Routing the PCV into the downpipe
 

Me and a buddy are talkin bout this ----, apparantly the supra guys are routing their pcvs into the downpipe. The flow in the downpipe sucks the pcv gas out of the cylinder head, so this is kind of like putting that vac pump on the pcv that someone did earlier. I'm assuming you use a check valve to keep ---- from being sucked from the exhaust into the crank case. What you fellows think, might be an easy way to to get rid of the pcv lines without catch cans or dumping to atmosphere

"Exhaust slashcut evacuation
-----------------------------------------------------------------------------------------

This is based upon the same Bernoulli effect mentioned before but uses exhaust gasses to draw out crankcase gasses instead.

Their are 2 ways of doing this:

1) Weld a slashcut tube in your waste-gate dump-tube
2) Weld a slashcut tube in your exhaust"


"In the first test I connected my Dewyer Magnehelic Pressure Gauge to the slashcut in my wastgate to measure the vacuum draw. As expected I only saw maximum vacuum drawn when the wastgate was open after reaching my maximum boost pressure set on my boost controller. The amount of vacuum went up from 0.25psi(0.5") to 0.4(0.8") vacuum. The numbers shown here were very similar to those shown with the.

"its supposed to use the vacuum created by the exhaust to pull out the pressure. but yeah its still hard to grasp the whole concept of how that works lol. i'm no physicist"

Re: Routing the PCV into the downpipe
 

Its called the bernoulli effect

It is ANYTHING but new.....


Operates on a venturi principal... The slashcut (at an angle... angled side to the rear of the flow) effectively produces low pressure, so the ---- is drawn out . The dump wouldnt do ----... The DP is the way to go if youre going to do it. Enjoy oil all over the back of your car.

---- that ----.


V8 Hotrod guys have been doing it for over 50 years

The excerpt you posted is retarded

Re: Routing the PCV into the downpipe
 

Wouldn't it be better to have it routed to the wg dump so you only get vacuum when you are under boost?

Re: Routing the PCV into the downpipe
 

:1 you basically said that boost creates vacuum.

you want vacuum in the engine, or absence of pressure period

Re: Routing the PCV into the downpipe
 

No, what he was implying was that the vacuum created in the slashcut would come only when under boost (full boost when the wg opens and the exhaust gets routed there, where the slashcut is). I would just put it in the DP or further down the exhaust for the record.

Re: Routing the PCV into the downpipe
 

Yes

Re: Routing the PCV into the downpipe
 

exhaust flows constantly, wastegate does not

Re: Routing the PCV into the downpipe
 

I don't fawkin know, that is why im askin. My catchcan honestly barely gets any oil in it to begin with tho. I'm just wondering if its worth doing.

id doesnt work worth ---- unless the gasses are flowing at a high velocity. thats why v8 dudes do it right after the 4 to 1 collectors in their header.

so if u have a 3inch exhaust go eat a dick

That's why I used to run the pcv valve in the standard setup except for a check valve in place to close off boost pressure, and then T off with another check valve to allow only a vacuum draw from a slash cut. This way you have a vacuum to the motor at all times. I had a drawing of that setup on here from a few years back, it might show up in a search.

DP would work fine as the only time we see positive crank case pressure is under boost when the wg is likely to be open and flowing.
This is not a new idea. works well.kinda sooty for a street car tho.

That unfortunately is not the case. Unless you sit at idle all the time you do build up crank case pressure even when cruising. I used to see this often when I would just dump the breather box vent right to the ground and use a small filter on my valve cover. My oil pressure would start to climb until it hit the limit and then drop when I got on it to "push" the pressure out the vents. Honda's for the most part just don't have enough ports throughout the block and valve cover to let it breathe without a vacuum source...or at least breathe well.