Gear Shifting Theory

[Dave 53]

I took a close look at some video data logging.

I use Motul Sport 5-40 oil.

With the 10mm pump, my general observation is, at about 220 degrees and track RPM (4k-7k), psi is steady at 50 on straights and drops to 25 in turns/hard braking. In long turns, it drops to a steady 25, then climbs back up to 50 straight. I'm thinking 25 psi is a bit low at 7,000 rpm? On acceleration, it seems to hit max psi around 3,000 rpm.

Not much data on the 11m pump. First two sessions with it were a fail and I only got one lap in at a fast warm up pace before my axle broke. But the data on that lap: Oil pressure is not a function of straights vs. turns - it holds rock steady at 75 psi regardless. 90psi under 180 degrees out of the pits. Rock steady 75 psi once warmed to 220 degrees. On acceleration it seems to hit max psi around 2,000 rpm.

Curious to see psi at around 260 degrees. It was a nice cool day at Laguna but 100 degree track days are common here in California as are 260 - 270 oil temps.

I'm surprised to see this difference in performance profiles of the two pumps (and other unknown or considered factors). It will be very interesting to compare data of the 2 pumps on the same tracks. In the meantime, based on this limited data, it seems to me the 11mm pump's steady 75 psi beats the 10mm drops to 25psi. But, I'm learning, so maybe not?

Jim (and anyone else), what conclusions can you make based on this limited data?