streckfu's

There's the confusion.

The kit does not really add anything. It merely replaces existing hoses. The only difference is the AOS line.

If your mechanic removed the hard venturi line, he had to use these hose. If he did not, what's the point? It's so much more simple and clean without that damned thing in there.

The DareDevil

Doc, didn't Porsche eliminate the venturi tube in '87?

streckfu's

Not until '89 or so as my '88 had it.

The DareDevil

Ok thanks.

flyguy

ok, am more than halfway through this on my 86. have the 3 hoses as from lindsey. The only thing that I dont have now is what I BELIEVE is being discussed here. In all of the documentation up to this point, the hole in the J-boot that connects through the hard lines (now removed) to the Air Oil Separator, is plugged; and there's no mention of what happens with the AOS.

1) what happens if it's left open to air?
2) will oil spew out?
3) can I simply run some sort of patch hose from the AOS to the J-boot?
4) what's the purpose of the check valve as mentioned above?

Thanks,
Ian

PorscheDoc

You need to run a hose from the OAS to the jboot if you are not running the hose with the check valve. My theory is under hard boost, the valve opens and allows outside air into the system, instead of sucking oil vapor from the crankcase, and causing excessive oil to be introduced to the intake stream. When the boost pressure drops, then it shuts and feeds off the crankcase again.

flyguy

Porsche doc, sounds good, the next question then is does that hose with the check valve actually run all the way to the J boot or is it simply a length of hose with a closed end and the valve? if it does go all the way to the boot, how do you plumb it in with the original male end that was on the hose connecting the original hard pipe to the J-boot?

Thanks,
Ian

PorscheDoc

It is a hose that runs between the J-boot and the OAS. I have not installed this hose yet, and it was the part number I pulled out of PET. The 89 944T that I have at the shop, the hose is cut just past the valve, and that end attaches to the metal hard pipe with a hose clamp. I would guess the other part of the hose attaches to the other end of the metal pipe. Similar to how you have to cut the updated brake booster line to insert the check valve at the firewall. When I go to install it, I will know a little more. PET also shows the line as having a 90 degree elbow coming off the OAS near the valve end, but the part that came from Porsche obviously does not have that 90 degree bend in it, so I will have to play with it a little.

mj951

I replaced my vac lines last winter with a few other things on my '89 turbo.
Yep the valve is stock. Short 90 deg. hose off the AOS with the valve before it tee's into the metal pipe. I ended up leaving the 90 with the valve in and went male to male with a new hose to the J boot, not because i know what i'm doing but because i didn't know what the valve did.
A couple of pics from last years project and one from today.
You can see the valve going off to the left of the 90 deg. hose.

FSAEracer03

It's certainly possible to bypass the CV without removing the intake, but you sure can't do the full venturi delete with it still on. I think that's the confusion. I bypassed the CV last year in my red 951, but since I have the manifold off the silver project car, I'm going to do the delete kit.

I hate the mess under the intake manifold.

PorscheDoc

I have the new hose installed on my engine, which is sitting on the stand. I will pull the intake and take a picture of it all....

daigo

I'd like to see that.

ivai

PorscheDoc, this makes sense to me.. but wouldn't there need to be some sort of filter on the little checkvalve to prevent foreign material from entering the turbo/engine? Are you able to tell if it has such a thing?

-Jeff

PorscheDoc

I haven't looked at the valve that closely, but i would imagine it has some sort of filter paper in it.

billthe3

Any chance you took pictures? I have all this stuff out in the open so I want to do it, if I can figure out exactly what to do.

On somewhat the same note: do you have to buy all the official porsche lines or can you run some tubing in their place? Looks like the one with the valve can't be cheaped out on, but what about the rest? Anything special about the porsche lines?