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It's Decided. 2.5 Turbo. Winter 2019

Wascally Wabbit1

Ready to race!
I guess I can run the return to the piping just before the intake as the biggest port on IE's intake is 1/4. Would I still need a breather on the can if it's a closed system just incase theres a pressure build up?

My car is Canadian and has an SRI system. I'm near positive it does at least, isnt that where the hose before the intake goes???
If it has an SAI (I think this is what you meant by SRI) there will be 2 hoses connected to the air intake. If there is only 1 then no SAI. I am pretty sure MLue said he didn't have one so I thought the SAI is just a US emissions thing. If you only have 1 hose at the air intake tube it goes to the oil filter breather. This lets air into the crankcase. PCV let's air out. The circle of life.
 

OrangeSpy

Ready to race!
If it has an SAI (I think this is what you meant by SRI) there will be 2 hoses connected to the air intake. If there is only 1 then no SAI. I am pretty sure MLue said he didn't have one so I thought the SAI is just a US emissions thing. If you only have 1 hose at the air intake tube it goes to the oil filter breather. This lets air into the crankcase. PCV let's air out. The circle of life.
Ohhh, yes there is only one. And yes I did mean SAI.

Perfect! That makes things a little easier.
 

FlowMK6

Ready to race!
Canadian cars don't have them. Only us tree huggers to the south.
Depends of year and location. SAI is used to heat up the catalytic converter and the wideband quicker, this way the car will go on closed loop quickly and the catalytic converter will be more efficient. CBUA engine all have the SAI

Hold on now, just to be clear the catch can attaches to the breather hose then either to atmosphere or the intake?

I think I just misread your post haha
Since I'm venting to atmosphere, both my breather and PCV hose vent to the catch can. The catch can itself is at atmospheric pressure (14.7psi) anything over 14.7psi in the PCV system will vent to the catch can. In my case the breather hose that goes to the engine doesn't really supply air as the OEM PCV system

I know the PCV system can be confusing and I feel I should give some explanations, you might already know what I'm about to say, but maybe it will enlight you

When piston ring wear, with cylinder pressure some blow-by gases will go through the pistons ring right into the crankcase. When there is a lot of blow-by gases in the crankcase, the gases have no where to go and it will start building up pressure, which is not good. The solution manufacturers use is the PCV system. With our engine, we have a PCV diaphragm that close under high vacuum and is fully open when the intake manifold reach atmospheric pressure

When the engine is idling, there is almost no blow-by so no need for ventilation. Under acceleration (load), the intake manifold is at atmospheric pressure since the throttle is fully open, there is more cylinder pressure, so more blow-by and the need for ventilation, this is why the PCV diaphragm is fully open when the intake manifold reach atmospheric pressure to let the pressure evacuate in the intake manifold (if you want to get explanations about the PCV diaphragm, feel free to ask)

Then there is a breather than brings atmospheric pressure from the intake piping into the crankcase, it brings fresh air but also make sure that the crankcase isn't under vacuum

The PCV system of our engine is good for NA application but with forced induction, if you vent into the intake manifold, you will be putting boost into your catch can, the PCV system, you will wear the PCV diaphragm faster too. If you want to vent to the engine, you will have to vent into the intake piping before the turbo inlet. In that case, you are running venting to the engine but at atmospheric pressure, yeah the turbo do some suction and will be a little bit more efficient that a setup that vent to atmosphere using the same hose diameter, but a catch can isn't 100% efficient and some blow-by will go through your turbo and then right into the engine

That's why I'm venting to atmosphere because it's cleaner for the engine. With that kind of setup, the diameter size is more important than a setup that use a little vacuum to help with ventilation. The higher the pressure differential is, the bigger the flow / velocity / ventilation is. Since venting to atmosphere will have less pressure differential than a setup that use a little vacuum, it's important to use big hose. When the crankcase will build up pressure and vent to the catch can, due to the bigger volume of the hose (big diameter hose), it will cause a pressure drop, since the blow-by have to fill a bigger volume. Same thing with big intercooler piping, it takes more time to reach a certain boost level because you have to flow more air to fill and reach the same pressure. In our case, the blow-by fill a bigger volume, so the pressure drop and you now have an efficient ventilation

So a setup that vent to atmosphere with big hose diameter is as much efficient than a setup that vent to the engine and use a little vacuum. Having too much vacuum, will suck up more oil vapor and blow-by

If you plan to vent to atmosphere use a good catch can that have a breather filter on top, 2 ports and a good filter inside (oil - air separator) but not to restrictive to allows a good ventilation and to prevent having oil in the breather filter. Honestly, my engine bay stay clean and the filter doesn't get that much oily. Having two port allows more ventilation, if my PCV hose (the one on the valve cover) pressurize due to high crankcase pressure, it will vent through the breather hose (the one on the engine)

I hope this infos helps you, sorry if I'm unclear, English isn't my main language, I'm doing my best
 
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OrangeSpy

Ready to race!
Depends of year and location. SAI is used to heat up the catalytic converter and the wideband quicker, this way the car will go on closed loop quickly and the catalytic converter will be more efficient. CBUA engine all have the SAI



Since I'm venting to atmosphere, both my breather and PCV hose vent to the catch can. The catch can itself is at atmospheric pressure (14.7psi) anything over 14.7psi in the PCV system will vent to the catch can. In my case the breather hose that goes to the engine doesn't really supply air as the OEM PCV system

I know the PCV system can be confusing and I feel I should give some explanations, you might already know what I'm about to say, but maybe it will enlight you

When piston ring wear, with cylinder pressure some blow-by gases will go through the pistons ring right into the crankcase. When there is a lot of blow-by gases in the crankcase, the gases have no where to go and it will start building up pressure, which is not good. The solution manufacturers use is the PCV system. With our engine, we have a PCV diaphragm that close under high vacuum and is fully open when the intake manifold reach atmospheric pressure

When the engine is idling, there is almost no blow-by so no need for ventilation. Under acceleration (load), the intake manifold is at atmospheric pressure since the throttle is fully open, there is more cylinder pressure, so more blow-by and the need for ventilation, this is why the PCV diaphragm is fully open when the intake manifold reach atmospheric pressure to let the pressure evacuate in the intake manifold (if you want to get explanations about the PCV diaphragm, feel free to ask)

Then there is a breather than brings atmospheric pressure from the intake piping into the crankcase, it brings fresh air but also make sure that the crankcase isn't under vacuum

The PCV system of our engine is good for NA application but with forced induction, if you vent into the intake manifold, you will be putting boost into your catch can, the PCV system, you will wear the PCV diaphragm faster too. If you want to vent to the engine, you will have to vent into the intake piping before the turbo inlet. In that case, you are running venting to the engine but at atmospheric pressure, yeah the turbo do some suction and will be a little bit more efficient that a setup that vent to atmosphere using the same hose diameter, but a catch can isn't 100% efficient and some blow-by will go through your turbo and then right into the engine

That's why I'm venting to atmosphere because it's cleaner for the engine. With that kind of setup, the diameter size is more important than a setup that use a little vacuum to help with ventilation. The higher the pressure differential is, the bigger the flow / velocity / ventilation is. Since venting to atmosphere will have less pressure differential than a setup that use a little vacuum, it's important to use big hose. When the crankcase will build up pressure and vent to the catch can, due to the bigger volume of the hose (big diameter hose), it will cause a pressure drop, since the blow-by have to fill a bigger volume. Same thing with big intercooler piping, it takes more time to reach a certain boost level because you have to flow more air to fill and reach the same pressure. In our case, the blow-by fill a bigger volume, so the pressure drop and you now have an efficient ventilation

So a setup that vent to atmosphere with big hose diameter is as much efficient than a setup that vent to the engine and use a little vacuum. Having too much vacuum, will suck up more oil vapor and blow-by

If you plan to vent to atmosphere use a good catch can that have a breather filter on top, 2 ports and a good filter inside (oil - air separator) but not to restrictive to allows a good ventilation and to prevent having oil in the breather filter. Honestly, my engine bay stay clean and the filter doesn't get that much oily. Having two port allows more ventilation, if my PCV hose (the one on the valve cover) pressurize due to high crankcase pressure, it will vent through the breather hose (the one on the engine)

I hope this infos helps you, sorry if I'm unclear, English isn't my main language, I'm doing my best
That's great! thanks for the detail.
So it seems like I have a couple options.

If breathing to atmosphere I could run a system like yours where the PVC runs to the inlet and breather to outlet
or;
Put a filter on the breather then run a single hose from the pcv to the catch can.
And for a returned system
Again put a filter on the breather then connect the pvc to the catch can and return it to the pre-turbo side of the intake for a bit of vaccum. If running it to the post turbo side of the intake use a check valve

yes??
 

FlowMK6

Ready to race!
That's great! thanks for the detail.
So it seems like I have a couple options.

If breathing to atmosphere I could run a system like yours where the PVC runs to the inlet and breather to outlet
or;
Put a filter on the breather then run a single hose from the pcv to the catch can.
And for a returned system
Again put a filter on the breather then connect the pvc to the catch can and return it to the pre-turbo side of the intake for a bit of vaccum. If running it to the post turbo side of the intake use a check valve

yes??
If venting to atmosphere, I would take a catch can with an filter breather on top and 2 inlets. So both the PCV hose and breather hose vent to the catch can

As for your setup option of putting a filter on the breather filter and the PCV hose to the catch can, your will need a filter on the catch can too, so I would put the breather and PCV pose to the catch can since the catch can is already at atmospheric pressure

If your want to recirculate, your way by routing it to the pre-turbo side is good

But post turbo, a check valve is mostly a one way valve that allow the flow in one direction (isolate vacuum from boost), by using a check valve the boost won't go in the PCV valve, but only the vacuum and under vacuum the PCV is either fully close or partially open. You would need a check valve that open with just a little vacuum so you would be close to the atmospheric pressure

Honestly, I would just route pre-turbo if I wanted to recirculate and if I want to vent to atmosphere, both the breather and PCV hose to the catch can
 

OrangeSpy

Ready to race!
If venting to atmosphere, I would take a catch can with an filter breather on top and 2 inlets. So both the PCV hose and breather hose vent to the catch can

As for your setup option of putting a filter on the breather filter and the PCV hose to the catch can, your will need a filter on the catch can too, so I would put the breather and PCV pose to the catch can since the catch can is already at atmospheric pressure

If your want to recirculate, your way by routing it to the pre-turbo side is good

But post turbo, a check valve is mostly a one way valve that allow the flow in one direction (isolate vacuum from boost), by using a check valve the boost won't go in the PCV valve, but only the vacuum and under vacuum the PCV is either fully close or partially open. You would need a check valve that open with just a little vacuum so you would be close to the atmospheric pressure

Honestly, I would just route pre-turbo if I wanted to recirculate and if I want to vent to atmosphere, both the breather and PCV hose to the catch can
Perfect I think I'll run a set up like yours. I just need to modify my cat can now..., thanks again!
I really thought this was a simple task I didnt realize how much there was to it. You've saved my engine for the 100th time haha
 

VWLife

New member
Hey OrangeSpy, I hope you're taking good notes as you go!
If the price isn't too silly, I'm hoping I can do the same with my 2013. :)
 

OrangeSpy

Ready to race!
Hey OrangeSpy, I hope you're taking good notes as you go!
If the price isn't too silly, I'm hoping I can do the same with my 2013. :)
I'm going to make a post on this site when it's all done! lots and lots of pictures. I also plan on making a tutorial video. As of right now I'm under $5000 USD. which seems big but from what I was told when I started this I wouldn't be able to do it under 10,000
 

MLue1

Go Kart Champion
I'm going to make a post on this site when it's all done! lots and lots of pictures. I also plan on making a tutorial video. As of right now I'm under $5000 USD. which seems big but from what I was told when I started this I wouldn't be able to do it under 10,000
If that's $5000 CAD, thats simple awesome!
 

OrangeSpy

Ready to race!
If that's $5000 CAD, thats simple awesome!
I'm a few hundred over 5000 CAD now :/ I could have taken some short cuts to keep it down but worries I may damage the car.
 

OrangeSpy

Ready to race!
Fuel pump question for yas.
I was told to relay the inline pump off of the fuse. I got a piggy back fuse and rigged up a relay but got to thinking... Its a returnless system, so the aftermarket pump needs to turn on and off on demand (hence relaying it off the stock pump) but I dont think that happens at the fuse... I tried finding a fuel pump relay but was only finding it for MK5s. Anyone have ideas?
 

FlowMK6

Ready to race!
Fuel pump question for yas.
I was told to relay the inline pump off of the fuse. I got a piggy back fuse and rigged up a relay but got to thinking... Its a returnless system, so the aftermarket pump needs to turn on and off on demand (hence relaying it off the stock pump) but I dont think that happens at the fuse... I tried finding a fuel pump relay but was only finding it for MK5s. Anyone have ideas?
Honestly I'm unsure our fuel pump use duty cycle. I noticed 2.0T have a fuel pump regulator module that sit right over the fuel pump. On our 2.5, we don't have have this module. I looked at the wiring diagram and power goes directly from the relay to the pump. I don't think the ecu would pulse the relay, otherwise they would have done that with the GTI too

The fuse is before the relay, I also had to put a bigger fuse, the new pump used more amperage and burned the fuse on the road, I always have fuses with me, so it wasn't too bad, but it took a while to figure out why the car stalled

Also the duty cycle is for the pump longevity not for the fuel pressure regulation, the filter is the fuel pressure regulator. I'm not sure if you mixed it up since you mentioned the return-less fuel system
 

OrangeSpy

Ready to race!
Honestly I'm unsure our fuel pump use duty cycle. I noticed 2.0T have a fuel pump regulator module that sit right over the fuel pump. On our 2.5, we don't have have this module. I looked at the wiring diagram and power goes directly from the relay to the pump. I don't think the ecu would pulse the relay, otherwise they would have done that with the GTI too

The fuse is before the relay, I also had to put a bigger fuse, the new pump used more amperage and burned the fuse on the road, I always have fuses with me, so it wasn't too bad, but it took a while to figure out why the car stalled

Also the duty cycle is for the pump longevity not for the fuel pressure regulation, the filter is the fuel pressure regulator. I'm not sure if you mixed it up since you mentioned the return-less fuel system
Ohh okay, I think I miss understood how the returnless system worked. I thought the ECU controlled the speed of the pump to deliver more or less fuel when needed.
What would you suggest when wiring an inline pump. Control the relay switch from the fuse panel or directly off the wiring for the stock pump?
Right now I have the relay switch piggybacked onto the fuel fuse but am leaning toward splicing the fuel pump wiring instead.
 

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FlowMK6

Ready to race!
Ohh okay, I think I miss understood how the returnless system worked. I thought the ECU controlled the speed of the pump to deliver more or less fuel when needed.
What would you suggest when wiring an inline pump. Control the relay switch from the fuse panel or directly off the wiring for the stock pump?
Right now I have the relay switch piggybacked onto the fuel fuse but am leaning toward splicing the fuel pump wiring instead.
On the return-less system, the fuel pump flow fuel through the filter and the filter have a restriction that build up fuel pressure. Excessive pressure return to the fuel tank and the pressurized fuel goes to the fuel rail

On performance oriented engine such as the GTI, they have a module that pulse the pump on and off depending of the needs to make the pump last longer

For the wiring, I wouldn't splice the fuel pump harness, I'm unsure if it would support the amperage for 2 pumps. From what I understand you have a second relay but exclusively for your inline pump ? If that's the case, I would use your piggyback to trigger the inline pump relay and run a new wiring from fuse panel to the inline pump. That would isolate both pump circuit

Then for the pump setup, the in-tank pump should flow to the inline pump and the inline pump to the filter
 

OrangeSpy

Ready to race!
On the return-less system, the fuel pump flow fuel through the filter and the filter have a restriction that build up fuel pressure. Excessive pressure return to the fuel tank and the pressurized fuel goes to the fuel rail

On performance oriented engine such as the GTI, they have a module that pulse the pump on and off depending of the needs to make the pump last longer

For the wiring, I wouldn't splice the fuel pump harness, I'm unsure if it would support the amperage for 2 pumps. From what I understand you have a second relay but exclusively for your inline pump ? If that's the case, I would use your piggyback to trigger the inline pump relay and run a new wiring from fuse panel to the inline pump. That would isolate both pump circuit

Then for the pump setup, the in-tank pump should flow to the inline pump and the inline pump to the filter
Alright great! I already have that set up and wasnt looking forward to undoing it all.

It wouldnt need to support 2 pumps amperage however if I did it the other way. It would only turn the relay on. The main power supply is coming straight from the battery.
 
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