OVTune 3.5L Tacoma Supercharger and Twin Turbo Systems

My '97 N/A Bimmer came with one OEM. Except the oil drains back into the pan.

 

Glad u mentioned that. I've gotten such little quantity out of mine I was beginning to form an incorrect interval in my own mind. Cold weather having more blow by is counterintuitive in to me.

 

Condensation/steam. It collects a lot of water

 

It doesnt get cold in Arizona..

 

I don't do well in the cold!

 

Is it necessary to replace intake manifold gaskets when you do the direct injectors?

 

Breather from pass valve cover has to go back into the intake side(not the intercooler pipe side which is pressurized).
It’s extended, runs under intake manifold and then to a custom port I plumed in right after the intake filter.(don’t mind the weld, all pipes are getting powdercoated)

I don’t see a need to. Mine were fine. Just clean up the surfaces because there will be some oil and gunk residue.

 

So you have it going pre-turbo? Aren't you worried about the turbo pulling oil vapors into your turbo vanes? If you do that you should run a 2nd catch can because oil will come out of that line under boost. Oil on your turbo is going to eventually mess your turbo up.

So under vacuum the driver side pcv should vent and the pass side should breath in from the intake. Under throttle (or non-vacuum) the driver side PCV should close (if it has a check valve - not sure if this engine does), and the breather will now blow out.

Add boost and things change. Crankcase pressures increase as does blow-by. Under vacuum all is well. Under boost and you now have extra pressure in your manifold pushing on the driver pcv side. On the intake side you have two possibilities: pre turbo - you have the turbo speed sucking gases out of the crankcase and oil will come with it. Post turbo you now have boosted air pushing down your intake which can push air into your crankcase since the pcv side is closed.

Hope I worded that right to make sense.

 

How did you relocate/reclock your oil filler neck?

 

Wont that draw unmetered air? I thought everything needs to go pre maf to be properly running. I might just make things easy and just VTA both valve covers with its own catch can. Wont smell nice though

 

Our trucks already pull all crankcase gases post maf anyway. Pre maf is better as MESO has it, but needs to be filtered with a catch can. Especially since any oil will dirty the turbo and the MAF sensor. I seriously doubt the internal baffles will do their job. My breather line has oil in it and it's not boosted.

With VTA through a catch can on both sides you could run both through 1 catch can and shouldn't be messy. But yeah you'll smell those hydrocarbons and oil.

 

I take that back. I just remembered what I wanted to do on my turbo 2nd gen and didn’t get a chance but do it on the TT kit. Gonna run E-vac scavenger kit.

 

Put an angled bung on one of the down pipes. Exhaust creates a vacuum venturi on that bung.

Vent filter on opposite valve cover from dump bung. Adjacent valve cover routed to dump bung(catch can could/would be placed in line with this hose). Vacuum cap intake manifold amd other ports where connections to PCV or valve covers were. Done.

All out of the exhaust, all post turbskis.

 

Yup. Easiest way to avoid going back into system. It’ll just burn off whatever isn’t caught in the can.

 

I didn’t think of the turbo sucking in that much vapors... but with the increased crankcase psi it could be more than I thought. AFAIK The final twin turbo kit is plumed from the vent to intake(post maf?)
I’ll prob throw another catch can on it like your guys mentioned. Or look into that Evac scavenger.

thanks for all the input.

stock filler neck. Just a diff cap


Edit:
Ordered a mishimoto catch can. I’ll feel better having it between the vent and intake

 

One of the things you can do, which is what I will likely do to maintain a closed system, is go with a dual valve catch can. The normal ones are fine for N/A engines but since they only scavenge on the vacuum cycle they aren't quite enough for turbo engines unless you run two catch cans. The dual valve ones are more economical because they have one can with 3 ports. Some even come with check valves built in.

- one line comes from your valve cover
- one out to the manifold for vacuum scavenging at idle
- one out to pre turbo for throttle scavenging

Something Mat said was that this turbo set up is in boost pretty immediately even under light throttle. That alone will make something like this a little more applicable.

I'd say the E-vac scavenger is better and pretty much zero maintenance, but for the average installer who doesnt want to fab their exhaust, catch cans will do fine.

 

I'm a visual person so I like to draw things out. So here is what I plan to do and why. Color coded for easier understanding.

At idle the manifold will be in vacuum and will pull air through the catch can from the pcv side, which subsequently will pull air into the crankcase through the breather port on the other valve cover from the intake which is at rest. This is how it's meant to be normally so you don't create negative pressure or vacuum inside the crankcase. I want to maintain this while using only 1 dual valve catch can.

So I would run a Tee from the breather to the intake and secondary valve of the catch can to allow it to do this under vacuum. Now here is where things get crazy.

I need 2 check valves (designed for boost - so gradual apply and strong enough to withstand boost pressure). 1 will go between the manifold and catch can. Check valve 1 is detrimental. It will keep the manifold from boosting your catch can and crank case under throttle. A pcv valve will do this but whatever is on this truck is not designed for boost. Failure to do this will create a 'boost leak' and introduce boost into your crank case.

Check valve 2 is not necessary but just piece of mind. This one will close under throttle to ensure blow by gases and oil don't get pulled into the turbo (though this isn't likely to happen since the catch can is already doing this). I just want to create a path of less resistance from the catch can. This will also allow it to act as a breather still under the right conditions.

So with this setup under boost the manifold port closes and the new rush of super sucked air from the turbo acts as the vacuum which will pull air through the catch can's secondary port and from the pcv side. The pcv side is always flowing one direction whether under vacuum or boost so no check valve needed.

No breather should be necessary under boost since there should be an increase of blow-by gas from the turbos and the vacuum created by the intake is pre turbo so it should maintain equilibrium. The breather is mainly there to assist the flow under vacuum. In instances where the crankcase demand is more than the turbo vacuum effect, it will still act as a breather.

 

RX Performance makes nice catch cans for any application...if they don’t have it they will make one. They made one for my SC Tundra the truck was using oil under boost but not anymore.

 

Is the smaller can a CSS (clean side separator)?

 

Good find. Looks to be about the same routing/setup @JamesT is going to do