does anyone know where to get the press in fitting for the stock pcv side so i can use the stm 6an fittings? i had removed mine to install the buschur can fitting.

 

I think the stm fitting just press directly into the valve cover but if not stm also has a bushing in the oem section for that side. But like I said the fitting just presses directly into the valve cover and the 90 with the black fitting they have a picture of on their site is just to show the old setup.

 

The STM -6 fitting on the PCV side requires the collar he is talking about. You can remove the collar and run a -10 fitting though (Fairclough). I don't have ASA on this machine so I don't have part # in front of me. I got one through the dealer at one point though so I know they sell that collar separate.

 

yeah im talking about that collar.

 

rocker cover collar MN158504

 

On my setup I see positive pressure coming from the exhaust at idle.

 

thank you very much.

 

Really? Mine feels like it... But take a robber glove or baggy and put in over the end and semi seal it... If the bag blows up then its pressure... Mine vacuums out...

Its all back together and i tried to take off my oil cap with the engine on... It suctions the cap back down at idle... Craziest **** i've ever seen... But at the moment i have the pcv and evacs running at idle...

 

I will try as you suggested. I essentially put my finger over the end of the tube and feel air pulsing from the tube. However, if there are pulses of positive and negative pressure then the rubber glove would let me know which is the dominant affect.

I ditched the stock PCV so I have to rely on the exhaust scavenge and turbo inlet for all block evacuation.

 

I finally got around to trying the configurations in the sketch below. As noted in the sketch, the amount of vacuum was essentially zero in all three configurations. This was observed for idle and off boost driving. The strongest vacuum, if any, was observed during idle. The lack of vacuum for the first config wasn't surprising. I was able to occasionally see a blip of -0.75 psi vacuum in the interrupted flow configuration, but the standard soda straw configuration was definitely zero or slightly positive. I eyeballed the 45 degree angle on the nozzle for the soda straw configuration, so I will check that and if needed, adjust and retest its performance. I may also tinker with the amount that it pokes out into the exhaust stream. And I will also try out whistle-style configuration shown below.

Just as an FYI, the pressure sensor I used registers the exact same values as my MAP sensor when I plug it into the intake manifold.

Configurations that I have tried.


Whistle style (have not yet tried)

 

The angle on the scavenge tube was good, and in the soda-straw or whistle configuration, the scavenge tube appeared to be about 3/16" into the exhaust stream, which I think is an optimal depth.

The whistle configuration was no better at producing any sort of vacuum. By my pressure sensor, it was 0 to +0.3 psi for idle and off-boost, and at WOT peak power, I measured +1.5 psi. Pulling the hose off the pressure sensor, I felt clear positive pressure pulses coming out of the hose in both the interrupt and whistle configurations. A paper towel or a plastic sheet were both repelled by the pressure pulses no matter how close I brought them to the hose.

joseph143, if you have any detail pictures of the angle and penetration depth of your scavenge tube, I'd love to see them.

Overall, this was a rather enlightening but disappointing experiment. I was really hoping to be able to ditch the manifold vacuum setup. Unless someone has something they want me to try, I'm dismantling the setup on Sunday. Here are some pics of the setup.


Baseline configuration



Whistle configuration



Bung on testpipe



Hose leading up to engine bay - If anyone is curious, the hose did not melt during typical around-town driving.



Hose attaching to Kavlico pressure sensor

 

I was thinking about this a little more, and I am wondering whether the positive pressure pulses are unavoidable and that the way to generate a vacuum is to use the check valve so that positive pulses are repelled and only vacuum is applied. I guess I'm going to buy the NAPA check valve tomorrow and test out this concept.

 

Damn fred! I've been working a **** load recently and havent been on much... I would agree with the check valve 100% its 20 bucks... Also my kit is installed WAY closer then yours idk it that effects anything...

Where can i get that sensor? I've been lookings and cant source one... Mine definitely pulls vacuum... And the other day i installed it backward... By that i mean it was bevel into the stream rather then with it like your number 2... And i still created enough to vacuum my oil cap down at idle...

Here in a few days my turbo should be back from the shop... When i drop my downpipe i'll txt you some pics and see if i can help you in any way... Maybe the depth of yours is wrong... Iknow the highest velocity air is away from the wall... Maybe 3/16 isnt enough... I never measure my depth so i couldnt say for certain... Soon...

 

i have the buschur catch can. its not bad