diskzero

I have discovered a nightmare of safety wire, bad hoses and clamps and a broken venturi tube under my manifold. The magic restrictor was also missing. I have read several threads where people have removed the venturi and oodles of tubes by utillizing the layout of the 88 and newer models. I have an 86 951 and when I compare the diagram from the PET for an 88 I am amazed at the extra tubing. What is going on here? Did the Porsche engineers determine that the venturi and restrictor are not needed? Is all of this plumbing for the Turbo model only? Has anyone done this conversion with success?

Thanks!

cpt_koolbeenz

Good question. I am wondering this as well.
Anyone know?

TonyG

diskzero

I'll make your life real simple...


You have (2) ports coming off the intake.

Take one, and run it to your brake booster (make sure to leave in the check valve with the "T" fitting that resides close to your firewall).

Take the other, and run it to your intercooler pipe, just before the throttle body.

Throw the rest in the trash.

Ahmet

That does sound simple, except there's room for error w/the "t fitting" thing. There's lots of ts in that area. I for one would appreciate a picture. Also, what then do you do w/the idle air stabilizer, the plastic y, the restrictor, and the metal t connection?
Ahmet

diskzero

Tony,

Woah! No idle stabilizer? I like the brutal simplicity of your solution, but the idle stabilizer must play some role? I take it you have been living without one? Ahmet, it sounds like Tony is saying to dispose of all of the stuff under the intake.

awilson40

heres how you do it. I cant take credit for the drawing but it is spot on.

Jeremy Himsel

Tony's right but I'd use the idle stabalizer if this is something you drive on the street, use AC, start in cold conditions etc... If you call paragon they can sell you the updated hoses that you need. hose 1 is the intercooler tube to the IS inlet connection, hose 2 would be the IS to the intake connection, hose 3 would be the brake powerbooster to intake connection (between runners 2&3). Hose three needs to be cut as Tony suggested to put the T with checkvalve in. A picture of this isn't really needed as there is only one hose coming off the brake power booster so make your cut in the same location. And yeah, throw the rest of the **** out, it'll make you feel better.

dmoffitt

i'm running an idle-air stabilizer but it doesn't seem to be doing much of any good, or maybe my car still needs some drastic tuning (idle = dissapointing). it's not so much AT idle, it's like when i am cruising down to a stoplight, and take my foot off the throttle it has a tendancy to stall (not the end of the world, i remember to blip it a couple of times, or i drop it into 2nd, and release the clutch, and it restarts, but it's kinda embarassing / annoying).

TonyG

diskzero

Sorry guys.... it was late.

Yes you run the idle stablizer (the IAC).

So what I should have said was to go from one port to the brake booster (keeping the check valve and T fitting).

Then from the other port, go to the IAC, then to the intercooler pipe just before the throttle body. Make sure the IAC is conncted in the proper direction. There is an arrow on it which indicates the direction of air flow, and should point towards the intake manifold.


Sorry about that. :-)

TonyG

TonyG

dmoffitt

Are you running the Pro-M? If so, and I think I heard you say you were... it's because you're too rich on your Vin/Vout in the first 3 cells.

Take it down, and you won't drop through idle.

TonyG

Brian Fugok

Are the three hoses needed to simplify this mess special items available from Paragon or just the factory hoses from the 88 and newer models?

Thanks for the details on this, once again simpler is better.

David Floyd

Fewer hoses fewer vacuum leaks.

Also check out the post, "Whats this? Do I need it for the j-pipe"

This is dealing with removing more hoses ( emissions stuff ) some of you guys won't be able to do this

Brian Fugok

David, thanks for the tip. I will keep the gas tank vent/recirculate system for now.

Any ideas on the 3 hoses needed to remove the venturi tube crap? Are they modified hoses from Paragon or factory parts from the 88 and newer models?

Jeremy Himsel

They're factory hoses with 951 PN#'s. A friend of mine called to order the normal replacement hoses and Paragon sent the updated kit (kudos to Paragon). Give them a ring and ask.

Oddjob

The change over is a factory design, done sometime in MY88. Im not sure if it was for the Turbo S only, or if it was a universal change over.

When removing the venturi system and updating to the later style, do you notice any change in brake pedal effort? With the venturi and restrictor removed, is more vacuum draw applied to the brake booster, increasing the power assist?

Ive noticed that my 87 turbo (venturi system) has a harder pedal and brake effort than my 89 T. Im not sure that is related to the intake plumbing or one of a number of other variables. Anyone that has done the upgrade notice any different brake pedal feel?