TurboTommy

It's an '87 car with the venturis under the intake manifold.
There is a restrictor in one of the hoses coming from/to the idle stabilizer (little bit of a fuzzy pic, but the end of the flat head screwdriver is pointing to the spot where the factory threw on a clamp; I guess to hold the restrictor in place, in the hose)
What's this air restrictor for?
I'm planning on doing venturi delete and then, I guess, I'll be getting rid of this restrictor as well.

JohnKoaWood

The venturi delete will get rid of it... 1 hose from intake to brake booster, 1 from intake to ISV, 1 from ISV to j boot...

TurboTommy

Yeah, I know the venturi delete will get rid of it.
My question is; why did the factory put that restrictor in there?
Does anybody know?

TurboTommy

Bump;

you mean the rennlist community is stumped with this one?
There must be a reason the factory put that restrictor in there.
Maybe to save the idle stabilizer against suddenly closing the throttle?

The DareDevil

Photos from billthe3's thread: https://rennlist.com/forums/944-turb...te-thread.html

TurboTommy

Yeah, that's the one
Thanks for the better pic

gcb951

This is actually a picture of your flux capacitor, which if my calculations are correct, should make time travel possible. All you will need is 1.21 jiga watts and 88mph.

Not so funny? Here is the diagrams to do the delete.

http://www.lindseyracing.com/LR/Parts/VACDIA.html

TurboTommy

The original poster of this thread is probably wondering why people keep posting that the venturi delete will get rid of the restrictor.
It's quite clear that he just wants to know why Porsche installed that restrictor in the original air hose routing (it might be there for some sort of semi-important reason).

kinglenario

yeah, i notice that with the venturi delete and once i removed this restrictor the idle will drop to about 700rpm for a split second before it comes back up. i bet that's what the restrictor is for. there is probably too much vacuum going straight to the idle stabilizer, or to use more vacuum to the brake booster than to the idle stabilizer. either way my car ran more smoothly without the lindsey venturi delete. i might be going back to factory venturi setup the next time i have to take the intake off.

Bri Bro

You need to adjust your idle before you jump back to the venturi. It sounds like it is set too low and the idle controller is having to bring it up. Clarks garage has the procedure.
http://clarks-garage.com/shop-manual/fuel-08.htm

Scott H

This, set the idle on the high end of the scale, ~900rpm, especially if you use your A/C. You're aiming for a needle-width below the 1k RPM line. Make sure the oil is up to temp before adjusting the idle, if you adjust while the car is still cold the idle will still be off.