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Rev Limiter Project

sah62

Member
For some time I've been trying to find a way to repair an original rev limiter circuit board and/or to turn an otherwise non-functional limiter into one that works. I've looked into custom circuit board fabrication, but so far the costs have been a little higher than I'm comfortable with. As an alternative I've been trying to find a new limiter that will fit inside an original case and work with original wiring. I recently found a limiter that appears to make the latter approach practical.

Pertronix makes a digital rev limiter that can be mounted to a fender apron much like our original limiter. Here's a description:

http://www.pertronix.com/prod/ig/drl/default.aspx

Current retail pricing runs in the $120 - $150 range. The feature set is nice, it has the three wires (ground, coil positive, coil negative) needed to work with our ignition system, and at first glance the size looked about right. I bought one from Matt Rosa of Ponderosa Mustang to experiment with after he assured me that it could be taken apart. I also took the original limiter off of my car to measure the internal dimensions and to see how the original circuit board could be removed.

After the Pertronix limiter arrived I got to work. It's held together with 14 small hex/allen screws in two different sizes. I opened it up and found a small, removable circuit board with all wires soldered in place. So far, so good.

I then turned my attention to the original limiter. It can be opened up by removing four screws from the back cover. The circuit board is held in place with two screws and four soldered connections. I removed the screws, took care of the connections with a soldering iron, and removed the board.

The Pertronix board was about 0.1" wider than the opening in the original limiter, so I used a Dremel tool to grind some material from both sides of the board. Once it fit I tackled the wiring. I removed the two extra wires (tach output and a wire that's not used for non-HEI ignition systems) using my soldering iron and experimented with ways to attach the original harness to the new limiter. I tried both soldering directly to the board and splicing the wires with soldered connections. Wire splicing was easier for me and there appears to be less risk of damaging the board if your soldering skills aren't that great.

I just finished the installation and testing this past weekend. It seems to be working fine and no one can tell that I have a modern limiter hidden inside my original case. Here's a write-up with pictures for anyone else who might be interested in doing the same thing:

http://www.musclecarresearch.com/limiter-upgrade.html

Please pay special attention to the warnings because Pertronix and I don't provide any warranty for the modified components or the procedure. Try it at your own risk because it can get expensive if you make mistakes.
 
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