SQLGuy

I was looking at Autoatlanta's IPB, and noticed that they illustrate two different kinds of intake (suction) hoses for 87-91, but they only have information about the one piece one. Anyone know anything about this other type of hose (items 12-15)?

http://www.autoatlanta.com/porsche-p...-91/106-00.php

Hilton

Its a sand separator - an option used in some countries (middle east mostly, altho' my memory says that some Aussie cars had it too).

17prospective buyer

Wow, that's pretty neat. They really did think of everything when they were engineering these cars didn't they.

Rob Edwards

There were 323 cars sold in Saudi Arabia (country code 31) and Arab Gulf States (country code 32). Can't imagine there are too many sets of those tubes lying around.

PHIL928

the down side of those cars is that they never had an oxygen sensor... apparently the fuel back in the 80's and 90's in the ME was really low quality, so an oxygen sensor became obsolete?
I'm busy buying a GTS and there is some weird stuff on there.
I'll post a thread with some pictures as soon as I have the car in my possession SOON!

pcar928fan

Looking forward to pics Phil...

bradartigue

Low quality fuel will destroy oxygen sensors as fast as you can change them out, so there isn't much of a point to the fine tuning they provide to an ECU. Similar to the motors Land Rover was making for desert use, they lacked several optimization sensors for the fuel injection system because they would continuously detect normal things - like knocks - caused by crap fuel.

GlenL

Maybe they still had leaded gas. Same effect.

17prospective buyer

They probably did have leaded gas because the vehicles there were probably running a super low CR of like 6 or 7:1. Believe it or not, the world average compression ratio of roadgoing cars today is 6.6:1.

SQLGuy

Cool! Thanks for the info. Always more to learn about these great cars.

Dave928S

Hilton is correct ... they were fitted on my GTS ... but I've taken them off because they're quite restrictive ... and they are total overkill and don't do a thing in normal road conditions. I wouldn't want to drive my car in conditions where they might be useful (sandstorm?) .... and who would intentionally drive their car in conditions where it might get sandblasted anyway?

These have been referred to a few times before, so I thought it was about time everyone can see exactly what they are, and how they work.

I'm attaching a few pics which are self explanatory, and have also done a diagram, because it's not immediately obvious from the outside how it works, and its made up of a few parts.

From the normal inlet points at the front of the car, the air comes in through an aluminium front tube, which is connected to the sand separator with a rubber sleeve, as you can see in the first pic.

Dave928S

Here's a cross sectional drawing showing internal detail and some dimensions.

When it goes into the front of the separator it firstly runs through a 75mm long vortex generator, which throws any heavier gritty particles to the outside of the tube.

After it exits the vortex generator (a further 75mm), there is an inner tube which creates an annular space which traps the grit, which is swirling around.

At the bottom of that annular space is a small outlet which allows the grit to drop into a non return nozzle, which will allow any grit to drop out when there is no suction after the engine is turned off.

PHIL928

Can you buy just the rubber nozzle? I don't see it listed as a separate part.

Dave928S

I assume you mean the rubber non return nozzle.

I can't see a part number on mine but, if you can still get them Roger (928'sRus) should be able to track them down.

If you want me to post some more detailed pics here, let me know.

Edit: It wouldn't be difficult to make an alternative replacement part to do the job.