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curious if its worth going to a moroso style evac on my turbo car? would welding both fittings into the DP and running the breather tubes to them do any good? i know this is a bigger thing for non turbo guys. Any input on this would be great or worse case ill stick with breathers with tubes going into a catch can. thanks guys
 

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I know brian from BG does this and it works awesome. He only uses one. for a single downpipe
 

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We use them and have gotten up to 20" of vacuum.
 

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Discussion Starter #4
now where did you guys stick the valve in at? in the DP? after the muffler? curious about trying this out and running both breathers right into the exhaust in the valve and see how it helps out. thanks guys
 

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We use them and have gotten up to 20" of vacuum.
You're getting that much vacuum on a turbo engine?

In my experience, naturally aspirated engines were able to pull quite a bit more vacuum from the exhaust that a turbo engine. I don't quite get even a full inch of vacuum from my downpipe, so I've opted to use the intake pipe (pre-compressor) as a vacuum source.
 

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We have had good luck with V-8 and single turbo making about 1100 hp and feeding both valve covers into a single 4.5" down pipe. We never had this much vacuum in n/a app either. Consider 540 cid +/- 1000 hp n/a with dual 4" vs 1100 hp thru the single 4.5"
 

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Are you running it direct to the exhaust, or using some kind of catch tank?

Im interested in doing something similar, but I dont want to end up with a smokey ass exhaust!
 

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I like to use a catch can and then go to the exhaust.
 

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No form of breather or return from the catch can aside from to the exhaust I take it; the weight of any actual liquid just makes it sit in the bottom of the catch can?

Simply- Valve covers-> Catch can-> Exhaust?
 

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are you guys using one side of the valve covers or both?
 

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Anyone have pics of there setup? If you have a baffle in your valve cover do you still need to go to a catch can? Is the catch can sealed or does it have a breather.
 

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If you use a vented can ( breather) it would allow the vacuum to escape
 

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im curious about this myself. i think one thing to consider is whether or not a muffler is being used which could increase the backpressure in the exhaust
 

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So if right now I'm running a 10an line from my valve cover to a vented catch can. Do I leave this system setup and add a closed system or have the closed system as my only form of venting. Just worried I old pull more air out then what could get in.



If you use a vented can ( breather) it would allow the vacuum to escape
 

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So if right now I'm running a 10an line from my valve cover to a vented catch can. Do I leave this system setup and add a closed system or have the closed system as my only form of venting. Just worried I old pull more air out then what could get in.
If I were you, I'd remove that system and add a closed system instead. But I'd be hesitant about using the exhaust as your vacuum source. Test it first to see how much pull it has. Most DSMers aren't able to sucessfully use the exhaust system to evacuate the crankcase. But the intake pipe (pre-compressor) should work just fine.

Consider something like this:

 

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the thing is this.. Oil getting to the turbo and to the impeller
 

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Thanks for the info. What is the reason on a DSM it wouldn't work off the DP? Also in the system you showed do you still need a check valve?
 

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Thanks for the info. What is the reason on a DSM it wouldn't work off the DP? Also in the system you showed do you still need a check valve?
No need because the turbo will be under vacuum when you get in on the thorttle, thats when you need it. while you are cruising you dont need vacuum.
 

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im curious about this myself. i think one thing to consider is whether or not a muffler is being used which could increase the backpressure in the exhaust

I had Flowbastards on my Procharger setup when I first started running it . Talk about backpressure ! Going down the highway pushing 15psi on the boost gauge . Blew out both check valves on my Moroso evac system , pressurized the crankcase , blew oil out all over the motor , headers , and everywhere else ! Thought I blew the motor ! Almost burned it to the ground .
 

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the thing is this.. Oil getting to the turbo and to the impeller
The purpose of the catch can is to catch and store the oil in the air. A good catch can will be baffled or filtered to not allow any contaminants in the air past the can itself.

Thanks for the info. What is the reason on a DSM it wouldn't work off the DP? Also in the system you showed do you still need a check valve?
Many guys have measured vacuum in the downpipe on a DSM and haven't been able to reach a full inch of vacuum. It seems that most of us are running pretty large exhausts that create a slow speed exhaust. This slow speed doesn't allow the pressure to drop low enough to be beneficial for crankcase evacuation. But like I said, it might be worth measuring yourself as every car is slightly different. I can tell you that I have yet to find a 4G engine that has been able to successfully pull it off though, and I've looked around quite a bit.

You could bottleneck your exhaust to speed up the flow and that would create a venturi that might allow a great enough pressure differential to evacuate the crankcase - but at that point, you're creating a potential exhaust restriction, so I really wouldn't say it would be worthwhile trade-off.

No check valve required in the set-up pictured above. Mine is exactly the same as the one pictured except that I'll be running a single -12 from the catch can to the intake pipe, as apposed to dual -10's.
 
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