Hey all. I've been working with ATP turbo on a bit of an issue I've been having but am a little torn on his suggestion.

Turbo is a brand new Garrette TB2522 from an old Sunfire professionally tuned on E85 @ ~14 Peak PSI. PCV is from the turbo 323.


Currently my car has a -4AN hose going to a 1/2-20 in. AN to Inverted Flare Fitting (Aeroquip FBM2182 - Aeroquip High Pressure Adapters - Overview - SummitRacing.com) and I have noticed smoke during start up and oil leaking from the CHRA. My thoughts were the oil feed was too large at a -4 AN and I should add a restrictor.

ATP Said the following:
Before you add a restrictor, you have to know how much oil pressure the motor is putting out (how much is going into the turbo). Do you have an oi pressure gauge on the car?

It may be at the right pressure now. If that is the case and something is leaking, then something is out of place on the setup that is forcing the leak or your turbo just leaks. In this case, adding a restrictor is just a bandaid and might cause the turbo to fail from oil starvation.

My Response:
The oil pressure varies from 30 to 60 PSI when warm and accelerating. This is a manual pressure gauge. The turbo was brand new (never used/installed/etc.) and when I had it clocked, the tech said everything looked great. Turbo has about ~10 to ~15 track days on it. Car was professionally tunned.

Them:
Those are perfect oil pressures for the turbo so do not add a restrictor

Me:
The oil drain is -10 fitting and has no obstructions or bends so I dont think its that. The crack case vents to atmosphere via a breather on one side and through a check-valve (PCV) on the other that goes to a makeshift catch can (that is always dry).

Them:
Your oil drain line is unobstructed, but it's possible that the crankcase itself cannot vent enough out of your existing breathers. When that happens, the crankcase pressure stays trapped in your crankcase and it will begin to build pressure. Since your oil drain drains into your crankcase, the pressure within the crankcase will push itself up the drain hose into your turbo and act like an obstructed oil drain. When this occurs, the oil has no choice but to leak into the housings.

Me:
Any recommendations? Seems like in the Miata community most people are running -3 fittings because of the oil pressure issue. With the crankcase pressure issue, wouldn't my catch can show signs of oil because it is COMPLETELY dry same with the breather.

Them:
It's possible to have inadequate breathers and NOT push oil into the catchcan.

You:
...............................

I can really use your suggestions.

 

I'm having similar issues with my churbo. I Still haven't gotten to the bottom of it either.

Is yours leaking out of the intake side or turbine? Is your catch can routed to intake manifold vacuum?

 

I'll have to take a look, maybe clean it off with some brake clean and sleep under the car while its running.

Catch can is not routed to intake manifold.

 

Wait, it's an external leak?

 

I don't understand why people don't run restrictors on every turbo and every setup. The new BorgWarner EFRs have them BUILT IN.

Ignore ATP, put a restrictor in the damn turbo.

 

OK boys and girls, here is the pic

 

can a mod move this to a more appropriate section please.