808Bill

Yes, I got that. My brainstorming obviously went without much thought...Fouling the MAF has been on the back of my mind with this set up, but maybe it's a non issue?

I like your idea and look forward to seeing if it works.

Silk

Then the only possibility after MAF will be just before the TB. Otherwise you have the original situation. You will dirty your MAF with ‘unfiltered’ cranckcase fumes in that case.

sweet victory

It very well could be a non issue. The previous owner ran a k&n intake, and in his service history had to change the MAF two times after the "upgrade." I've since had to replace it once during my ownership, and then I swapped in the 997 3.8 intake. No MAF issues since. That being said, an oily k&n filter is completely different than this application, but it still leaves a bad taste in my mouth when it comes to putting something oily upstream from the MAF. A new MAF is heck of a lot cheaper than a hydrolocked engine, so I will move it there if there are no other viable alternatives.

Silk

there is a full size hole in my airbox and the rubber hose is squeezed through.

This has too small all diameter to keep the airflow going

Silk

The air filter keeps most greasy dirt out. But you are right. Eventually it could dirty the MAF. I noticed some degradation on mine after 30.000 miles. So I just replaced it. As it is one of the most crucial sensors in the whole system, nothing beats the performance kick, back to original, as a new MAF. I see it anyway as a wear item.

Cleaning MAF is just temporary effect. They all eventually degrade. You should be surprised how much stronger all of your cars wil pull with a new MAF (given it was a long time ago replaced).

A new MAF is sometimes one of the cheapest ‘performance upgrades’ you can do.

Scott at Team Harco

I will assume you're referring to the picture I posted. My plan is to go with larger fittings and hose on the outlet side. Your later suggestions (below) are excellent.

I like this idea. Simplifies everything. One hose directly from the AOS vent to the air box is brilliant. The condensate will simply roll to the other end of the box and out the drain holes.

Great information. Thank you for revisiting this thread and providing your valuable insight.

HoustonCgrBkr

If this is a solution why do we need an AOS?

Silk

I would not use anything with a smaller diameter then 0.5inch.
you really need a free flow without bottlenecks to prevent pressure build up by the naturally blow by of the engine.

In the originaliteit situation with the butterfly valve in the TB open the AOS in full operation gets a higher vacuum/suction (also due to the venturi effect of the incoming airco’s at the vent line location at the plenum) for the cyclonal
separation to do its job then at the relocated place in the airbox. That is why the diameter of the tube should be not too small and also not too big. As the air flow will need to bridge a longer distance to a somewhat lower average vacuum position. You will want the air to be moving freely and but still fast enough.

Here lies the inventive part of the modification. To get the airflow right there to keep the AOS in its operating window. I did not design the modification so I am not aware what the special requirements are.

The extra venting on the oil cap is just a safety in case something gets blocked. At least it will prevent for some too high pressure built-up in the cranckcase.

Silk

You will need the overpressure of the cranckcase out and the AOS keeps functioning. It will separate the oil from the outgoing airflow. In fact you need to look at the AOS as a smart catch tank with a built-in shut of valve to close it when subjected to too high suction force from the engine intake.

With this modification you will take this excessive vacuum situations away. The AOS wil stay open all time. No more problem with a failing diaphragm.

I am not saying that the modification is the ideal solution. But for me it saved my engine at least already once from massive hydrolock. The previous owner of my car needed to do a rebuilt due to a cilinder scraper and a small twist in the cranckshaft. Probably also a hydrolock issue...

Besides oil the AOS could spit out a lot of dirt up till solid pieces which collect in the plenum. So there is more to it then hydro-locking alone.

Dana Whicker

Silk, Sorry if this is mentioned already but what is used to block the intake port in your setup?

Silk

Leave a piece of tube connected to the plenum and cap it off.
Used once a screw which fitted neatly in the tube and used a clamp to secure it properly. But feel free to use your imagination.

Scott at Team Harco

It looks to be capped off (inside yellow ring).


This is very similar to what I did with mine. Will now change mine slightly, to get the AOS out directly to the air box.

jyoteen

thought this would be appropriate to post...


I will probably add a catch can on my new engine build if I can fit it in there.

Silk

The diameters of the catch can connections is of utmost importance. Those shown on the pictures are too small. No free flow secured. You probably will need to modify an existentiële catch tank, drill wider entries and fit custom imkers and outlet with appropriate diameter.

All my catch tank catches is condensation.

Scott at Team Harco

I bought that same "$100" catch can for $18 on Amazon. Agree with Silk's comments - it needs larger ports.