Rb26 Catch Can Piping

[IanB]

Hi all

I have recently installed a catch-can to my 26 and have since had all sorts of weird hesitation / missfiring / random stalling.

Heres how I have it plummed up (From left to right)

Pipe from plenum area to drivers side breather: Left in place

Both left and Right side breathers are now piped into catch can

Pipe from passanger side cam breather to turbo intake pipes: Blocked

Now from what I know, the pipe from the plenum side of things only opens on vacume, on boost it closes up, which is consistent with my problems only happening off boost. What I think is happening is that air is being sucked through the catch can into the intake manifold off boost and hence not going through the AFM's, causing my missfire etc issues? Most of the time, if the car missfires or gives flat spots, clutch in and rev's will fix it, or getting some boost into it will fix it.

What I want to know is, if I put a 3rd line from the top of my catch can back into my intake piping, where the old pipe used to go, will this fix the issue and will the catch can still work?

Thanks in advance

Ian

PS I have dodgy paint diagriams of what I mean, let me know if you need them...

[blind_elk]

Is the can sealed, or does it vent to atmosphere?

If it is sealed (which it should be, so it is an oil / air separator), I suggest you plumb it as:

Rocker vents -> catch can 'in', then catch can 'out' -> turbo intake

[IanB]

No, it has 3 ports, 2 for the rocker vents and a filter on the top.

I was thinking of pulling the filter off and running instead of the filter a line back to the turbo intake...

The can is empty however, theres nothing in there. Will it still work?

[OFENSV]

yes its because you have a breather on your catch can causing it to suck through that and run lean. Either pull out the pvc valve and block it off and have it a full venting to atmosphere setup which is illegal, or plumb the breather back into the inlet piping before the turbo.

[IanB]

Is it illegal even if theres a filter on the can?

I was thinking of building a little box to put the filter in and then running the line out of that into the turbo inlet pipe. Would this work?

[r33cruiser]

yea the breather is illegal:

here is some help

http://www.boostcruising.com/forums/index....howtopic=265183

[IanB]

Very helpful thanks

Im now running the "100 % plummed back" option, I think its the safest, the others are bound to stuff with my tune and cruising.

[blind_elk]

The can is empty however, theres nothing in there. Will it still work?

Try stuffing some steel wool in the can. It will act as a "seed" for the oil vapour to condense around. After all, the purpose of the can is to remove oil vapour from the air.

[IanB]

Yeah read that, going to grab some stockings as well because im not overly keen on the idea of bits of the metal wool coming loose and going through my motor...

[R.3.2.G.T.R]

^^ pics of your catch-can setup if you can plz.. would like to do the same shortly