Quote:

The big difference between a high volume pump and a high pressure pump will occur at low engine speeds. The high volume pump will produce higher pressure at idle since it is forcing more oil into the engine. At anything greater than about 3000 rpm the high volume and standard volume pumps start to act the same since the relief spring is blowing off all of the excess volume.

This has been my experience as well. My race motor doesn't need the high volume, it idles at 1200 rpm, the oil doesn't get hot, and both pumps made the same pressure going down the track (using the same spring in each test).

My street motor needs the high volume pump at idle (IMO). It idles at 900 rpm (or less) and when the oil is hot, it is 25 psi. I don't want to see the idle pressure with a standard volume pump in that. Lots of bearing clearance, hemi wide groove 360 bearings (mistake), hot oil, low idle rpm, it all adds up.

1993 Daytona, 5.50 at 130mph (1/8) 1.19 sixty ft (PG). Link to 572 B1 - Part 1