Turbo oil feed restrictor size?
11-25-2013 | 08:13 PM
#1
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Joined: Aug 2011
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From: Portland, OR
Turbo oil feed restrictor size? Amazon screwed up and sent me two of these from two different vendors.
The restrictions are different sizes. One about twice the other.
What is the preferred size?
Ron
The restrictions are different sizes. One about twice the other.
What is the preferred size?
Ron
11-25-2013 | 08:28 PM
#2
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Ron-You definitely want a restrictor. I went through all kinds of issues when I was told by Precision NOT to run one. Anyways. I was running a .060 when I was running a stock oil pump and no issues. I now run a High Volume oil pump and oil was getting through the turbo. Stepped up to a .035 and issue went away. I would start with a .060 and see how it does.
11-25-2013 | 11:51 PM
#6
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Well I can tell you what happened to me and I am pretty sure I am not the first. I believe this was an issue with quite a few people.
I bought a set of Precision 62/62's. Only a couple months passed and the turbo's went out. I sent them in and was told I was NOT getting ENOUGH OIL to the turbo's. I was using a -4 feed and -10 drains. So I was told to go to a -6 an off the feed and then to a Y fitting NOT a T fitting and run the -4's. Well two months later ******* thing goes out again. Keep in mind that its's $500 for a rebuild. I kept being told that something was not right in my oil feed or oil drain.
This is where the ON3 turbos come in. I figured if I had something set up wrong that I would use some cheap *** **** instead of ruining some high dollar turbo's. I get my ON3's and they look better, are better packaged and am told to run a restictor. Completely the opposite of what Precision told me. I throw the turbos on with the restrictor and no issues what so ever. When I up graded to a high volume pump I got some oil through it. Stepped up to more of a restictor and smoke went away. I have had my turbo's for over a year now and hasn't missed a beat.
So this is what I learned. The turbo's need very little oil to work and the drain back must have no restrictions going back to the pan.
FWIW almost everyone runs some type of restrictor on the oil feed of some size. I think starting with a .060 is a good starting point. If you get some smoke coming out of the exhaust so you know some oil is getting through, then step up to a different size. Just my opinion based on real world experience. Hopefully, some others will chime in.
I bought a set of Precision 62/62's. Only a couple months passed and the turbo's went out. I sent them in and was told I was NOT getting ENOUGH OIL to the turbo's. I was using a -4 feed and -10 drains. So I was told to go to a -6 an off the feed and then to a Y fitting NOT a T fitting and run the -4's. Well two months later ******* thing goes out again. Keep in mind that its's $500 for a rebuild. I kept being told that something was not right in my oil feed or oil drain.
This is where the ON3 turbos come in. I figured if I had something set up wrong that I would use some cheap *** **** instead of ruining some high dollar turbo's. I get my ON3's and they look better, are better packaged and am told to run a restictor. Completely the opposite of what Precision told me. I throw the turbos on with the restrictor and no issues what so ever. When I up graded to a high volume pump I got some oil through it. Stepped up to more of a restictor and smoke went away. I have had my turbo's for over a year now and hasn't missed a beat.
So this is what I learned. The turbo's need very little oil to work and the drain back must have no restrictions going back to the pan.
FWIW almost everyone runs some type of restrictor on the oil feed of some size. I think starting with a .060 is a good starting point. If you get some smoke coming out of the exhaust so you know some oil is getting through, then step up to a different size. Just my opinion based on real world experience. Hopefully, some others will chime in.
11-26-2013 | 01:28 AM
#7
I just have a -4 line straight from the oil bypass to the turbo with a 90*. I have oil in my DP, but it only started after I put the crankcase evap kit on, so I know its only getting oil from there. Its a precision 7675. Maybe they have bigger journals? Idk man, I know a ton of people that have never had issues running just a -4 feed, and I've done that with both turbos I've had, no issues. Maybe I'm lucky?
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11-26-2013 | 10:47 AM
#13
Most AN 10 fittings i've seen are to small ID wise. Limiting the supply isn't the best option IMO.
I'd go with the turbo manufacturers specs. They call out supply line size and pressure. Also drain line size. From what I've seen most peoples drain is to small. Restricting the supply is a crutch for a small drain IMO and may lead to other problems down the road. (may not!) I used the holset specs on all my turbos and have never had a drop of oil in a down pipe and never had a failure on the 15-20 turbos I've run over the years.
Measure the ID of the drain on your turbo... Mine was 20mm
Then measure the ID of an AN10 fitting. My -12 fittings were only 15mm ID. Not sure how small the -10 fittings are!
Heres a couple I made....
I'd go with the turbo manufacturers specs. They call out supply line size and pressure. Also drain line size. From what I've seen most peoples drain is to small. Restricting the supply is a crutch for a small drain IMO and may lead to other problems down the road. (may not!) I used the holset specs on all my turbos and have never had a drop of oil in a down pipe and never had a failure on the 15-20 turbos I've run over the years.
Information taken direct from the Holset service manual for the HX35/40:
The oil inlet pipe should be 9.5 mm [0.375 in.] bore minimum and the oil drain pipe should be 19 mm
Oil return pipes are permitted to decline at an overall angle of not less than 30 degrees below horizontal. All turbocharger applications require a pipe of internal diameter greater than 19 mm which has integrated connectors. To ensure oil drains into the engine under all operating conditions, the return connection into the engine sump must not be submerged and the outlet flange of the turbocharger must be 50 mm above the maximum oil level of the engine sump pan.
Maximum permissible operating pressure is 500 kPa (72 lbf/in2) although 600 kPa (88 lbf/in2) is permitted during cold start up. Under idling conditions pressure should not fall below 70 kPa (10 lbf/in2).
15. Recommended oil flows for the turbochargers are 2 litre/min at idle and 3 litre/min above maximum torque speed.
The oil inlet pipe should be 9.5 mm [0.375 in.] bore minimum and the oil drain pipe should be 19 mm
Oil return pipes are permitted to decline at an overall angle of not less than 30 degrees below horizontal. All turbocharger applications require a pipe of internal diameter greater than 19 mm which has integrated connectors. To ensure oil drains into the engine under all operating conditions, the return connection into the engine sump must not be submerged and the outlet flange of the turbocharger must be 50 mm above the maximum oil level of the engine sump pan.
Maximum permissible operating pressure is 500 kPa (72 lbf/in2) although 600 kPa (88 lbf/in2) is permitted during cold start up. Under idling conditions pressure should not fall below 70 kPa (10 lbf/in2).
15. Recommended oil flows for the turbochargers are 2 litre/min at idle and 3 litre/min above maximum torque speed.
Measure the ID of the drain on your turbo... Mine was 20mm
Then measure the ID of an AN10 fitting. My -12 fittings were only 15mm ID. Not sure how small the -10 fittings are!
Heres a couple I made....
Last edited by Forcefed86; 11-26-2013 at 07:44 PM.
11-26-2013 | 10:54 AM
#14
Yep...
Seems to me people with oil problems have other issues that need addressed... Including, and more then likely, poor drain size, angle, etc...
Out of Precision (3), Turbonetics (probably 10), and multiple Borg warners... NEVER had a problem with a -4 line and 12 return...
Seems to me people with oil problems have other issues that need addressed... Including, and more then likely, poor drain size, angle, etc...
Out of Precision (3), Turbonetics (probably 10), and multiple Borg warners... NEVER had a problem with a -4 line and 12 return...
