Ever since blowing my dipstick out (twice) at the track I've been looking to improve crankcase ventilation; my DIY air-tool inline-filter catch can wasn't working very well anymore because the heat had caused the filter to melt slightly and become very restrictive. I looked around for an oil catch can with two inlets (one for the PCV hose, one for the crankcase breather hose) and one outlet or breather filter and found this inexpensive solution from Road Race Engineering (RRE).



It has two inlets and a breather filter built into the top, and also an easy-to-open drain valve on the bottom.

It comes with an aluminum mounting bracket that I modified (hammered flat, folded and drilled) to look like this:



With a small or relocated battery and an aftermarket upper intercooler pipe, the catch can mounts neatly next to the engine, near the rear throttle cable bracket using existing bolts (the upper bolt for a wiring harness, the lower for the large throttle cable bracket).





As you can see the location is ideal because it minimizes the lengths of the two crankcase vent hoses. I capped the nipple on the turbo inlet tube where the crankcase breather hose used to go and capped the fitting on the intake manifold runner where the PCV hose goes. (Actually I hooked up my boost/MAP sensor hose to the latter fitting and deleted a tee I had on another hose.) I turned the PCV "elbow" fitting around 180 degrees (basically it's a friction fitting--just grab it and turn) and the PCV hose routing is just about perfect--a straight run to the catch can.

I also deleted the PCV valve by replacing it with a straight-through fitting. The PCV valve normally prevents the air in the intake manifold from pressurizing the crankcase, by closing under boost. However this means that the PCV hose can't help vent the crankcase under boost; since the PCV hose is no longer connected to the intake manifold, pressurizing the crankcase is not a problem anymore (in fact the PCV valve may never close) so the PCV valve can safely (in theory) be replaced with an open fitting that is less restrictive and less prone to jamming/clogging and should therefore improve crankcase ventilation.



The thread specification on the PCV valve is 1/8-27 NPT; the hoses I used were 5/16" oil/fuel line hoses.

 

Nice job - Did you take off the L fitting to which the PCV is attached altogether or did you leave it and attach your barb fitting to it? Thanks!

 

I turned the elbow fitting around 180 degrees, unscrewed the PCV valve from it and screwed in the barb fitting (1/8-27 NPT).

 

I will look into doing something like this later -- nice work, Tam! How come you're posting this stuff here and not on NCE? Don't bother right now, some ******* hacked the site about an hour ago and now it's down.

 

^^Guess that's why he didnt post it lol. Looks pretty good!

 

The pictures arent showing up?

 

They work for me (and other people too). They're hosted by JustRacing.com; can you get there?

Dave, I guess you missed it, I posted this on NCE yesterday morning.

 

Have you blown your dipstick out since you changed to this? Im having the same problem.

--Josh

 

hmm, I have this same catch can, maybe I will reroute the pcv valve and delete it as you did...

are there any negatives to deleting the pcv valve like this?

 

I'm curious why you need a catch can at all. Can't you just run a tube down and out the undercarriage?

 

you can but if you ever track your car, you wont pass inspection at most tracks....

I made my own catch can and it only cost me about 10 bucks (had most of the supplies already) and i think it looks 100X better that rres catch can...there reallyeasy to make

 

The new setup is working well but I don't know about the dipstick because I zip-tie it in place now, just to be sure. At any rate, I've had no more oil leaks in the two track days I've done since installing the catch can.

The PCV valve allows the crankcase pressure to vent into the intake manifold, while preventing the intake manifold pressure from pressurizing the crankcase. Since the PCV hose is no longer connected to the intake, the PCV valve no longer gets closed by pressure from the intake, so it doesn't do anything other than restrict the hose.

The "negative" to this setup is that it's not emissions-legal because it allows vapors from the engine to escape into the atmosphere without having gone through the emissions control system (cat)--same reason that a VTA BOV is not smog-legal.

That would be a bad idea. Oil comes out of those tubes. You don't want to dump oil on the road/track where it becomes a hazard to other drivers, and you certainly don't want to get oil on your own tires.

 

so the pcv valve delete dosent cause any ses lights does it....

 

Right. I didn't realize you guys were planning on tracking it. My other car dumps to the ground. But I don't get any blow-by anyway.


The valve is simply a check valve that only allows air/fluid to pass in one direction.
I don't believe there is any sort of error detection built in. I can't think of any reason why anyone would. It's not a sensor. It's simply a valve to vent air/oil.

 

I don't think so--there's no sensor attached to the PCV system (as far as I know) so it'd have no way of knowing.

But I long ago removed the SES light, and I usually kill power to the ECU with the master switch, so it's unlikely I'll ever see any OBDII codes from it.