Well the belt pump will always pump air. It is a remote valve the switches the air flow, so no mod needed to the pump.
PCV system/ explanation and mod
- Thread starter jimi87-t
- Start date
Perhaps someone can explain. Is there any fresh air inlet into the crankcase? How can we expect to suck out crankcase gases if there is no fresh air coming in to vent it?
Also, I know that many other engines use PCV valves to put a fair amount of vacuum on the crankcase to help seal piston rings. With the 7M system, it looks like most of the vac pulls on atmosphere at the intake, result in a very very weak vac on the crankcase. What gives?
Also, I know that many other engines use PCV valves to put a fair amount of vacuum on the crankcase to help seal piston rings. With the 7M system, it looks like most of the vac pulls on atmosphere at the intake, result in a very very weak vac on the crankcase. What gives?
MA70witBoost
Registered Drifter
Hey Ian, Is there really enough vacuum under idle to pull oil vapors into the intake manifold at idle? Id think that the only real problem would be under boost, having the oil vapors flow back through the turbo.
Im running a stock PCV setup but have a catch can placed between the pcv outlets on the valve covers and the turbo inlet.
Im running a stock PCV setup but have a catch can placed between the pcv outlets on the valve covers and the turbo inlet.
MA70witBoost;1322391 said:
You get the most vac on decel, followed by idle. There is nothing wrong with the stock setup, if you have provisions for it. I would put the catch can between the valve covers and intake manifold, how much time does your car run under positive manifold pressure vs not? Think about it.
At idle it's using the port on the TB so yes there's more than enough to cope with the minimal blowby present 
In reference to post #24. Why would we need the pump in this position at all? The air pre-turbo is always in a vacuum situation (i.e the air in the accordian pipe or WHY) It just experiences a larger vacuum when the turbo spools. Can't it go, valve cover>catchcan>accordian pipe? I understand the benefit of strong crankcase vacuum, but i don't understand why regular engine vacuum isn't enough?
Is there a port on that aftermarket throttle body for vacuum already or is that something that you did? I am using the Q 45 TB, and I can't recall if I have a vacuum port on it (mainly because my car has been down for so long...) I would also be interested to see the response to the question right above me^^^^
I drilled and tapped my FFIM just behind the TB then used a Ford PCV valve plumbed to the Catch Can, this way I had good suction at idle and it would close under boost rerouting the vapours to the Turbo Inlet under boost.
"Most" preformance ring sets are thin and prone to flutter pulling a vacuum in the crankcase helps stabilise them promoting better seal with less blowby.
"Most" preformance ring sets are thin and prone to flutter pulling a vacuum in the crankcase helps stabilise them promoting better seal with less blowby.
manzai;1322502 said:
No, it isn't. There's very little pressure drop across the air filter and AFM. Nor do you want any. Think about it...
black87turbo;1322532 said:
There is a VAC port on that TB but you can't see it in that pic, but it is pre-throttle plate so it is being used for EGR VAC.
The -AN fittings and pipe you see on top of the TB is the EGR plumbing
And I had to drill and tap for that.EGR, another good thing to have for a happy engine
IJ.;1322551 said:
I did a similar setup, valvecovers to a "T" one end directly to the TB, other end goes to a check valve then to turbo inlet, I liked the idea of having a vacum on the crank(Not sure if it can be fully acheived with the stock setup). And when I hit positive mani pressure, the check valve opens letting fumes into the turbo inlet.
I don't have a catch can because my car doesn't see many k's, and a well running engine shouldn't technically need one.IMO. Once my car is a DD, I will deffinetly consider one.
manzai: You don't want a pressure differential from the air filter to the turbo, why do you think people use those K&N and high flow filters. A very dirty filter will give you one.
What about this?
Or does it have to be before the TB? If so, at idle since the TB is closed, the air just goes back through the intercooler to the turbo compressor inlet?
BTW- I'm running an FFIM with Q45 TB, idk if there is a port I can plug into on it.
Or does it have to be before the TB? If so, at idle since the TB is closed, the air just goes back through the intercooler to the turbo compressor inlet?
BTW- I'm running an FFIM with Q45 TB, idk if there is a port I can plug into on it.
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The "main" vacum needs to be behind the TB valve(intake manifold), or else you don't have much pressure differential.
7Mboost: Not really, the majority of fumes travel from the crank(valve covers) to the TB.Period. The point of the CC is to intercept this. I think as the turbo inlet as an auxilary dump used ONLY when the turbo is boosting. Techincally speaking the 7M-GE PCV setup is better, but turbocharged engines...its the nature of the beast.
I'm not sure what IJ's setup is, but I would do the same if there isn't a port after the TB butterfly valve.
7Mboost: Not really, the majority of fumes travel from the crank(valve covers) to the TB.Period. The point of the CC is to intercept this. I think as the turbo inlet as an auxilary dump used ONLY when the turbo is boosting. Techincally speaking the 7M-GE PCV setup is better, but turbocharged engines...its the nature of the beast.
I'm not sure what IJ's setup is, but I would do the same if there isn't a port after the TB butterfly valve.
7Mboost;1322586 said:
The orifice on the TB is after the throttle plate, meaning that when the throttle plate is closed, it is pulling manifold VAC. Air will not reverse flow in the IC, unless something is totally F'd up.
You can put the catch between whatever you are trying to keep clean.
jimi87-t;1322606 said:
So I should do this order: cam covers > catch can > intake manifold. Can I just add another port to the catch can and run that to the intake, or would I need another catch can?
