Originally Posted by YellowDogSVC
something doesn't seem right but maybe excavators are different on the aux circuit than skid steers. I've put flow meters on several skids to see the flow/psi at different rpms and watch pressure spikes, flow drops, etc. Most of the time the machines came stock out of range or on the low side. Same thing for RPM range, i've seen several machines not make enough rpms on the motor.
The hydraulic formula assumes 100% efficiency. We all know that's not the case at the quick couplers and from my experience, manufacturer rated flows and psi are off at the quick couplers, too.
I try and have each machine I buy tested before I put it in service especially when I am going to run high flow attachments. Out of about 8 or 9 skid steers, only one was set within the spec range but it was on the low side.
Why should you lower the rated flow because of a restriction in the connection? The manufacturer rates the machines with no restrictions. It's up to the owner to take advantage of it.The Aux circuit is electronically adjustable on most all of the new min ex's. The ones that are not it is easy to turn them up to max flow. The only other thing is to check the relief pressure on the aux circuit. It is usally less than the main pump relief. I also verified my machines flow with the cutters rpm.