Hi guys. I fitted a MSD box to a ferrari 512BB and the owner messaged me to ask if it had a limiter fitted now as it wont go above 120mph? Has anyone had this before?? thanks
MSD has no clue how fast you are going, just what the rpm is. Could have a rev limiter, but that would work in all gears.
I think some MSD boxes have limiters and some don't. And they're in the form of a module you plug into the box.
I assume you kept the points in your distributor. Then you probably have one of their 6AL boxes. Some of the 6AL boxes do have a rev limiter. Their web site has a large amount of product and troubshouting information. I suggest you start there: https://www.holley.com/brands/msd/products/ignition/ignition_boxes/
I believe the BB512 uses an inductive pickup in the distributor. I believe you can get the MSD boxes with and without rev limit.
As Drew says - 512 BB is an inductive pickup and that some MSDs have limiters and some don't. None that I know of have a 12 cylinder limiter unless they have been sent to MSD for that particular modification. The MSD is just counting pulses to the point where the limiter kicks in. This means if the MSD thinks it is fitted to a V8, 6 or 4 cylinder it will limit the engine at a lower rpm than is shown on the device. So could be a limiter preventing the car from running to max. Hope this helps
As I opted for the Pertronix unit, (smaller and much more versatile and built for 4, 6, 8 & 12 cylinder apps) I didn't worry about this. But, as I recall the MSD had two rev limit options, 5500 and 6000...
