Accusump - some data

[The Radium King]

when we are dealing with drops over fractions of a second, the time for the pressure sender to detect and open a valve is significant. if the only downside to having the valve open all the time is potential depletion of the pressurised oil supply, then using an accelerometer to open the valve in an anticipatory basis is a good compromise. OR, i presume you are using the 40 psi switch; what about the 55 psi switch that might catch dips a little sooner?

[AZ986S]

Originally Posted by The Radium King

when we are dealing with drops over fractions of a second, the time for the pressure sender to detect and open a valve is significant. if the only downside to having the valve open all the time is potential depletion of the pressurised oil supply, then using an accelerometer to open the valve in an anticipatory basis is a good compromise. OR, i presume you are using the 40 psi switch; what about the 55 psi switch that might catch dips a little sooner?

I thought about using the 55 psi pressure switch. I think the issue is that the oil pressure would be mostly bellow that, so in effect it would be always open. Today I installed a manual pressure switch "bypass" toggle switch so that I can keep the valve always open when needed. I will test that next weekend at AMP again, this time with PCA. I will set the Accusump Air pressure at 15 psi. This should give me 1.5 qts in the Accusump @ 60 psi, then 1 qt @ 30 psi, so about 0.5 qts to play with in real terms. If you start with 30 psi, the starting volume is 1 qt @ 60 psi, and @ 30 psi, it becomes 0 (empty). In theory, the response time is quicker at higher air side pressures, but you also start with less oil.

[AZ986S]

Was at AMP yesterday with the PCA group and logged some more data with and without the Accusump Bypass switch. This is a switch I installed to be able to keep the solenoid valve open, effectively bypassing the pressure switch.




The first session is from a few months ago with NASA at the same track, but with the NAPA Gold 1042 oil filter. The last 3 sessions are from yesterday. I turned on the Bypass switch only for Session 2. I did a fresh oil change with 10 qts of M1 15W50 prior to yesterday's event. I also increased the Accusump air preload to 15 psi from 7 psi previously.

Very similar numbers for all 3 session yesterday, with and without the Bypass switch. BUT, the interesting thing is that the Accusump did not trigger at all during sessions 1 and 3 with the bypass switch OFF. Looking at the pump pressures, it looks like the pressure did not go low enough (35 psi) to trigger the Accusump. The only possible explanation I see for this is that the oil level might be higher with the increased air side pressure. This pushes more of the total oil volume in the sump and less in the Accusump. The electronic oil level gauge was showing 1 bar above full with the Accusump partially empty. Either way, I am happy with the performance of the oiling system yesterday with the lowest VC pressure at 29 psi.

Next event is at Bondurant with NASA and I will collect more data with the bypass ON and OFF. My belief is that keeping the bypass ON with normal oil levels should help reduce the oil pressure drops.