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Oil restrictor plate for turbos

Jerd

Active member
Joined
Mar 1, 2008
Location
Vancouver WA
Im confused... When you buy an oil feed plate for a t3 type turbo they come with this tiny ass little hole and a -4 an feed. Supposedly this is to keep the pressure down in the bearing and is meant to make your turbo last longer and not burn oil. :wtf: "flow not pressure"

I have seen so many people feed oil lines strait into the turbo with a 1/8" npt an fitting. And i myself bought the plate and laughed at the stupid hole. I drilled it out. :-( Now im thinking not such a good idea.

Now that i have done a little reading about it, and concerned about drilling mine out i did some searching.

I stumbled upon a short conversation on vwvortex about how ebay turbos are splendid and work amazing ONLY IF YOU RUN A OIL RESTRICTOR PLATE.

Got me thinking.... There are people who get ebay turbos and go through 3 of them and they are all ****. Then there are people who buy one and they last 50k or more.

Are the people who are forced to try more than one, not running a restrictor plate? and the people who buy one, are they running a restrictor plate???

Is this the key to ebay turbo success? Do i need to get another restrictor plate and NOT drill it out??? I have noticed oil in my intercooler pipes but i figured it was from the pcv. My turbo is an AiResearch 63/42 t3 and i dont want to kill it. And im interested in upgrading to a .50 trim ebay turbo and dont want to kill it either.

This is the restrictor im talking about:
http://cgi.ebay.com/ebaymotors/T3-T...ies?hash=item518cb174ca&_trksid=p4506.c0.m245


EDIT: more oil restriction products.
034
OilRestrictor1.jpg

CI motorsports
garrett%20ball%20bearing%20center%20section%20upgrade-06.jpg


More here...
http://www.gt3turbo.com/Merchant/home.php?cat=383
 
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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.
 
No, my ebay turbo is fed with a -3 line and has put up with some abuse. The drain is more important than the feed imho. I think the ebay turbos get a bad rap because people who have no clue buy/install them improperly.
 
Oh... well now i just feel stupid.

will a factory t3 flange drain tube with some 5/8th hose on it suffice?

And im running -4 as a feed.
 
Well im not telling stories, my ebay turbo is still alive and i have no restrictor. My oil return line is -10 AN.
 
I don't know about the eBay specials, but the Garrett T25, T3, Mitsubishi TD04, and the TD04-HL has built in restrictor inside the center bearing housing. DO NOT use a oil restrictor on those.
 
I don't know about the eBay specials, but the Garrett T25, T3, Mitsubishi TD04, and the TD04-HL has built in restrictor inside the center bearing housing. DO NOT use a oil restrictor on those.
Oh sweet so my turbo already has one?

Well im not telling stories, my ebay turbo is still alive and i have no restrictor. My oil return line is -10 AN.

Oh i know, and you beat the **** out of yours. Im fallowing your build close because i would love to see how long it lasts.
 
Volvo used T3 , TD04 and TD05 based turbos for about, what, 20 years with no restrictors on the oil feed lines?

They last 100,000 miles easy. What does that tell you?
 
A restrictor on a journal bearing turbo can reduce spool time. You're obviously reducing the oil volume in the center section, so turbo life may or may not be impacted. I think datalogging boost onset with some different restrictor orifice sizes is worth trying, just to see how much you can actually pick up.
 
I remember when I busted my turbo.
I used to use a rb20det ball bearing turbo, then I swapped to one from a vg30det journal bearing.
I used to old rb20det banjo fitting. (During aseembly, I didn't realize it had a restrictor orific hole built-in, tiny hole) and after about 3 months, the turbo died. Look back, realized the journal turbo had a full sized hole. (But I didn't worry too much, rb25 or vg units are 30-40bucks from the jap wreckers.)

Now I have full hole... 2 years past and the turbo is still as good as day 1.
 
TDO4-HL turbos actually have a restrictor built into the oilfeed on the turbo body.
So do most...if not all Garrett BB GT series turbos IIRC. There's one built into/threaded into the body of my GT35R. But I'm still going to run another. Oil pressure in our redblocks doesn't usually get up too high so there's really no need to run a restrictor if it's not necessary on a journal bearing. If say you're making on an average 80-100 psi oil pressure you definitely wanna run a restrictor so the seals stay happy. 40-50 no need on JB...might still want one on a BB though.
 
Are factory Volvo turbos JB or BB? (I am still learning this stuff) I upgraded my feed line and installed one of the AN plates onto the turbo (factory Garrett T3). I drilled out the hole thinking, "why would I want to restrict oil flow?" But now I am wondering if I made the wrong choice.
 
Are factory Volvo turbos JB or BB? (I am still learning this stuff) I upgraded my feed line and installed one of the AN plates onto the turbo (factory Garrett T3). I drilled out the hole thinking, "why would I want to restrict oil flow?" But now I am wondering if I made the wrong choice.

journal bearing.
 
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