Hi all,

We've installed a G50/21 from a 993 into my 964 project car, and I had a question about the clutch cooling vent (no idea if this is even the correct term for this thing). The photos are below, but basically the vent pipes in from somewhere, and circulates air through the clutch area, and then vents out into the airbox.

My question is whether or not any 993 owners have done anything to modify this vent? I don't have the correct piping so we're tossing some ideas around as to what to do with the vent since it's there as opposed to just blocking it off (the 964s don't have this vent system, so blocking it off will not have any detrimental effect).

Thanks in advance for any input!

 

If I'm not mistaken that's the vent tube that meets up with the air box. This post here https://rennlist.com/forums/993-foru...e-it-with.html talks about removing the tube and mentions a plug that goes on the airbox side. I'd bet someone with a PET digram and see if there's a matching plug on the other side.

 

Thanks for the link, much appreciated!

PET shows the "intake manifold" part number as 993 116 061 00. Would you (or anyone else reading this) happen to know where this leads in from?

I figure I can follow the tips on the other thread to leave a breather pipe for the exhaust port, as long as there is positive pressure from where it originates. In other words, whether the air circulation depends on positive pressure from the intake side, or suction from the exhaust side (which is why it was originally designed to exit out into the airbox).

 

The 'intake' side uses an upturned plastic elbow to allow air in, while the 'exhuast' side has a plastic adaptor that mates with a black cloth-like pipe. I presume that a running engine will always impart a slight vacuum on this hose.

Some people have simply disconnected the 'exhaust' hose and allowed the bellhousing to vent to atmosphere.


Andreas

 

Roadsleeper,

I would recommend that you mount the attachement elbow and make some sort of vent tube that attaches to the air cleaner to allow the clutch dust to vent. I know a lot of people complaint of the air filter gets dirty quickly from the clutch dust and decides to remove this "feature". I believe this is a good feature on the 993 transmission as it allows the clutch dust material to vent out of the housing, as I have seen plenty of clutch dust build up in that area which causes "not to good" operation of the clutch fork and throwout bearing. Which causes rough clutch operation.

See how filthy it gets? Before & after cleaning. The vent tube on this transmission was not attached properly.

 

Robin 993DX - You could eat off of that gearbox in the "after" pic!!

Unfortunately (or fortunately, IMHO) I run individual throttle bodies so there's nowhere for the pipe to exit out to.

Now that I know that the system is reliant on suction from the airbox/engine (thanks AOW162435!), it looks like I will have to either a) figure out some way to design ducting to scoop air (and more importantly no external junk) into the bell housing, or b) just cap the ventilation ports off...

Thanks for the input guys!