# Power steering pump as turbo oil scavenge pump.



## dkveuro (Jul 23, 2002)

I am debating using a p/s pump as a turbo oil scavenger on an ABA in a Vanagon.
This list is what I found for flow rates through an A4 Audi p/s pump..
I presume the pressure limiter was removed.
800RPM = 2.68GPM.
1k = 3.35GPM
1.5k= 5.025GPM
2k= 6.7GPM
3k = 10.05GPM
3.5k = 11.725GPM
4k = 13.4GPM
4.5k = 15.075GPM
5k = 16.75GPM
6.5k = 21.775GPM
7k = 23.45GPM
7.5k= 25.15GPM
8k = 26.8GPM
8.5k = 28.475GPM
Beauty of this kind of pump is it is rpm controlled. Obviously oil volume and pressure is higher at elevated rpm as is flow due to viscosity changes through the turbo..
I am using 0W30 oil and my pressures are ........
Cold Idle 5+bar.
Warm Idle 2.5bar.
Any rpm over idle is 5+bar. I plan on using a restrictor in the oil line to the turbo depending on flow requirements of the turbo....anyone know ? 
Currently the turbo is from a 1.9 TD . Chosen because of the need for low rpm boost with max of 6 to 8 psi at 3500 rpm.
I am using the inter cooler from a 4.7 ltr NPR diesel engine, piped with overkill 3" aluminum tubing....primarily to reduce back pressure through the inter cooler.
Any thoughts on the durability of a p/s pump in this kind of application and should I use a cooler for the oil prior to the p/s pump?
Current oil temperatures when cruising at 3500 rpm is 210F at the oil filter and 170F and lower coming back from the front mounted oil cooler.
This is because of the 180c thermostatic oil controller between the oil pump and the engine..
I am about to do a flow test myself and see for a fact what the flow volume of a p/s pump is. ...although at present I know little about the real volume these pumps will flow.
Chime in anyone..all input will be considered along with any previous post links on this subject...I found none on a search in VWvortex.


_Modified by dkveuro at 11:41 AM 6-28-2009_


----------



## Fahrvergnugen (May 1, 2002)

*Re: Power steering pump as turbo oil scavenge pump. (dkveuro)*

Interesting thoughts here, I will intersperse my questions with your thoughts...

_Quote, originally posted by *dkveuro* »_I am debating using a p/s pump as a turbo oil scavenger on an ABA in a Vanagon.

So as a scavenger pump, it will literally suck the oil through the turbo? Why would this be helpful?


_Quote, originally posted by *dkveuro* »_
Any rpm over idle is 5+bar. I plan on using a restrictor in the oil line to the turbo depending on flow requirements of the turbo....anyone know ?

I think you would do well to talk to a reputable rebuilder to get some figures you might trust. 

_Quote, originally posted by *dkveuro* »_
Currently the turbo is from a 1.9 TD . Chosen because of the need for low rpm boost with max of 6 to 8 psi at 3500 rpm.
I am using the inter cooler from a 4.7 ltr NPR diesel engine, piped with overkill 3" aluminum tubing....primarily to reduce back pressure through the inter cooler.

While I understand the demand to reduce back pressure, I believe you will have an issue with air charge velocity. While that intercooler is plenty big, I think you will reduce spool-up. Why not use that G60 intercooler you have, especially since you aren't going to go more than a 6 or 7 psi?










_Quote, originally posted by *dkveuro* »_
Current oil temperatures when cruising at 3500 rpm is 210c at the oil filter and 170c and lower coming back from the front mounted oil cooler.

You mean F, don't you? 








You might consider an oil cooler after the install...


----------



## dkveuro (Jul 23, 2002)

*Re: Power steering pump as turbo oil scavenge pump. (Fahrvergnugen)*

Your points well taken. Yes...F, not C....late night brain fade. ( Post corrected.)
As you know, the engine sits at an angle of 50 degrees making the turbo oil outlet about 4 inches from the floor of the oil pan....the oil outlet being nearly as low as the oil level in the pan.
Extracting the oil via a pump in this position is mandatory.....my only problem is considering which pump to use...electric or engine driven.
This means constant speed or engine rpm ...with ability to change pulley sizes.
Pulling the oil out of the return pipe and making a slight suction on the turbo has no bearing ( no pun intended.) on the turbo oiling. It will stop oil overwhelming the turbo oil seals and then dump the oil into the engine.
Only consideration is the pooling of oil at shut down in the return line and pump.
Would rather it did not emulate a Martini 911 on re start .
Any pump used to scavenge a turbo will only get the oil that the turbo no longer needs. You need to be familiar with the layout of the center bearing assembly to realize the oil HAS to do it's job before returning to the engine, by what ever means.
I did, if you remember, run a 1.8ltr T2 with a Audi 5k KKK turbo for a few years returning the turbo oil to the engine by gravity alone....a drop of around 6 inches . Had no oil burning problems or smoking....Man, I wish I still had that van.
I think running an electric pump is OK for short duration but for day to day and vacation use it would be better to imitate performance engine builders in using an engine driven pump.
Current ball bearing turbo's require around 30 psi to the bearings. I have in the past used oil from the oil sender port through an oil line to lubricate the turbo hoping the restriction of the line alone would suffice to reduce over-oiling.....and that seemed to be the case.
The LARGE inter cooler just takes slightly longer to pump up as it acts like a buffer or accumulator....considerations of 'turbo lag' are not important in this application.
Retrospectively I should have used a 2 or 2.5" pipe....who knows, I may yet.
Being as the system already has a pre engine 180f shunt cooler installed ...fitting another is pointless.



_Modified by dkveuro at 11:41 AM 6-28-2009_


----------



## Fahrvergnugen (May 1, 2002)

*Re: Power steering pump as turbo oil scavenge pump. (dkveuro)*


_Quote, originally posted by *dkveuro* »_
Being as the system already has a pre engine 180f shunt cooler installed ...fitting another is pointless.


IE, you have an air to oil cooler in there now? If so, yes, that would be redundantredundantredundant...

Also, that turbo you have is a brass solid bearing sort, isn't it?


----------



## dkveuro (Jul 23, 2002)

*Re: Power steering pump as turbo oil scavenge pump. (Fahrvergnugen)*

It's a KKK K-24 iirc. New, balanced center assembly. Def' not ball bearing or ceramic balls.
They seem to last well over 100k in stock usage....it won't be driven that much.


----------



## Fahrvergnugen (May 1, 2002)

*Re: Power steering pump as turbo oil scavenge pump. (dkveuro)*

Agreed, I am sure it will be fine.


----------

