Garrett GT35R death

[Afroclipse]

So my buddies turbo is dead and I don't know why.

Here is a brief summary, 240sx blueprinted sr20 sleeved engine and all that nonsense, q45 throttle body, powerfc, 1000cc, aaahh etc.

Anyway against my advice to break in the motor with a smaller turbo he decided to do it with the expensive 35r, so due to the lag(no tune yet) and poly engine and suspension bushings he only drove it about 100 miles give or take in a whole year. This week he pulled her out drove her for a couple days and he started to hear noises from his turbo, so I checked it for him wow, in and out, up and down, round and round, touch your toes everything. Its DEAD, so I checked the IC piping for oil, nada so lead me to oil starvation.

How much less oil goes into the BB units? after I removed his oil line I checked the oil flow and it was down to a narrow pour(restrictor) while my MHI is a gush. His restrictor is at the turbo, I thought it was supposed to be at the filter, would that hinder anything. Anyway your thoughts are appreciated as well as your knowledge on warranties and what not to say to garrett. Can really not rebuild garrett turbos?

[kahl23]

BB CHRAs can't be rebuilt, but Garrett does have a core exchange policy:
TurboByGarrett.com - BB Service

BB CHRA's also require restrictors, so it should have less flow than your MHI unit, which is journal bearing. Was he running a filter in the oil line? I've heard of turbos running fine before an engine rebuild, but then after the rebuild various tiny pieces of metal would work their way into the turbo and trash the bearings if there wasn't a pre-turbo filter. FP sells them for -4AN lines and there are also tons of other brands sold through places like Summit or Jegs. It sounds like that might have been the case here. Another possibility would be if he did have a filter and didn't check the element for clogs, which resulted in a clogged line, oil starvation, and then turbo failure. Hope that helped.

[Afroclipse]

without the resrictor it flows fine, ill check out the core exchange policy thank you, anymore thoughts.

[jusmx141]

Originally Posted by Afroclipse

How much less oil goes into the BB units? after I removed his oil line I checked the oil flow and it was down to a narrow pour(restrictor) while my MHI is a gush. His restrictor is at the turbo, I thought it was supposed to be at the filter, would that hinder anything. Anyway your thoughts are appreciated as well as your knowledge on warranties and what not to say to garrett. Can really not rebuild garrett turbos?

You cannot rebuild *ball bearing* turbos. Garrett journal bearing turbos are fully rebuildable.

Ball bearing turbos require just enough oil to lightly lubricate the bearings, unlike a journal bearing turbo which requires a decent amount of oil VOLUME (noticed I said volume, and not pressure) to keep the bronze journal bearings from contacting the housing and the shaft.

Being that ball bearing turbos require such a small amount of oil, they're often desireable because there is less of a chance of turbine seal leakage.

The oil feed should've been run to the head, with a .030" restrictor and an inline filter.

[blcknspo0ln]

Originally Posted by jusmx141

You cannot rebuild *ball bearing* turbos. Garrett journal bearing turbos are fully rebuildable.

Ball bearing turbos require just enough oil to lightly lubricate the bearings, unlike a journal bearing turbo which requires a decent amount of oil VOLUME (noticed I said volume, and not pressure) to keep the bronze journal bearings from contacting the housing and the shaft.

Being that ball bearing turbos require such a small amount of oil, they're often desireable because there is less of a chance of turbine seal leakage.

The oil feed should've been run to the head, with a .030" restrictor and an inline filter.

Justin, OT question, but I know you work/own? a shop so I'll ask away. What oil pressure are BB CHRA's truly getting from the head with a garrett restrictor? Also, what is the 'book' value Garrett wants these CHRA's to see? just curious.

[jusmx141]

Recently, I've adopted this text from Garrett for any question on Ball-Bearing turbo oil plumbing:

"Garrett ball bearing turbochargers require less oil than journal bearing turbos. Therefore an oil inlet restrictor is recommended if you have oil pressure over about 60 psig. The oil outlet should be plumbed to the oil pan above the oil level (for wet sump systems). Since the oil drain is gravity fed, it is important that the oil outlet points downward, and that the drain tube does not become horizontal or go “uphill” at any point."


I believe the specified pressure for Garrett Ball-Bearing operation is between 30-60psi, which is fully achievable from the head. Some folks say "pressure at the head can be as low as 15psi at idle!!" but at idle, the turbo has no load. As long as it's getting SOME oil, it should be fine.

On my buddy's 2G (which still has the balance shafts) we often see enough oil pressure while driving to nearly PEG the stock gauge. This would be way too much for a housing-fed ball-bearing turbo, and is even too much for some journal-bearing turbos. Too much oil pressure is bad for the seals no matter what type of turbo you're using.

[daren_p]

Originally Posted by blcknspo0ln

Justin, OT question, but I know you work/own? a shop so I'll ask away. What oil pressure are BB CHRA's truly getting from the head with a garrett restrictor? Also, what is the 'book' value Garrett wants these CHRA's to see? just curious.

I seem to recall reading on Garretts site that they recommend 40-45psi at full load. I also know Robert from FP told me they have tested their BB center sections down to 10psi, full load & had no issues/great results.

To the OP, was your buddy running an inline filter? Their recommended for BB center sections, especially if your going to break in a motor with one. If he didn't run one, that could have easily been the cause of the turbos death.