Jump to content
SAU Community

Recommended Posts

Hi Guys,

I just bought a second hand hks 2535 that I'm going to throw on my rb20. I am going to make some stainless lines and would like a definate answer on wether I need an oil restrictor or not.

I searched but couldn't find quite what I was looking for.

:domokun:

Link to comment
https://www.sau.com.au/forums/topic/200812-do-i-need-an-oil-restrictor/
Share on other sites

Hi Guys,

I just bought a second hand hks 2535 that I'm going to throw on my rb20. I am going to make some stainless lines and would like a definate answer on wether I need an oil restrictor or not.

I searched but couldn't find quite what I was looking for.

:(

Here is what the tech from garret sent me:

FAQ: Does my turbo require an oil restrictor?

Oil requirements depend on the turbo's bearing system type. Garrett has two types of bearing systems; traditional journal bearing; and ball bearing.

The journal bearing system in a turbo functions very similarly to the rod or crank bearings in an engine. These bearings require enough oil pressure to keep the components separated by a hydrodynamic film. If the oil pressure is too low, the metal components will come in contact causing premature wear and ultimately failure. If the oil pressure is too high, leakage may occur from the turbocharger seals. With that as background, an oil restrictor is generally not needed for a journal-bearing turbocharger except for those applications with oil-pressure-induced seal leakage. Remember to address all other potential causes of leakage first (e.g., inadequate/improper oil drain out of the turbocharger, excessive crankcase pressure, turbocharger past its useful service life, etc.) and use a restrictor as a last resort. Garrett distributors can tell you the recommended range of acceptable oil pressures for your particular turbo. Restrictor size will always depend on how much oil pressure your engine is generating-there is no single restrictor size suited for all engines.

Ball-bearing turbochargers can benefit from the addition of an oil restrictor, as most engines deliver more pressure than a ball bearing turbo requires. The benefit is seen in improved boost response due to less windage of oil in the bearing. In addition, lower oil flow further reduces the risk of oil leakage compared to journal-bearing turbochargers. 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. Again, it is imperative that the restrictor be sized according to the oil pressure characteristics of the engine to which the turbo is attached. Always verify that the appropriate oil pressure is reaching the turbo.

The use of an oil restrictor can (but not always) help ensure that you have the proper oil flow/pressure entering the turbocharger, as well as extract the maximum performance.

I hope this helps as I would hate for anyone to have to do what I am doing!!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • roof rail delete used to be a thing, they were made locally for a while too
    • I can get more photos of it here soon and I plan to make a thread detailing the process. I received the car this way and it sorely needs refinishing. That is probably the most appealing photo of it. Up close it is fading, cracked, and needs to be re-glued. Depending on their condition I'm on the fence between refinishing or making a new set.  Another angle hiding the pimples and razor pumps  
    • According to this thread the RS4V with build plate RC40 comes with the R200 diff @ 4.083 ratio as well (mine has said RC40 denotation). We may need to check if the axle stubs are the same pattern as well. The auto subframes have longer axles. However I think yours being a later Series 2 as well, we should have the same bolt pattern for the diff stubs. Unless your upgraded rear also has upgraded axles. Either way, I would not be opposed to pulling the covers to check so I can inspect that  fancy rear core  Also I don't have HICAS. I don't believe that should change things but I hope the people here with heaps more experience than me can correct me if I'm wrong   Let me know if you want to attempt to make this work and I can get some pictures of mine from under the car. 
    • It's not that straightforward. For example I have had this code because my ignitor/power transistor wires were unplugged. It knows something is wrong but has no idea what it means. If you want to actually diagnose this I recommend following the service manual flowchart for code 21. Ohm out the harness, coilpacks, inspect the ECU, etc. And again, it's entirely possible for there to be no problem at all but if you're running a different coilpack it'll trigger the code because it doesn't like what it sees.
    • If it (the code) wasn't still current, it should have gone away by itself by now. No, nothing it 10/10. But it is quite likely. Everything else to do with the ignition could still be responsible (which is wires and connectors). The car is an old piece of shit now, so all the wires and connectors are also old pieces of shit.
×
×
  • Create New...