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Reducing oil pressure to stop blue smoke on deceleration

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94 rx7

So I've spent a bunch of time trying to sort this out and wondering what else I could do. I have a fully rebuilt streetport motor, exotic large turbo (where my issue lies I believe) and deleted OMP so full premix. The motor runs like a dream and there is zero smoke at idle. I do get some on cold start which I know is pretty normal and then it fully clears up. I have put a go pro on the back of the car and I spit out a puff of blue every single time I let off the gas at any rpm (so during shifts or just deceleration). Now I do have the oil filler neck run to an oil catch can and then routed pre compressor housing so I am sure it shouldn't be too much crank case pressure. I have pulled the plugs and there is zero oil inside the motor itself. Now I know I have an upgraded oil pump so I range 130-150psi oil pressure that will drop down to 80 at idle. I am running -3 to the turbosmart oil regulator which has been able to bring the pressure down to 50psi and has led to the car being drivable and not whiting out my neighborhood, but I have a feeling this is still too much for this turbo. By exotic turbo I mean its off a 2005 champ car and is a triple ballbearing setup that IHI made for the race teams only. I think I need to drop the oil pressure even lower but cannot find anything other then the turbosmart piece. I have also tried the smallest reducer inline but that doesn't help at all, actually makes it worse. I'm hoping someone has an idea as I'm spent trying to sort this issue out. For a last bit of info I have a -10 drain off the turbo so I don't think its an issue with the turbo draining.

The only other thing I can think of that I may try today is adding a second PCV to the system. Add a second line to the oil filler, a one way check valve and put it in the UIM. Possibly giving me vacuum in the crank case off throttle (just in case it still has to do with pressure in the system)

Is there a reason you don't fix the turbo (have it serviced/rebuilt), since it sounds like that is where the oil is entering the exhaust? I'm sure the design mileage on a race part like that is measured in 10's of hours of service.

Why isn't the Turbosmart holding the pressure at 40 psi -- perhaps that's why they spec -4 instead of -3 lines.

https://www.turbosmart.com/product/opr-t40-40psi-black/

Have you contacted IHI to ask for their recommendations / help?

Turbo has freshly been done with my turbo engineer. I thought it was the turbo the first time we had major oil problems and he has confirmed the turbo has no issues. I know the turbosmart is meant to only do 40 and yes it could be the -3 but I am also putting it at its limit of 160psi so I assumed it was just the overpressure of the system on it. Would a -4 change it that much?

As for asking IHI they wont give any info out on this turbo