Different question.

You gave me some advice some time back for my rear mount turbo. Just looking at some forums tonight and have been searching for hours on pcv topics, more specifically my engine has one pcv on one valve cover then just a vacuum line to the other cover, both in stock configuration run to intake, I'm assuming for vacuum. I've read some thoughts on circulation? But my question is, would it be wise to run both lines to a catch can and should that can be a closed system from intake side to pull vacuum to help crankcase pressure or just a vented system? Thanks again in advance

 

This has been discussed a bunch, lots of different opinions on it https://www.theturboforums.com/search/394550/?q=pcv&o=relevance&c[node]=214

All in all, you need to have some form of crankcase ventilation, even when under boost. When your turbos pressurize the intake those PCV lines are either blocked or forcing pressure into the crank. So you need to do one or more of the following:

Atmospheric breathers
Pull your PCV vacuum from the intake side of the turbo
Run a vacuum pump
Run a crankcase evac system

Each has pros/cons. I think most guys are just venting to atmosphere, I think the ultimate solution is a belt driven vac pump, but there is cost and space involved.

 

Thanks once again for the information. I suppose I should stop searching the Toyota forums, turbo applications for the 5vz are just not common, I didn't even think to search the forum dedicated to turbo applications.... I really like the crankcase evap set up. I had a basic thought of that kind of system, but mine was certainly over complicated with vacuum blocks and lines running everywhere.. I'll dig into that link you sent and learn what I can. Thanks

 

I dove down a bit of a hole after you posted this response. I understand no matter how I look at it the belt driven evac is the best option. Now with only running 300 hp max and 220k miles on the old toyota 6 cylinder (not that the 5vz fe would have a problem going over 300k) would it be wise to just wait until I do an engine swap? The swap will be a no expense spared deal, so do it right. I honestly, as bad as it seems, can't wait till the motor goes and I can start fresh. I read that the pump evac has some longevity issues across the board, but without it you lose crank ventilation as soon as you lift out of the throttle. Just the debate of run something that only "works" for the old motor (just a closed vented system) and run the right set up when I swap in the new motor. Just looking for opinions I suppose.

 

Run either exhaust based evac ( https://www.summitracing.com/parts/...zU_QfoiwtyY2R9bshkO_EUvZJeNCGaVgaAmH8EALw_wcB ) or route your PCV to the front of the turbo, it will be fine.

 

Awesome thanks. I was curious if I needed to go all out on a low hp tired motor. I'm assuming that I would need to run the exhaust evac after any o2 sensors to avoid any fouling or will it burn it off fairly efficiently? Or could a guy run through a catch can before the vacuum source on the exhaust and not have to worry about sensors? Any effect of afr reading if I leave one valve cover to pull fresh air or just run both valve cover lines to catch can then to vacuum source in exhaust. Or am I just over complicating it all.

 

Just make sure it's after the O2. I put the O2 as close to the turbo as I can get and the Evac down by the trans, generally.

 

Sounds good. My turbo is currently at my rear axel and o2 is the recommended 24" after, so I'll try some good line for that run and keep in mind that I have to go post sensors. Thanks for the input, it is extremely helpful.

 

I think the evac system has to be post turbo, its venturi and I am not sure how that works. PCV at the turbo inlet will work fine.

 

Ya know, the rear mount turbo sure was cheaper to do in my own shop. But an under the hood mount it just far more simple for making things work together, I'm going to move it under the hood this winter. Great learning experience right, I get to do it twice! I'm sure I have most all that I'll need anyhow to move it at this point. In the meantime, I'll take advice for y'all and get some kind of crankcase evac going to keep the motor happy. Thanks a ton again and any advice yall have is more than welcome. I may start a new thread on the process of moving it up front and how I do it, so if you see it please feel free to let me know what you think. 2 years of forcing this thing to work has just shown a rear mount application is not the best for my rig.