guigson

Hi everyone,

I have a Mishimoto closed loop catch can installed between the breather port and the crankcase vent port on the air intake elbow right before the supercharger. The PCV valve is not capped and is still connected to the intake manifold.
This was installed by the previous owner and I have no idea how long it has been on the car.
I have not seen any oil accumulate in there in 3000 km or so. I assume either:
1. There is zero blow-by - no way
2. The catch can is badly designed and the oil vapor doesn't condensate and stay in the can - possible
3. This can setup is bad for this application - maybe, there are a million catch can threads and they all say different things

Although the can is different, it is the same setup as the Radium 19-0062. The Radium website says it is compatible with forced induction setups. Here is the installation guide, I compared the installation steps with what I have on my car and it matches.

Anyone willing to help me figure out if this setup is adequate for this FI application?

Thanks

engifineer

Cannot speak as much to the FI application. But I never see one drop of oil in mine from street driving. I only have the PCV side connected to a can but the PCV side is typically where you will see more oil. But I see oil in the can only if I am autocrossing or on the track. To be honest, I see a lot more at an autocross event, especially a practice with tons of runs. But that is due to the AP1 PCV design and how oil gets "Sloshed" into the PCV system and of course is very course dependent.

For forced induction, I would think you would see a bit more, but still more out of the PCV side than the front breather. But others with FI setups can speak to that.

My approach is that a catch can is not only worthless for street driving, but just creates more headache (like needing to disconnect it during long storage periods or emptying it much more if driven in cold months to avoid condensation buildup which gets back into the valve cover). But again, it may be more useful for FI folks on a regular basis.

guigson

Alright, so if I were to remove the catch can then I believe the purple line I drew would be the proper reconnection for the breather port.
This seems to be what an old installation manual I found for the comptech supercharger suggests.

spdracerut

You won't see anything from the front breather. You need to plumb the catch can to the PCV. In street use, you hopefully won't see much. In road course use is where I'd see oil collected from the PCV, not the front breather. The purple line you drew is correct for connecting the front breather, to the intake going to the blower. Now you'll want to run a line from the PCV to catch can, and the other to the intake mani.

engifineer

Here is a reference from my car of the routing from the PCV to my cheapo catch can setup. You probably already have that figured out by the description, but pics never hurt

guigson

This is what I would expect, but it is not what Radium describes in their S2000 specific installation manual. I will try this for the rest of the season.
I'll set it up like engifineer. NowI have to figure out if I can mount it at the same place as him and reinstall my cruise control.
Thanks.

SlowTeg

A few thoughts on the catch can setup.. Here's a shot of mine. I used cheapo cans vented to atmosphere.



As Khiem pointed out, the middle pcv port is the one that tends to accumulate the most oil. To note, I also have done the RainH8R style valve cover mod. It helped tremendously cut down on filling up the catch can I used to have when NA. I'm assuming it helps as well now being boosted, but I'll note I get more oil in the catch can now that I'm boosted. Also as noted, I get little accumulation on the street, but on track I filled up the small catch can for the PCV location in 2 sessions.

A few more thoughts.. Why vented to atmosphere? A couple things. #1 being I want to avoid any oil in my intake path (if it slips past the catch can). Any oil in the combustion chamber lowers the octane rating of the gas which can lead to knock. #2- I'm not a big fan of the pcv location being routed back into the intake with a boosted car as there's more crankcase pressure to bleed off and you're leaving it all upto the front VC port (since the PCV valve will close under boost) to relieve all the crankcase pressure. Yes, there are a few different ways to tackle this. Instead of venting to atmosphere, you could use a high quality catch can with good baffling and it should minimize/eliminate all oil vapors in the air. I am a little concerned about this setup though because if the catch can fills up and you don't notice it, the oil will have no where to go but the intake tract. No bueno. During my last track day I was able to notice it was full as I had some oil that was pushed out of the catch can in the engine bay. Not too big a deal, better than being ingested by the engine.

There are a few different ways to skin this cat. I don't think there's a "100% correct" way to tackling crankcase venting. Different tradeoffs and considerations to factor in. A better approach would be to modify the valve cover and install larger ports imo. The OEM PCV location isn't that large of an opening nor is the front VC port.

engifineer

May be harder to fit your can in there as it looks a tad bigger. I made that mounting bracket for mine out of a piece of flat stock you can get at most HW stores. I had to put a slight twist to keep the can vertical since the shock tower is slanted and it was just thin enough to provide enough threads for the shock nut to still work properly. I also added a small amount of foam behind the bracket in the case it vibrated against the shock tower to prevent it from wearing paint off. But otherwise it worked out well as I did not want to relocate or remove my cruise control.

spdracerut

Interesting, what do their instructions say? Basically, on any car, you want clean air for the front breather and non-pressurized. So that's why it's after the air filter and before any forced induction on any OEM car. The first time I tracked my car with my ram air duct, I did not plug the hose going from the intake to my catch can to the front breather. I basically lost half the pressure gain from my ram air duct as that pressurized air went through a path of least resistance being the front breather. The next track day, I plugged the front breather and gained the full pressure benefit of the ram air. I could modify the setup and put a check valve in the front breather. Or the setup of just a hose to a catch can with filter vented to atmosphere.

https://motoiq.com/project-s2000-par...intake-mods/5/

Alternatively, you could just put a small air filter right on the front breather, assuming the risk that if any oil goes out of the front breather, it will eventually make its way through the filter and into the engine bay. Putting a catch can on the PCV and also getting suction from the intake manifold, it will only pull oil when you have some vacuum in the manifold. Under boost, the PCV closes of course (hopefully). For NA use, there is still some vacuum in the intake manifold during full throttle.

s2000Junky

OP If its not broke, don't try and fix it. You wont get much of anything out of the front valve cover breather port FI or not. In fact I personally just ran a filter there because it would be so minimal to nothing, and just leave the pcv stock as you are doing. Where you will get issues more specifically to the ap1 valve cover is through sudden back and forth hard G corners from spill over past its poor valve cover baffling and the oil would slosh past that and come out the breathers. This is what the catch can is primarily for. If your not autocross racing, with R comp tires there good chance you will never see that problem on the street, so I would just leave your current catch can as it is. It can only help in severe case, and its not hurting anything.