Last Lemming

While I was replacing my brake booster and master cylinder I also replaced a few hoses under the intake manifold that looked a bit tired. I also replaced the o-ring in the Venturi, it wasn't a perfect match but it did seem to do the job. The two hoses I replaced was the one going to the brake booster and one that came off the Venturi. If I remember correctly the one coming off the Venturi had a metal restrictor in line with the hose. What is this restrictor for? Also what is the point of the Venturi anyway? I know there is a delete for it but I'm trying to keep the car as original as possible.

V2Rocket

if you mean the Y shaped thing the brake booster hose connects to, it's to provide constant vacuum to the brake booster and accessories even if you have the throttle wide open (autobahn conditions) where there would normally not be manifold vacuum.

Last Lemming

No I'm talking about a little metal piece that goes in the vacuum hose itself and has a hole drilled through it it ( about 1/16 of an inch diameter hole) and connects into the Y

Last Lemming

No I'm talking about a little metal piece that goes in the vacuum hose itself and has a hole drilled through it it ( about 1/16 of an inch diameter hole) and connects into the Y

V2Rocket

you mean this one...
https://rennlist.com/forums/924-931-...this-part.html

someone's post that "makes idle go high without it" makes sense to me, as that lower hose bypasses both the throttle and the idle valve so it is probably a "calibrated vacuum leak".

Last Lemming

Ahhh. That's what it's for. Thanks

mel_t_vin

Spencer, is that a 944-only restrictor...or is that also part of the 951 plumbing?

If part of the 951 plumbing, do you have a photo of where it resides?

V2Rocket

never taken apart 951 vacuum-octopus so i can't say for sure.

Last Lemming

Well it came off my 951 and it's pretty much stock

mel_t_vin

Would you happen to have a photo or diagram that shows the location of this restrictor?

Last Lemming

My car is back together so I can't take a picture so take this info with a grain of salt since I'm going from memory, but the plastic "y" Venturi has a rubber vacuum tube coming off the plastic "y" at an angle, on this rubber vacuum hose there is a clamp in the middle of it. That is what tipped me off to look in the hose. I wondered why a clamp would be in the middle of the hose and not on the ends clamping it down. The clamp holds the small metal restrictor inline in the hose.

Tiger03447

Is this restrictor in/on early 944's as well? I'm away from my shop right now...thanks in advance..

V2Rocket

tiger it was on my early na.