I keep hearing about this when reading about turbos...

So when would you need one?

// FI FAQ doesn't explain the need for one.
////HT search function blows *****..

 

when the feed line to your turbo has more than 30lbs of pressure, or if your stuff smokes...

 

Journal bearing turbo need restrictor?

 

i was told not to run a restrictor with my SC61

 

i would say ALL turbo's need to run a restrictor....hondas put out 70+ psi of oil pressure, a turbo needs around 30psi....

 

good question i was wonderin g the same.. i have a garrett t3/t61 and i was wondering the same thing.. and where do you get a restrictor at

 

This is NOT advisable, considering that the LINE actually runs a different pressure that what people see with a guage at the block.

For a honda application using a -3AN line from the oil sending unit on the block, on a journal bearing turbocharger, for the SC61 or similar, DO NOT RUN A RESTRICTOR.

 

your telling my the -3an line see's less pressure than my 1/8" id gauge line? i have them both coming off the same tee, coming from the same source. how is that possible? not saying your wrong, but would like a little more explanation please. my gauge see's around 75-80psi at wot...

 

I see more than that coming from my gauge where my feed is, I am in your shoes I dont see how the line will see less pressure coming from the same port.

I guess it really depends on the resistance inside the turbo, which I am pretty sure is low and does not allow the turbo to see that kind of oil pressure.........

 

I'm looking at the resistance in the cartridge. At WOT, that's fine, but what I don't want people to confuse is that the oil pressure at WOT is going to keep that layer of oil needed to balance and lubricate the turbo. When people are using "restrictors", and don't know what ID the apeture is, that can get dangerous. -3ArmyNavy, converts to something like 1/8th. (boy my math can get bad).. But you can't say to just use Oil restrictors on ANY application. that's a horrible general rule of thumb.

 

Well, I used GARRETT t3/t4 60-1 with oil feed size -4
So Do I have to use an oil restrictor?

 

I run an oil restrictor. Most of the time turbo blown/leak oil is because it's getting too much oil pressure than needed. I still run a restrictor too with my -3 an feed line.

 

-4an line here with a restrictor on my sc61 with no problems for the last 10k miles.

 

Use a restrictor on ball bearing turbos. That's it.
Journal bearing turbos do not.

 

P1V1=P2V2: the result is smaller volume means higher pressure.

Please correct me if I'm wrong, but a smaller diameter oil feed line will see higher oil pressure.

I was recently told journal bearing turbo's "don't need a restrictor." But I've also read that oil pressure beyond 25psi is detrimental to the seals. Better to be safe and run a restrictor.

If anyone knows, empirically, the oil pressure a -3/-4AN line on a 1.6/1.8L honda sees, feel free to chime in.

 

a great way to run the correct oil psressure is get a adjustable oil restrictor through stealthmodeperformance.com which cost about 15 bucks then hook up a oil pressure gauge at the turbo. Then call the turbo manufacture and get THEIR psi specs. And tune the pressure. there problem solved!!

 

Too much arguing. -4ANs use oil restrictors on average, not a suprise. A lot of us here have done the -3AN lines from stealthmode, fast-turbo, inline pro, etc, for these kits for hondas for over 10 years. They use -3AN line no restrictor on Garrett Journal bearing Mid-frame sized cartridges..

Argue on if you must guys...

 

really the only way to know for sure is to check the pressure at the turbo, then check with your turbo manufacterers specs

 

x2

The way a -3an line has less pressure compared to the -4an line works in the same principle as using a restrictor, smaller diameter for the oil to travel in. The restrictor restricts the amount of oil traveling and reducing pressure.

 

Gas equations do not apply to oil; doubling your oil pressure does not halve its volume.

Not quite - a smaller diameter oil line will have a higher pressure drop, as it creates more restriction than you would have with a larger diameter line. So if the pressure at the pump is the same, you would have more pressure at the turbo for a large oil feed line.