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ljd931 · Joined: 16 Dec 2002 Posts: 49 Location: Tallahassee, FL

anyone else done this modification? you can find it on this 931 webpage:

http://medlem.spray.se/p931

very interesting . . . please share any info you might have concerning this modification.
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ljamesdickinson@yahoo.com
parting out - '81 931
looking for - '88 924S w/ m030 & LSD

924RACR · Posted: Tue Dec 24, 2002 1:30 pm Post subject:

I've got it on my racecar... the oil vapors cut down the effective octane rating of your fuel, IIRC... so you make less power. But it's seriously non-EPA-approved... releasing all those hydrocarbons to the atmosphere...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Peter_in_AU · Joined: 29 Jul 2001 Posts: 2743 Location: Sydney, Australia

actually depends on the type of separator / catch can you use.

The competition style ones just vent to atmosphere but if you have to pass pollution tests you can buy/make a can that vents the "cleaned" air into the intake via a one-way valve and returns the oil to the sump also via a one-way valve. If the scrubber design is good it should remove most of the oil and crud from the air.

Closed-circuit catch cans are fitted on some new cars. I think HSV who sell modified Holdens down here fit them on their new cars.
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1979 924 (Gone to a better place)
1974 Lotus 7 S4 "Big Valve" Twin-cam (waiting)
1982 924 (As featured on Wikipedia)

Learn to love your multimeter and may the search be with you

924RACR · Posted: Tue Dec 24, 2002 10:48 pm Post subject:

Mmmmm... HSV.... yummy...

We have a Commodore hanging out here in the garage... was really blown away by the quality, appeareance, feel, etc. of it... really makes everything else coming out of Detroit look like garbage (as it pretty much is)... seats 4 comfortably, even in the back, 6-speed, RWD, V8, and all the goodies... nothing else comes close. My crew chief, who has a Trans-Am (a relatively new one) said he'd sell it to get one of these. He's also a major Pontiac dude...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Peter · Joined: 04 Nov 2002 Posts: 379 Location: New York, NY

The 931 has the "check valve" type described by Peter-in-AU. If I recall correctly, it is made by Purulator. It is a small plastic can with three hose connections on it: top attaches to breather valve on block and takes in air/oil vapor, bottom directs oil to pan and other top directs "cleaned" air to air filter.
The "mod" you asked about was because the guy is not using the stock air cleaner, and if he did not put a plastic soda bottle to catch the air/oil, it would dirty up his engine. You could run a long hose under your car and vent there; however, it is bad for the environment. As for more HP, you will not notice a difference.

Peter_in_AU · Joined: 29 Jul 2001 Posts: 2743 Location: Sydney, Australia

they have an indirect effect on hp. Without a catch can the oil vapour and crud going into the intake reduces the octane rating of the fuel meaning you have to run less advance to avoid knocking.

Good to hear that the HSVs are go down well over there. They do seem to do a good job of taking a very ordinary family car and turning it into something a bit more lively.
_________________
1979 924 (Gone to a better place)
1974 Lotus 7 S4 "Big Valve" Twin-cam (waiting)
1982 924 (As featured on Wikipedia)

Learn to love your multimeter and may the search be with you