Oil Catch Can Installation Quick Question (searched)
 

Hi, just a "side question": I am going to run a non-vented catch can.
Can I use the hose that is on the lower nipple on the stock Oil filler neck and attach an extension to that hose go to the catch can, instead of running a whole new hose from the catch can to the primary turbo intake manifold nipple? I would of course connect the nipple to the catch can.

To clarify: Oil filler neck to catch can, catch can to hose that attaches to existing hose that is presently connected to the filler neck.

I would use a barb fitting to join the hoses.

Let me know and thank you.

Giovanni

I've wondered about that in the past. I think the potential issue with the lower outlet is that it may be too low and you'll wind up getting too much stuff into the catch can. Especially if you are using the car on track or autox.

You could experiment for yourself and see.

I run a non-vented catch can and I use the nipple on the oil filler neck, run to the catch can, then catch can to the intake. I don't catch much in my catch can and I don't have any problems with my set up. I run a single turbo.

I don't see any problems using the lower nipple. I do have a REspeed filler neck to prevent oil from migrated up the neck of the filler tube.

Thanks guys, I had a different concern, however, I probably did not explain myself properly.

My intention is to use the upper nipple as I had already plugged it before (no PCV).
If that proves to be too low, I'll do what some have done, which is to tap the filler neck's cap.

My question is this: instead of running a whole new hose from the catch can to the nipple on the primary turbo intake nipple, can I run a hose from the catch can to the existing and now disconnected hose, use a barb fitting to join the existing hose with the hose that comes from the catch can, leave the other end of the existing hose attached to the primary turbo inlet nipple and be done with it?

Giovanni

You can use the existing hose if you want to. I eliminated the PCV valve and run only one line from the filler neck to catch can, catch can to intake.

The later model rx7's did not have the PCV valve running to the UIM. I haven't had any problems with mine running it this way both with NS stock twins and my single turbo.

Thank you, that's what I was looking/hoping for. As much as it seems to be obviously possible, I have learned that sometimes, with this car common sense and logical thinking don't always apply.

I'll complete my installation shortly. We still have snow and salt, so I'm not sure I can test it soon, but... we'll see.

Giovanni

May i ask what size hosing would be appropriate? im looking at cusco catch tanks and im not sure if either a 9mm or 15mm hosing would be good.



i would measure myself but im far from my FD right now.