Catch Can Plumbing Different For Map Vs Maf (Photos Inc)

[HIRISK]

Hi Guys,

I currently have the PCV blocked off and the catch can vented to atmo.

But I want to plumb the catch can back to the intake system, but am concerned this 'may' be a problem as I have not got the PCV plumbed.

Is it true that as I am running MAP system (PFC D-Jetro) I can run the PCV blocked off and use the intake suction alone to draw fumes through a baffled catch can and into the turbo intake stream?

Thoughts?

Feedback?

Thanks in advance.

[The Dan]

I currently have the PCV blocked off

This is a problem.

Why is it blocked off? You are better off with it connected.

[HIRISK]

This is a problem.

Why is it blocked off? You are better off with it connected.

The set up on the car is as I bought it, so I am just trying to go over it all and refine where needed.

I am making an assumption the PCV is blocked off as I can't see any pipe work going back to the cam cover?

Where exactly is the PCV?

[The Dan]

It's usually screwed into the manifold where your arrow is pointing. The PCV gives you a better headstart to get your crankcase into negative pressure rather than starting from 0. The air going through the turbo drawing air from the cam covers is there from factory also. Both are very important.

The second picture is spot on but it's difficult to get the PCV plumbed back in because you now only have the 90deg fitting there.

If it were mine, I would now run the PCV to the catch can somewhere. It will have the same effect in the end

[Moodles2]

I've never seen the PCV blocked on a RB26 until now.

[R.3.2.G.T.R]

I've never seen the PCV blocked on a RB26 until now.

mine is blocked off as per ARC catchcan kit instructions, same setup as OP except i have a single hose coming into the catchcan

http://i124.photobucket.com/albums/p38/60ragtop/Picture110.jpg

[SiR_RB]

Mine was setup exactly like the first pic, all i did to it was hook up the PCV valve (required some new lines/fittings)

Works perfectly

[HIRISK]

I've never seen the PCV blocked on a RB26 until now.

Really? I have seen a lot of catch can set ups where the PCV is blocked, but a lot of them vent to atmosphere.

I am trying to get my head around whether it will be an issue for me to no longer vent to atmosphere and connect to the rear turbo intake instead.

It's usually screwed into the manifold where your arrow is pointing. The PCV gives you a better headstart to get your crankcase into negative pressure rather than starting from 0. The air going through the turbo drawing air from the cam covers is there from factory also. Both are very important.

The second picture is spot on but it's difficult to get the PCV plumbed back in because you now only have the 90deg fitting there.

If it were mine, I would now run the PCV to the catch can somewhere. It will have the same effect in the end

Found it - thanks.

If you look at the picture below you will see a blue anodised metal grub screw in the hole it was once connected to.

Mine was setup exactly like the first pic, all i did to it was hook up the PCV valve (required some new lines/fittings)

Works perfectly

If you had a set up the same as my current one (first pic) where did you plumb the PCV in??

[SiR_RB]

I had to get a fitting welded onto the rear breather outlet pipe, thus reusing the stock PCV factory hose, and then 2 lines to catch can

[HIRISK]

I had to get a fitting welded onto the rear breather outlet pipe, thus reusing the stock PCV factory hose, and then 2 lines to catch can

Great,

I think this is what I will do also.

But I wonder if I need to run an equaliser tube between the two cam covers?

So this is how I will set it up (tba on the equaliser)...

[HIRISK]

Interesting to see the Racepace set up blocks the PCV, I will need to have a chat with them, as I am sure they know what they are doing.

So maybe it is not so much of an issue?

[Hanaldo]

Great,

I think this is what I will do also.

But I wonder if I need to run an equaliser tube between the two cam covers?

So this is how I will set it up (tba on the equaliser)...

Wait what? What you are suggesting here is exactly the same as you have it now, all you're doing is adding unnecessary lines. The PCV is part of the cam cover, if you're connecting it to the breather on the cam cover then all you are doing is making a loop that does nothing.

[HIRISK]

Wait what? What you are suggesting here is exactly the same as you have it now, all you're doing is adding unnecessary lines. The PCV is part of the cam cover, if you're connecting it to the breather on the cam cover then all you are doing is making a loop that does nothing.

No, there are two changes to what I have now.

1) No more vent to artmosphere - the air filter on the can is replaced by a line running to the rear turbo intake

- This will eliminate odurs / smell I currently get from venting atmo

- This is legal as currently vent to atmo is not in Victoria

2) The PCV is re-installed where it currently is blocked off with a grub screw and has the factory line re-fitted that goes from the PCV to the cam cover

(which is where I need a custom fitting that has TWO outlets the same as the factory)

- This means that when the car is idling (thus not making boost) the PCV will create a vacuum to relieve crank case pressure

[The Dan]

Just join everything at the catch can. All pressure equalises there. You won't need to get a dual outlet on the cam cover, just run it over next to where the cam cover breathers enter the catch can.

Running the PCV and the air intake together like you have suggested is the absolute best method.

And think of it this way....if you can't get it working, you can always get a job as a graphic artist. Those pics are awesome!

[HIRISK]

Hahaha, LOL....you aint seen nothing yet, check this shit out...

So, I think I have TWO options now.

OPTION 1:

Run PCV to catch can

Will require a new fitting welded on the catch can

OPTION 2:

Run PCV to cam cover

Will require a new fitting on the cam cover

I think I prefer option 2, and as long as the overall consensus is that it will work and is right, I will go in that direction.'

From what I understand, they are both correct and, as you mentioned, the PCV will still equalise pressure, even if done via the catch can.

[KiwiRS4T]

Just run the pcv into a T on one of the other lines. I have a slightly more complicated set up with breathers coming from the sump and two catch cans to try to catch most (hopefully all) of the oil and then replace the catch can breather with a line to the turbo intake (breather on first catch can will go into the second catch can).

[HIRISK]

Just run the pcv into a T on one of the other lines.

I was thinking that.

In theory, this should work just the same?

[KiwiRS4T]

I was thinking that.

In theory, this should work just the same?

Yes. Actually you don't need a pcv valve - its just a one way valve and you won't be getting any pressure from the turbo intake so a simple straight through fitting will do. TBH mine is blocked off as it comes from the top of the cam cover (an RB25DET item) very near to the breather pipe and so serves no discernable purpose in my present set up.

[HIRISK]

Yes. Actually you don't need a pcv valve - its just a one way valve and you won't be getting any pressure from the turbo intake so a simple straight through fitting will do. TBH mine is blocked off as it comes from the top of the cam cover (an RB25DET item) very near to the breather pipe and so serves no discernable purpose in my present set up.

I think I will leave mine blocked off for now and just focus on getting the vent to atmosphere replaced with a recirculating set up.

I have been looking at pictures of RB26's on Google all day and the bulk of upgraded ones all have the PCV blocked off.

I am going to make an assumption that based on the amount of modified RB's I am seeing with it blocked, it should be OK.

[SiR_RB]

Option 3: sell me your hard pipe kit