Almost new T04E/K26 turbine is slacking

[diesel des]

I have 2 gt30R, one an a seat 1.8T and the other on the engine for my urq. Only one of those engines has ran yet and it has been fine with no restrictor.

Way do people think that it is only VW audi engine that make high PSI oil pressure? On a ford cosworth with a GT30 71R WG we have its oil feed "T" into the oil pressure point on the block The gauge reads upto 100 PSI over 6 bar on that same "t" with NO restrictor on the turbo. It is Fine....

Have a look at your Gt XXR turbo. You will see how restricted the oil inlet is where the small JIC fitting connects. The restrictor is in there.

Again, this is only my experience, make of it as you will. But i would never and will never run a restrictor on a garrett thrust turbo...

[diesel des]

Ok here is some info from HOLSET them selves. Garrett thrust bearing turbos are similar in there structure and so similar numbers apply. I read similar stuff in a garrett PDF but cant find it now. But basicly upto 88psi is ok for short bursts...

[Ross]

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've just fitted a GT3071R, thus I've looked at this thread with some interest. I noticed that the oil inlet looked pretty narrow but it was no where near as small bore as the oil restrictor. So I imagine it would flow some pretty hefy pressure. Particularly as Garrett (see above) advise that the oil is restricted depending on the nature of the engine's oil pressure, i don't think they would build in a restriction. Again, if it was built-in surely they would not advise that an oil restrictor is used?

Additionally, Garrett state that 40-45psi is the max that the turbo should see; this equates to approx. 3bar which is less than the 5bar that I see. So I think leaving it unrestricted is going to impede on the performance and exceed the pressures that it is designed to be used with.

That said... i think id rather give it a few PSI more than recommended that a little too less. Though BBs are more durable in oil-starved situations, there's always gonna be a drop in pressure as temps rise. As the pressure drops to more like 50-60psi under load when hot, that would suggest that any restriction would be minimal. I would be very interested to know what oil pressures are obtained from the 034 resitrictor i have, as i seem to remember it's in the 15-25psi range which would be fine for low-rpm use but not good once she starts singing!

Any more 'official' info/stats?? As I'm sure for every one that's ran with no restrictor for 100,000 miles, there's gonna be someone that's done the opposite. In this instance, I'd rather know what the manufacturers of the BB cartridges advise!

Cheers
Ross

[Jamo]

I've posted about this before Ross, it's on the 034 website the restrictor.

It's there to reduce oil pressue as the BB turbos require low oil pressure.

Unrestricted the oil due to the pressure blows past the seals.

This is from other garrett BB turbo owners

To clear this up once and for all i'd advise you speak to Corey as 034 sell the restrictor it must be deemed necessary

http://www.034motorsport.com/product...roducts_id=442
A Garrett GT ball bearing center section only needs 20-30 psi to lubricate effectively. Many motors produce oil pressure in excess of 100psi, often forcing oil past the shaft seals, causing smoking problems.


An oil restrictor will drop pressure levels to the appropriate level, alleviating smoking problems and ensure long-lasting, well lubricated bearings.

Recommended for ALL Garret GT Turbo installations, also converts the tricky inverted flare inlet to a simple -4 AN inlet.

[Jon441cc]

I've just fitted a GT3071R, thus I've looked at this thread with some interest. I noticed that the oil inlet looked pretty narrow but it was no where near as small bore as the oil restrictor. So I imagine it would flow some pretty hefy pressure. Particularly as Garrett (see above) advise that the oil is restricted depending on the nature of the engine's oil pressure, i don't think they would build in a restriction. Again, if it was built-in surely they would not advise that an oil restrictor is used?

Additionally, Garrett state that 40-45psi is the max that the turbo should see; this equates to approx. 3bar which is less than the 5bar that I see. So I think leaving it unrestricted is going to impede on the performance and exceed the pressures that it is designed to be used with.

That said... i think id rather give it a few PSI more than recommended that a little too less. Though BBs are more durable in oil-starved situations, there's always gonna be a drop in pressure as temps rise. As the pressure drops to more like 50-60psi under load when hot, that would suggest that any restriction would be minimal. I would be very interested to know what oil pressures are obtained from the 034 resitrictor i have, as i seem to remember it's in the 15-25psi range which would be fine for low-rpm use but not good once she starts singing!

Any more 'official' info/stats?? As I'm sure for every one that's ran with no restrictor for 100,000 miles, there's gonna be someone that's done the opposite. In this instance, I'd rather know what the manufacturers of the BB cartridges advise!

Cheers
Ross

Couldn't of put it better myself

[Corey]

To clear this up once and for all i'd advise you speak to Corey as 034 sell the restrictor it must be deemed necessary

Said it before but I will say it again.

Garrat recommend the restrictor, 034 recommend the restrictor and I recommend the restrictor.

HTH's?

Do we need the science bit (I wonder if Jennifer ANiston would mind coming across flicking her hair about a bit?)???

[Corey]

And to quote from Nate (of 034 fame)

The restrictor isn't required in all applications on the thrust bearing turbo's. Many people are fine w/o it. However on some motors with exceptionally good oil pressure you can start over-flowing and spewing out the seals.

Also keep in mind that these should be setup on a per-application basis. There is no one rule that will work for every setup out there. The drain line and turbo angle have as much to do with the restrictor needs as oil pressure and flow. I need them with the oil pressure on my v8, for instance. Even with good drains I would get some oil blow-by past the seals.

As for the BB turbo's I've yet to see one on an automotive app that didn't require a restrictor...

BB turbo's need the restrictor as stated, TB's it's a grey area, personally I would (and do).

[diesel des]

Mhhhh Jennifer ANiston ........