, MAP, and voltage. Cool or what?
The new Magnaspark Digital, which will be available in late September, is compatible with any coil, as well as external control boxes such as the MSD 6AL and 7AL. It is also recommended with their Magnspark II Super-Coils and 8.2 plug wires. With the electronic age upon us, it's only natural that a quality programmable distributor for the high performance VW engine would become a reality... and now it is.
But each of the three Magnaspark distributors has its place for performance engines. The ready-to-run Maganspark II is a drop-in and run type distributor for use with any coil. The magnetic trigger Magnaspark II is a drop in type also but requires the use of an external MSD ignition box. For those who are most computer savvy, wanting the most precise timing possible, the Magnaspark Digital just may be the best choice.