Pump Power Reduction
Pump Power Reduction
(OP)
I put together a stand alone oil system to feed a turbocharger and am having problems with the pump drawing too many amps(10A).
The system goes like this:
Turbo Outlet ->(3/8" Line)-> 1 Gallon Vented Oil Tank ->(3/8" Line)-> Pump Inlet ->(5/8" Line)-> Pump Outlet to Tee Fitting ->(5/8" Line)-> Turbocharger / Pump Outlet to Tee Fitting ->(3/8" Line)-> 1 Gallon Vented Oil Tank (to regulate pressure)
The pump is a brass/bronze gear style pump with a 12V DC motor driving it.
Would changing the line size help reduce the amp draw on the motor while maintaining a minimum of 20psi?
How much would thinner oil impact the power usage? I'm using some 10W40 I had laying around to run the test.
Will the required power become lower once the turbocharger starts spinning due to the oil having an easier path to flow?
The system goes like this:
Turbo Outlet ->(3/8" Line)-> 1 Gallon Vented Oil Tank ->(3/8" Line)-> Pump Inlet ->(5/8" Line)-> Pump Outlet to Tee Fitting ->(5/8" Line)-> Turbocharger / Pump Outlet to Tee Fitting ->(3/8" Line)-> 1 Gallon Vented Oil Tank (to regulate pressure)
The pump is a brass/bronze gear style pump with a 12V DC motor driving it.
Would changing the line size help reduce the amp draw on the motor while maintaining a minimum of 20psi?
How much would thinner oil impact the power usage? I'm using some 10W40 I had laying around to run the test.
Will the required power become lower once the turbocharger starts spinning due to the oil having an easier path to flow?





RE: Pump Power Reduction
True, they are going to the (vented) oil tank, but they are the most restrictive part of the flowpath.
Amps are high, but are you getting enough oil to the turbo bearings to keep them cool?
RE: Pump Power Reduction
How I have it set up the turbo bearings are getting 20 psi with plenty of volume, I think this is adequate for the journal style bearings. The problem that I have is that the pump motor is rated to run around 5 amp and it's running over 10 amps causing it to shut off due to heat after a certain amount of time. This would be unacceptable with the turbo installed on my truck and would result in ruining the turbo.
The way I found that the motor was running over 10 amps is that I put a 10A fuse in the line and it blew once the line approached 20psi.
I may just have to plumb an oil line from the engine and then use the electric pump to scavenge the oil back to the crankcase (very little build up of pressure in line) but I was hoping to do a stand alone setup to isolate the engine and turbo oil.
RE: Pump Power Reduction
RE: Pump Power Reduction
If I was really concerned about the pressure at the turbo I'd put a gage there.
Look what size line was adequate for a Corvair turbo fed at ~ 45 psi. I believe there was an orifice in the fitting at the Turbo to boot. Yhe line might have been a wimpy 3/16" as I vaguely recall.
http://upload.wikimedia.org/wikipedia/commons/e/e1...
RE: Pump Power Reduction
I was thinking that someone might say that my supply line to the turbo is too larger and that using a smaller line would reduce the amount of work required by the pump but this does not appear to be the case. I'll just have to plumb an oil line from the engine and use the pump I have to scavenge the oil back to the engine.
RE: Pump Power Reduction
Johnny Pellin
RE: Pump Power Reduction
RE: Pump Power Reduction
Therefore in essence your pump is simply pumping at too high a pressure for the motor you have got on it.
Your options are:
Reduce the pressure by your pressure control (tee fitting to tank), probably to about 10 psi. If you don't change anything else this will result in less flow through your turbo as more flow will just go via the pressure controller back into the tank.
Buy a bigger motor
Increase tubing size to reduce friction losses (only works if helps reduce pressure output from the pump but maintain flow through your turbo)
Reduce viscosity of fluid (which will reduce your friction losses, but unless you change the pressure setting that alone won't help much.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Pump Power Reduction