1G Which Size Oil Restrictor Off head For Precision Turbo

[Maddashimports-Matt]

I have a 92 Laser i'm putting a Precision Billet Wheel 5557 on. Engine has the balance shafts deleted. Want to run the oil supply off of the head if possible. Was wondering what size of a restrictor the garrett/precision guy's are running. Searched a few threads (Everyone being a 20g/16g/or 14b wanting a resrictor ran off the housing) so couldn't find a good answer. I've owned 6-1g, 1-2g dsm's but always ran MHI units off of the head and never had problems.

 

[mavericktsi83]

BB or JB?

 

[Spoolingaround]

You really should measure the oil pressure off the head before deciding on a restrictor size. The turbo probably has a recommend oil pressure range from the manufacturer. Other things will come into play too, like if you have oil squirters or BSE.

 

[Archer Fabrications]

Is it a new turbo? Air cooled? Have you talked to precision?

For my 6466 ballbearing, oil feed no restriction off the oil filter housing. -4 feed. Recommended by precision, no in line filters or warranty is void. The restrictor is built in to the CHRA, if it's an older garrett chra you will want to verify oil pressure, you should verify oil pressure anyway though.

 

[Maddashimports-Matt]

Turbo has 2000 miles on it. Journal bearing. Engine still has oil squirters and balance shafts are deleted. Engine is new and hasn't even been run yet. I'll try to email precision and see what they say about it.

 

[Spoolingaround]

I am never for feeding off the head. I think the OFH is a much better choice.

 

[Archer Fabrications]

Head feed is not consistant volume or enough pressure for journal bearing turbos.

 

[mavericktsi83]

You will want to use the largest return possible to make it live—this is a must. The key to setting up a proper drain is welding an AN fitting to the oil pan and enlarging the tiny OEM return hole to match. This will lessen the need for a restrictor, possibly resulting in no need for one and provide the best oil flow to your turbo. Insufficient drains do back-up and cause problems. I would def feed it off the OFH. Like others have mentioned every engine/setup is different and you owe it to yourself to measure what pressure you are seeing on your car. jusMX141 has a bunch of good posts on this subject with the additional details you’ll need.

I’ve used a Precision JB turbo in the past (2007) and I have found them to have very poor longevity when compared to the other options out there. I can’t comment on their more recent quality or changes, if any. If you get a chance to talk to Precision it would be valuable to know if they went away from their use of a steel thrust bearing as there have been a lot of thrust failures reported with their JB turbos. I have read users are having better luck with upgrading to a brass thrust. But in any case run it with high-zddp content oil and at 75 psi peak inlet pressure—I teed in an oil pressure gauge into my feed to check what’s going on and did not go with anyone’s “restrictor recommendation” as this can be costly guess. Good luck and keep us updated.

 

[Maddashimports-Matt]

Talked to Grant from Precision. Here's what he had to say, "We recommend the use of a -4AN feed line and feed fitting, not restriction.
We also suggest a -10AN (5/8" ID) drain line minimum. Suggested oil
pressure is 15-85 PSI, but more oil pressure can be used. It will be more
critical to make sure the crankcase ventilation and drain setup are correct,
the higher oil pressure you run."
Seems like a pretty big range in pressure. Thanks for the good info maverick.

 

[boost97gst]

I ran my 5558 JB 4AN unrestricted from OFH. You'd think it's brand new. Has ZERO play in/out or side.
The pressure range is fine. I would verify your oil pressure isn't too high off the OFH and just use that. That's just my opinion, i know plenty run off the head port with no problems.

 

[Archer Fabrications]

Talked to Grant from Precision. Here's what he had to say, "We recommend the use of a -4AN feed line and feed fitting, not restriction.
We also suggest a -10AN (5/8" ID) drain line minimum. Suggested oil
pressure is 15-85 PSI, but more oil pressure can be used. It will be more
critical to make sure the crankcase ventilation and drain setup are correct,
the higher oil pressure you run."
Seems like a pretty big range in pressure. Thanks for the good info maverick.

Grant is the man. Hes a dsm guy.

 

[Maddashimports-Matt]

Awesome thanks for the great info guy's appreciate it. I'll check the pressure as soon as i get the motor fired and keep ya posted. Should be fairly high being a new motor and all.

 

[mavericktsi83]

I ran my 5558 JB 4AN unrestricted from OFH. You'd think it's brand new. Has ZERO play in/out or side.
The pressure range is fine. I would verify your oil pressure isn't too high off the OFH and just use that. That's just my opinion, i know plenty run off the head port with no problems.

Cool. What is the manufacture date of your 5558? Steel or brass thrust? How many miles on it?

 

[JusMX141]

Feed from the filter housing, restrict as needed to get pressure to 75psi peak. You're better-off porting your filter housing or toying with the relief valve and using a drain the size of a fire hose than adding a restrictor to one of these turbos if you can avoid doing so.

That being said, oil it exactly how PTE tells you to....that way when it fails they can't come back on you and blame you for improper oiling- which is the #1 reason they'll deny any warranty claim.

 

[boost97gst]

Cool. What is the manufacture date of your 5558? Steel or brass thrust? How many miles on it?

I want to say i bought it brand new in 2013. Unsure of steel or brass. Mileage around 4300 on it. I know PTE isn't popular, guess it's their quality control, but i seriously have a turbo that,aside from normal rust, feels and spins like brand new.
It wasn't babied either. I pushed it as hard as it would go. I could only get at most around 33 or 34 psi out of it. Gotta think, i was using a .63ar dsm hotside. Ported 2g exhaust mani and heavily ported o2 housing but still, the hotside was a restriction. In t3 form i imagine it would put down it's advertised 59lbs/min. Possibly more.

Speaking, i gotta sell some damn parts pretty soon. Shit is piling up and it's actually worth money haha.
Good luck and listen to justin. he's justin and we're not. Dude builds turbos for a living i think

*EDIT: I also used the PTE drain kit. It's just a big ass fancy blue hose with AN fittings that cost a lot. Go with the largest drain you can fit with the smoothest transition to the pan and do NOT have the drain line dip below the pan hole. You want that oil ripping through there. The more the better, as long as the pressure isn't too high obviously. It cools the chra as well as lubricates the bearing. 4 feed, 10 drain and you're golden.
You're fine with no water cooling too. Just don't race it into your garage.

 

[bastarddsm]

I know everyone has differing opinions on this, but give that thing a firehouse worth of oil. Pte's tend to eat thrust bearings iirc, and a thrust bearing is way different than a radial bearing. A radial bearing will generate a hydrodynamic wedge and maintain it will very little supply. The thrust bearing on the other-hand is a much different animal, and it is oil thirsty.

Short story is, more oil is better than less, unless you like replacing hard parts. I'd rather deal with oil consumption than junk wheels and housings....

I know it's apples and oranges, but a vehicle I work on has an HX 60 on it. we have a -6 oil feel line to it right off its own stage of the drysump pump. We give it 80psi of oil pressure at full tilt, and run it very very hard. It operates in compressor choke always with a very aggressive billet wheel, and we make 1700hp on a 76mm turbo. 60psi boost, 140krpm shaft speeds. 4 seasons original bearings. No oil consumption.