carlos8

Hi guys, Recently I swap my SC34 for a 5831MFS, I left the .065 restrictor and the dam thing it's spiting oil to the hot housing.

I now from the SC34 the bearings are a SH!!! to found, But given this turbo is almost new.

It's worth take it to turbo center and replace just the seals and rebalance it?

-3 an Feed line w .065 restrictor
-10 an Return no kink
Bought it NEW in December 2014.

viper_boy403

iTrader: (1)

What's your oil pressure like?

TheShodan

iTrader: (14)

The older SC series parts are Garretts and were easier to find. For the 5831 series, you have to send it to Precision Turbo & Engine. You won't find parts for them in PR.

As viper_boy403 asked. how was the CHRA oriented, and what is your oil pressure at cold start?

carlos8

It's completely Vertical, Feed pointing straight to the hood.

85 psi at cold start.

In addition to the restrictor a 90* elbow will help with oil control.

TheShodan

iTrader: (14)

Was it an actual feed restrictor? Or was it was one of those plate styled restrictors found on eBay? That makes a bigger difference

If you can, post the type of restrictor this was

KevinEF7

Does it matter how the restrictor is formed?? Be it a plate style or a fitting with a flared end and a tiny hole? As long as the hole is the proper diameter Im curious if it would make a difference

carlos8

1/8" NPT x -3 an Normal fitting, inside taped with a weber jet. Drilled with a #52 drill .064"

https://honda-tech.com/attachment.ph...1&d=1428598195

https://honda-tech.com/attachment.ph...1&d=1428598195

carlos8

I also have this one from eBay .035 drilled to .060"

https://honda-tech.com/attachment.ph...1&d=1428598751

TheShodan

iTrader: (14)

Yeah.. that's similar to the plate design, where it has an open hole up top and a restriction in the middle of the fitting. That may be a problem. Not as much as the plate, but pretty close.

You need the fitting that actually has the opening on Top.. not in the middle.

1/8thNPT to -3AN


1/4NPT to -3AN (mainly for Garrett oil cooled only turbo)


0.30" 7/16 -24 to -3AN (For GT and GTX, Forced Performance, and other DBB turbos)


You can even find others without going to an entire new feed line if you have -4AN which is what most other turbo platforms use

.060" JB restrictor 1/8NPT to -4AN

carlos8

Where do I find this restrictor? In -3 an only the Vibrant one is the most close to what you show.

https://encrypted-tbn2.gstatic.com/i...Q26Ju6ohUkn4RQ

The jets going in the top and with out jet is .060"

LightningTeg

ATP Turbo sells them

TheShodan

iTrader: (14)

Yes. It does make a difference. It's not just "the hole" that determines what restriction is being used, its where it is placed into the oiling system. You have 2 "pills". a .065", and supposedly a .030" for the ball-bearing one. I've checked the pill size of the .030" pill, and its actually .038", AND its not the right thread pitch for Garrett Ball-bearing setups (those use 7/16 -24 size) Not horrible, but not great.

What turbo users have to realize is that a restrictor's purpose is to help regulate oil pressure into the oil channels of a turbocharger. What many of these Plate and mid-line restrictors do is they have an empty pocket within that fitting or flange that fill with oil and force itself through the smaller hole.

The problem with that configuration is that the oil pressure that fills these channels through that midline hole is reduced and not regulated at the lower oil pressure, so that it is steady enough to stream in, whether the car is at 75psi of pressure (cold start), or 20psi of pressure (warm idle). When you use these other types of restrictors, they more or less "drip" into the oil inlet at the point where the hole is drilled inside the plate.

That also means that the oil pressure fluxates as oil pressure at the line changes from cold start or WOT to warm idle. This fluxuation is what causes oil starvation problems within the turbocharger, because the channels aren't constantly filled with oil at the proper reduced rate.

That's why you don't put them on back of the oil sending unit or at the oil sandwich itself, as it can cause the same problem.

It can work, but the problem is that it is aluminum and is prone to leak and even strip into the steel threads that go into the turbo inlet. I just saved a GT3071R last week from the same issue.

I recommend going here for the proper restrictor. They even ship it USPS flat rate. You would use the pull down menu to select the correct one.

B&R Fittings.

TheShodan

iTrader: (14)

People think this fits, but its not the same

1/8th Male to 1/8th Female .065" restrictor

You would have to make this to work with the above

Straight 1/8thNPT to -3AN.

The male part of the 1/8th would have to be at the bottom going into the oil inlet, then the other 1/8thNPT to -3AN would fit on top of it. Lot of work, when you can simply get ONE piece from B&R fittings or other companies.

carlos8

Thanks, TheShodan. Already place the order with B&R.

carlos8

Received today the .060" B&R restrictor.

Before install it I made a small test: In a 1/8" bronze Tee, I put my actual restrictor on top and a 1/8 nipple on bottom and a 100 psi gauge in the middle. At cold start I see 50 psi at the gauge (after the restrictor).

Going to perform the same with the B&R.

What is the ideal pressure to the turbo?

TheShodan

iTrader: (14)

The journal bearing turbos are not as "picky" about the exact amount of oil pressure being delivered like the ball-bearing Garrett. From the GT28-GT35R, those typically want a steady pressure of about 22psi or so, but they can work fine at 15psi.

The journal bearing turbochargers (I'm talking Garrett specifically, but this can apply to Precisions) are a bit more forgiving, as the opening is slightly larger, and you'll have variance from the oil pump. A range of about 30-40psi range is pretty good. Even though the car may idle where your gauge may read lower than the "ideal" range, the point is that this allows for that range to happen without big fluctuations in oil pressure from the "pooling" method your previous ones do.

Make sure you add a little oil into the inlet before hooking it up. DO NOT use Thermal paste or sealant tape on the fitting itself. Its tapered at the end, and since its made of steel and not aluminum, you won't have to worry about leaks.

Putting thermal paste/sealant or other chemical may break off and obstruct the oil inlet causing oil starvation and damage.

Good luck. If its still not right, there may be other issues, but you've at least eliminated one of them with this..

carlos8

TheShodan: I cleaned the exhaust housing and installed the B&R .60" restrictor. The pressure still almost to 50 psi, but in the 5 minutes I leave the car on, no smoke so far.

When I went to install the restrictor without the TEE and gauge, The inlet hole was filled with oil ( the engine was shut down less then 1 minute). I just cleaned a little with a shop towel and install the restrictor. It always is empty, but this is the first time I open it after shutdown the engine.

Is this normal or the feed hole is suppose to be empty automatically after shutdown the engine?

Thanks, sorry for my English if you need more elaborated LMK.

TheShodan

iTrader: (14)

That's 50psi at the line itself, not at the actual inlet where oil is "squeezed" through the restrictor hole. The point of the restrictor is to regulate oil pressure at the turbo inlet, not anywhere before it. So your gauge will still read the same. that's normal.

What's not normal is putting the restrictor anywhere other than the turbo itself. If put to the back of the oil feed line within its path, and oil pressure really drops along the line of the turbo, it will only allow reduced amount of oil along the path and "dribble" into the oil inlet.. Once again, Oil starvation

You WANT oil in that inlet feed hole of the turbo..That's a GOOD thing, meaning that there is still pressurized oil that already filled the oil galley of the CHRA, and didn't pool into the internal plate of your old restrictor, that would just "drip" down into the actual CHRA inlet. You want that filled with oil at the top, so please STOP CLEANING IT! .
Those small drips that came from your old mid-plate style restrictor are not enough to fill the oil inlet channel, especially during shut down.

Basically, the turbocharger is running dry during your shut downs because oil is not cooling the turbine shaft as it continues to slow down in rotation. Remember, after shut down, for a few seconds give or take, your shaft is still spinning at over 10,000rpms and decreasing .... during that time, you're running it dry with the old restrictor you have... that leads to oil starvation.

Imagine you doing that to your engine. Revving the engine at 10,000rpms on a race, then shut the car down fast while the rotating assembly is still active. Next thing you know you've glazed a bearing due to oil starvation. Crazy, right?!?! Same principle applies here.

Starvation and turbine shaft damage occurs most when there's a sudden loss of oil pressure at the inlet hole and the turbine shaft is still spinning relatively high (about 50,000rpms) .. The best example I can give you: You're a drag racer at a track. You're on slick tyres and perform a staging burnout.... But your car shuts down after the burnout (maybe you forgot to put it in neutral after your burnout, or it cuts due to too much fuel.. or whatever).

When that car shuts off fast from this burnout, (for the sake of argument, you don't have an electric sump) , the oil pump stops pumping oil... which means its not getting to the turbo... which typically is still spinning at 50,000rpms.. even if some still "trickles" in, the turbine shaft is basically running DRY. Do that enough times, especially if its a Journal Bearing turbo, its not a matter of if, but when that unit will destroy itself from starvation.

Actually no, not really. It doesn't really control oil flow in the same respect as the oil return line scenario.

No worries. Just make sure you air out the oil inlet channel, and do not use a red oil rag in that inlet. the loose cloth fibers will interfere with the oil inlet. Even a blue shop towel is better.

Turbo Guy Code "Protip" : DO NOT USE SILICON SEALANT, RTV, OR THERMAL TAPE ON THESE STEEL RESTRICTORS. These fittings use a tapered end when screwing it into the inlet, they don't need it, and you can inadvertently clog that inlet with that stuff. Aluminum fittings using these sealants is normal, as they expand at a different rate than the iron alloy CHRA of the turbo. But not these steel fittings don't use anything to seal these up. That's why we use them over the Vibrant ****.

Good luck.. Hope its working out for you.

carlos8

Thanks, for the INFO and tips. All the doubts are cleared now!