93FD3S

So is it going to suffice to just vent the catch can? Or is it really necessary to tap into the Intake? I really don't really have anyway to tap into the intake, no place either on the filter or silicone coupler. Only room on the intercooler pipe after the compressor.

RX-Heven

iTrader: (1)

Just vent it then. You could run a filter right off the can or a hose from the can to a filter. Either way.

93FD3S

Thanks ...!!

apneablue

I installed one 2 days ago...Did multiple pulls to redline and no more blow by. I got the one from Gotham Racing for $57 shipped to my door. Chromed and well put together piece. Had to fabricate my own bracket for it but that was half the fun.

93FD3S

apneablue, did you vent your catch can or run a line to the intake?

apneablue

I just left it vented...But interesting that you say this. There is an outlet that comes off the catch can that I just left open to the atmosphere. Do some people route this back to the UIM?

Also, if the crankcase vents under pressure, does it also pull a vacuum at times? I have noticed that some people put a filter on the vented portion of the catch can. Is this necessary?

CrispyRX7

iTrader: (139)

The oil pan never pulls a vacuum.

And for some, the "blowby" you refer to is not necessarily an issue of WOT in a straight line but "blow by" into the catch can under sustained high G-load cornering - namely left turns .

Regards,
Crispy

apneablue

Crispy,
So is it possible that you will still get blow-by under accelleration? The first time I really noticed this was on the Dyno...Then after that I noticed it on the street when I accellerated hard through 3rd or 4th...Since I put the can on I haven't noticed it. Just wondering if its coincidence that I am not noticing it or I have another problem.

ghostrx7

Im using a fuel hose line vented to dump under my car btw its connected to the oil filler neck ..., open to atmosphere...so far so good...wondering if this is optimal or should I spring for a catchcan?

CrispyRX7

iTrader: (139)

It's possible that adding the catch can is doing it's job of baffling the blowbly or creating enough a restriction yet still venting to the intake or atm. that you aren't noticing the blowby as much. On the stock PCV system the intake system is constantly "pulling" gas from the oilpan either from the connection to the UIM or from upstream of the turbo inlet. If the oil pan is vented to atm it will see atm pressure. Cork any oil pan "vent" and believe me the pan will pressurize and you car will smoke like crazy. The smoking coming from the back pressure from the oil pan back though the turbo oil drain line (normally gravity fed) causing the turbo bearings to leak and hey presto oil smoke out the exhaust pipe.
As for your car I admit I haven't been folling the thread so don;t know the details of your situation.
Food for thought,
Crispy

AntiVenom7

as far as having to empty the can has anyone thought about rerouting it back to the oil pan so you dont have to constantly empty at the track? i still haven't installed mine so i am not sure if this would work at all.

93FD3S

I'v also noticed that even at idle my FD hardly smokes anymore with the catch can. I have the can vented with a small stainless steel mesh breather filter.

4CN Air

iTrader: (7)

so the simplest setup is running the line that goes from the oil filler neck to the UIM to a vented can?

is this is correct then why not just reroute this line to the oil pan? won't release pressure?

APEXL8T

I understand the reason why you want toplace the tank line to the suction side of the turbo
but does someone have a pic or exact location description. It seems that any placement on the comp housing would be in boosted air except for the intake lip.Is there a portion in the housing that is in the draw/vacume?

manatecu

iTrader: (6)

There are multiple ways of doing this.

You can tap the compressing housing in front of the blades. You will need to cut the filter rubber connection.

You can extend the housing with a metal tube (diameter of housing) and attach with silicone houses. Tap the metal tube.

You can use bulk fittings and tap the end of the filter. This is the method I did because it was easy. I will try to post a picture later.

Chris

apneablue

What's the breather for if there is no vacuum being pulled on it? This is a legit question and not trying to be an *** btw.

Also, is there any reason not to route the vented side of the can back to the UIM with the check valve in place?

93FD3S

Thats a good question it would seem like it work better routing the line back to the upper intake manifold with the check valve. But it seems like the check valve isn't doing its job adequately, at least with a single turbo setup. Because before the catch can install I noticed large amounts of smoke under boost and pretty noticeable at idle. Now with catch can installed smoke at idle is cut down to about 50% less and no more large amounts of smoke on boost. As far as breather filter I would think its more for looks then functionality. Correct me if I'm wrong.

black93RX7

Does anyone else get smoke in the interior of the car during WOT?

Whenever I boost the car I get excessive smoke in the cabin. The only thing I can think of is my return line is leaking under boost and the oil is hitting my manifold and causing smoke in the cabin. I am running a braided steel return line from my t78 to the block, it is secured with clamps.

I had to replace the rubber line that came with the turbo kit after about 4000km due to excessive heat and leaking. Does anyone know the exact size this line should be, 12 an?The braided steel feed line also failed after only 3000km.

I have a line running from the oil filler neck to the uim with a check valve. Could this set up not be venting the crank case enough?

I was thinking of just venting the pressure to the atmosphere to see if their is any difference.

Thanks
Erik

KevinK2

The breather is for exhausting only. The UIM checkvalve path is only for part throttle, no boost, and is a small flow amount.

For high blowby that comes with high boost/power, best to eliminate the check valve (that blocks one vent path under boost) and vent both filler neck nipples to the catch can. The actual nipple holes are small, and could be opened some. Crispy added a vent to his oil cap. The 2nd turbo drain can be another vent, very effective for road racing.

Note: if you have bad rotor seals and more blowby than an elephant drinking dark beer, then you will be a smoker and will quickly trash the turbo seals, even with all the above passive vents.

4CN Air

iTrader: (7)

so a catch can is not needed with the stock twins? what about when non-seq?

apneablue

So basically you are filtering the air that you are venting....So it's like an environmentally friendly catch can

wickedywick

iTrader: (3)

back from the dead

I finally noticed I had oil spewing out of the nipple on the center iron. Can I just block this off or T it off to the oil neck and into my catch can? Seems like someone tried putting a fitting in it

KYPREO

There's a very good thread here discussing the way to properly plumb a catch can on a turbocharged rotary: How to properly setup an oil catch can (Bumpstarts Guide) - AusRotary - navigate past the first page, as there are lots of useful diagrams.