Aos

[bbiela]

I just did my first DE in my 2001 986S with 65k miles with Michelin PS4's. First session went fine, then on the second I started to get white smoke on one of the turns, eventually, I was black flagged. Mechanic on site diagnosed it as the AOS. I primarily do autocross and am planning on doing a few DE's every year.

Is the standard AOS sufficient or should I bite the bullet and get the motorsport model?

[Anker]

The AOS was failing before the DE. The stock AOS is fine. The white smoke came because your intake had pooled oil in it and the centrifugal forces caused it to splash into the cylinders.

[KRAM36]

Well if you have $700 burning a whole in your pocket, go for it. You have to do mods to make it work.

[mgfranz]

Or just run it half a quart low from the start.

[thstone]

The problem with the motorsports AOS is cost ($742 from Pelican) plus the modifications that are required to install it. With the stock AOS selling for $80 - $120, its cheaper to just replace them as often as needed.

I replace the AOS yearly as a maintenance item to avoid any problems on the track.

[thstone]

For reference, here is a link to a page that describes the mod's required to install the Motorsports AOS:

Porsche MotorSports Oil Separator - Articles