GT TURBO's on 4G63 INFO!!!

[bazeng]

Hi guys

I just thought I'd share this information with those with GT turbo's

For those who are running one, oil pressures must remain low. To ensure this if you are running the oil feed from the head, you must run a .125" restrictor (3mm)..... If you are running the oil feed from the oil filter housing, you will require a .8mm restrictor....

Have the restrictor as close to the turbo as possible!
a -4 line is usually used for the feed...

This info is only based on the 4g63..
Info sourced from dsmtalk, provided by forced performance...

Based on the oil pressures generated by the 4g63 which are
25psi @ idle
75psi @ 5000rpm
up to 100-110 psi at cold start and 7000rpm...

NOTE: Balance shaft removal will increase oil pressures

If you do not restrict the turbo feed, it will leak past the seals and you will burn oil out the exhaust....

Hope this will help those with GT turbo's...

 

[Jayz-1]

By GT turbos you mean GT30, GT35 etc?

From my understanding that the Garrett turbos have there own restrictor at the top of the core from the factory so that you didn't have to muck around with trying to work shit like this out?

Can anyone confirm the info from Forced Performance?

Thank you
Jason

 

[bazeng]

yep, I am referring to GT ball bearing turbo's

i've looked into mine and it doesn't look like it..
personally.. the restrictor would depend on too many things

ie.. oil pressure from different engines

4g63's are known for high oil pressures.. therefor the restrictor size of a 4g vs a sr would differ...

there are specifics that the GT turbo's require... the info above was tested and proven by forced performance..

slowboy also sell the restrictors..

so i am assuming its true
also i am having the exact same problems that are described when not using the restrictor...

i have already made mine and will test it out soon..


GT CHRA Ball bearing applications:

The body of the filter features a built in .8mm restrictor as recommended by Garrett for use with their GT25R, GT30R, GT35R cartridges. Garrett has recommended oil pressure specified for the oil inlet of the GT CHRA. The idle oil pressure at the turbo should be 9psi and oil pressure at 5000rpm should be 30psi. The .8mm restrictor will reduce an engine with 25psi oil pressure at idle, 75psi oil pressure at 5000rpm to these Garrett recommended pressures.

4G63 Specific info:

When using the FP4ANFilter on an oil supply line that originates at the filter housing on the 4G63 engine, the .8mm restrictor results in the Garrett recommened pressure at the turbocharger oil inlet. For 4G63 engines that feed the turbo oil off the cylinder head, the .8mm restrictor should be drilled out to .125. The normal 4G63 engine has low enough oil pressure at the head oil supply port that the .8mm orifice is not required. The filter element provides all the restriction needed to get the oil inlet pressure down to the Garrett recommended values.

 

[EVO-00X]

The normal 4G63 engine has low enough oil pressure at the head oil supply port that the .8mm orifice is not required. The filter element provides all the restriction needed to get the oil inlet pressure down to the Garrett recommended values.

Good find Bazeng. As stated, guys with GT turbos should be feeding from the head and dont need a restrictor as a filter will do...

 

[bazeng]

Here are some pictures

Hopefully I'll stop blowing smoke!!

 

[Jayz-1]

Got this off www.Turbobygarrett.com.au website...

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.

Interesting...
I don't ever see any smoke out my exhaust (but who knows if my cat is catching it all)

I think ill have to get an oil pressure gauge and find out what oil pressure I have, as my oil feed to the turbo comes off the the oil pressure switch down on the side of the block...

How much was it for the restrictor and tapping Baz?

Let us know how it turns out...

Thank you
Jason

 

[bazeng]

the hydrolics place around the corner did it for $30.00

just inspect the turbo, see if its leaking like mine (behind the turbine)

other problems i've heard of is lack of drainage..
the return lines should be as large as possible..
mainly experienced with HONDA's...
the stock vr4 drains i believe are big enough

 

[runuts]

This is the oil pressure documention direct from garrett. (As almost all engines have varying oil pressure, I would t-piece a pressure gauge after your restrictor to confirm the correct oil pressure)

 

[matress]

what's your oil drain line made up of baz man?

are they aluminium barbs or something?

did you have to port out the port on the sump for a bigger oil return?

 

[WRCVR4]

DAM Barry, that turbo is close to that engine mount :wink: