Did something similar to that on my friend's race car. We used the warning light sender and teed it off to a relay inline with the MSD. It took some getting used to the fact that the engine would not fire until it built oil pressure. Definately not a bad idea, though. I have thought about doing the same kind of thing on a nitrous system. If I ever spray my engine, that is. Basically have it turn off the nitrous solenoid if the fuel pressure drops. Again, sounds like a good idea. One other thing to can do, although more costly, is to run an accumulator. This way, if you ever starve the pickup, or if your oil pump takes a shit, you have some lubrication to back it up.
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