How did you log the pressure? And what graphing software did you use

 

read this its good info if you havent already http://www.dsmtuners.com/forums/arti...cv-system.html

also, i agree with dsmlink forum, theres other things causing your issue with changing the tune not what you did.

if what you did works then it works. every setup is gonna be different in regards to removing crankcase pressure. its a case by case basis.

examples:

isah sleepers 2.4 engine i built has no blowby. hes trapping 137 with a full weight car still on factory crankcase system with a side vented filter on valve cover only.

what worked for his would not have worked for me, since mine sprayed oil into the intake manifold tract every pull & had so much crankcase pressure oil started going up the turbo return line and into the chra leaking out the vband.

my system cured everything + made the car drive better + picked up some hp also.

 

The pressure sensor is tapped into the front O2 ADC input on the ECU, and I log it with EvoScan. Data are plotted with graphs that I set up in Excel.

 

I read that long time ago. there isnt anything else wrong with my car. I see your statement just as ignorant as the ones being made on link forums. my system run sealed changes the tune horribly. and there can be only one reason why. crank case a/f after boost is far different from when it originally enters engine.

 

Mrfred, any chance you could go back to the stock system for a pull for comparison?

 

Sure. I'll try to do it this evening.

 

ok. if you say so.

 

So, I didn't get a log for several reasons:

1) It was going to be a hassle to get a hose connected between the intake pipe and the valve cover.
2) The setup I have now is not going to flow any differently than stock. There's maybe 1 ft of additional hose, and the catch can is not a restriction at all. The main restriction is the size of the orifice in the nipple on the valve cover.

 

Mrfred, sorry as when I read it the first time I was thinking you had the can vented to atmosphere and not back into the intake tube. How about a pull with a single line to the catch can with the can vented to atmosphere and the intake nipple blocked off? Lets see what kind of pressure is building up with the way probably a lot of the people running catch cans are hooked up.

Awesome data though and thanks for sharing.

 

i can do that. i'm gonna zip tie my dipstick to be safe. in addition, i'll measure the vacuum in the intake pipe nipple using the pressure sensor, and for kicks, i'll compare that to baro which is just a pressure sensor in the maf track. look for results on friday.

 

Loads of people run straight up vta systems... Can we cap pressure test with both breathers open and the intake check valve capped?

 

this was your setup and ill explain why it didn't work;

you have the side and rear tapped into the same bottle. then on top of that, you had a 3rd port (outlet) (the black hose) tapped into the air intake pipe. (not in this pic)

why would you even attempt this? did you not realize that oil blowby does accumulate out of the rear (pcv side) and overtime that bottle will fill with oil, and if you have the hose running from the bottle filled with oil, the turbo would suck the oil right into the intake pipe making it a mess.

not to mention, you rely on just that hose to relieve the pressure from that tiny sealed bottle?

of course in that case scenario its going to screw the car up. tune and all.

if you insist on running that bottle, then i'd put a big breather filter on it & open the outlet up more for it to be effective.

in that case though, yes you dont want to run that back to the air intake pipe. it will do nothing but cause problems as you experienced.

if you put a hose from the side valve cover port into the intake pipe you might see the tune won't be affected. its worth a shot. it did not affect mine at all. but never link the rear to the air intake pipe like you tried.

 

94coupe do this and you may be surprised with the results in a positive way.

take that bottle and run a hose from the intake manifold with a one way check valve from http://www.usplastic.com/catalog/item.aspx?itemid=36844 allowing flow only towards the intake manifold, so the bottle does not see any kind of pressure from the intake manifold when in boost, then take another hose from the rear valve cover side and add a one way check valve to manipulate a pcv functionality. then what you have is a bottle inbetween the intake mani and valve cover. you still get a factory like functionality but now you have a bottle catching the oil before it enters the intake mani.

then take your side port and run that directly to the air intake pipe. if there is good enough baffling , you won't ever suck oil in the intake pipe. mine doesnt ever. or just put a breather filter over the side port. from what i recall though, that valve cover you have will shoot oil out the side, so maybe do the fuel filter mod other dsm guys do to catch the oil.

your old setup is designed for a vented setup only, you can't run both front/rear into a sealed setup as you experienced first hand.

 

Can I use the intake pipe just before my TB as a vacuum source? I'm planning on mounting my catch can right by my battery. I have an odd turbo placement (its on the passenger side of the car) so routing a line just before the turbo is a pain and next to impossible (its really tight). I've already put the AN fitting on the pipe, so i hope it will work.....

 

No, you will presurize the crankcase with boost.

tscompusa, the DSM (or EVO 3??) valve cover baffling doesn't work all that well. His results are not likely to be similar to an EVO either way.