xviper

The car's oil pump itself has its own spring loaded relief valve build right inside. The spring is what determines the max oil pressure the engine will get. It looks like a pretty "goof-proof" way to do it unless the thing breaks and since it is NOT under any rotational stress, I can't see it ever breaking.
If someone wants to find out what the max capacity pressure our pump will achieve, just go in and remove this spring, put a pressure gauge on and let 'er rip. Tell us what you find out.
(Since I don't want to be blame for blowing someone's engine up and in case there is someone out there that gullible, I'M JUST JOKING! I'm sure there's an easier way to find out if you really want to know.)

paulchr

max oil pressure/pressure relief valve is determined by the design team in the factory. this is different to the filter bypass valve which opens when the filter is choked for whatever reason, ie you have not changed it since new and now have 50,000 miles on your engine.