Garrett GT series turbo oil supply
12-02-2011, 12:22 AM
#1
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Location: Bay Area
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Car Info: 05 Legacy GT Wagon 5MT
Garrett GT series turbo oil supply
Hey baic, I have an avo 380 in my 05 lgt, which is really just a glorified stock location GT2871R...
Anyway, I currently run the stock hardline with the stock banjo bolt on the head (with the built-in filter removed), combined with the oil line and banjo supplied by AVO.
There appears to be no restrictor on either of these pieces.
AVO insists that the built-in restrictor on the GT-R series CHRAs (BB) is sufficient, but I was thinking of ditching the stock oil feed off of the head, and using a filter kit from infamous (http://legacygt.com/forums/showthrea...ns-173373.html) which caps the turbo feed, and instead pulls oil from the avcs.
Problem is, the stock turbo feed is restricted somewhat, while the AVCS feed is unrestricted despite running off of the same head feed.
The kit above is for the vf40 which has a different thread pitch for the feed, but the lines are -4AN, so I was thinking I could just use a fitting from ATP to make it work with my turbo.
The big question then is, do I use ATP's 0.035" restrictor or not? Based on my observations above, the larger size of the AVCS feed would warrant an additional restriction that normally wouldn't be required if I was running off of the turbo feed.
Anyone with a garrett GTxx[xx]R BB turbo experience care to chime in?
I'd really hate to do something stupid and end up with an expensive paperweight.
Anyway, I currently run the stock hardline with the stock banjo bolt on the head (with the built-in filter removed), combined with the oil line and banjo supplied by AVO.
There appears to be no restrictor on either of these pieces.
AVO insists that the built-in restrictor on the GT-R series CHRAs (BB) is sufficient, but I was thinking of ditching the stock oil feed off of the head, and using a filter kit from infamous (http://legacygt.com/forums/showthrea...ns-173373.html) which caps the turbo feed, and instead pulls oil from the avcs.
Problem is, the stock turbo feed is restricted somewhat, while the AVCS feed is unrestricted despite running off of the same head feed.
The kit above is for the vf40 which has a different thread pitch for the feed, but the lines are -4AN, so I was thinking I could just use a fitting from ATP to make it work with my turbo.
The big question then is, do I use ATP's 0.035" restrictor or not? Based on my observations above, the larger size of the AVCS feed would warrant an additional restriction that normally wouldn't be required if I was running off of the turbo feed.
Anyone with a garrett GTxx[xx]R BB turbo experience care to chime in?
I'd really hate to do something stupid and end up with an expensive paperweight.
12-02-2011, 09:12 AM
#2
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Car Info: 97' Dodge Cummins and an RSTI thingie
I'm not terribly experienced with legacies or garrett turbos, but look at the sticky on the BAIC main forum and call one of the shops. I'm sure they know, I know GST runs a garrett (or did) in their race car.
12-02-2011, 11:41 PM
#3
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Car Info: 05 Legacy GT Wagon 5MT
Well, the legacy is nothing special compared to any other 2.5 wrx - just another ej255, so I was wondering what other people with AVCS 2.5 motors do for their oil supply lines on garrett BB turbos...
Do other garrett bb kits reuse the stock hardline that feeds off the back of the head?
Everywhere I look online I find some people saying it's necessary to run the additional restrictor, and others saying the built in one is enough...
For reference, most (all?) Garrett GTxx[xx]R CHRAs have a built-in restrictor that looks like this, which the avo has, and I assume other Garrett BB based turbos do:
Maybe a better question is, given the nature of subaru oil pressures (fairly high from what I understand... 6 bar (~87psi) at the high end, 2 bar at idle), would an additional restrictor in conjunction with the built-in restrictor cause oil starvation to the turbo?
garrett's website says:
Am I just really paranoid and over thinking the whole thing?
Should I just throw a restrictor on it and shut up?
Do other garrett bb kits reuse the stock hardline that feeds off the back of the head?
Everywhere I look online I find some people saying it's necessary to run the additional restrictor, and others saying the built in one is enough...
For reference, most (all?) Garrett GTxx[xx]R CHRAs have a built-in restrictor that looks like this, which the avo has, and I assume other Garrett BB based turbos do:
Maybe a better question is, given the nature of subaru oil pressures (fairly high from what I understand... 6 bar (~87psi) at the high end, 2 bar at idle), would an additional restrictor in conjunction with the built-in restrictor cause oil starvation to the turbo?
garrett's website says:
Oil pressure entering a ball-bearing turbocharger needs to be between 40 psi and 45 psi at the maximum engine operating speed. For many common passenger vehicle engines, this generally translates into a restrictor with a minimum of 0.040" diameter orifice upstream of the oil inlet on the turbocharger center section.
Should I just throw a restrictor on it and shut up?
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