944CS

nope no harm at all, you might actually gain a horsepower or two and it will help prevent oil leaks as well

DDP

Drilling the AOS opens it up how much? Hardly anything. And the AOS must be removed to drill it out. It's not necessary, no matter your power output.

And if you want to argue on the side of ridiculous, you can say that at a higher output level you're moving more air and therefore pulling more vacuum.

DDP

Do you think the added 1/8" in diameter is going to act as a dry sump? Come on guys, let's not get carried away here.

CP944T

Thanks, sounds like it will help, just a pain to do if removing the canister entirely to drill it vs. melting it open as some have done.

944CS

if it were a dry sump, you could dictate whatever pressure differential you wanted and the gain would be more than 1 or 2hp.

why not try and maximize efficiency wherever you can?

DDP

I agree with maximizing where you can, although within reason. Not every car is a race car. If the AOS isn't out it's just not worth the work to remove it and drill, just for the single purpose of more crankcase vacuum. And even so, if the AOS was out and one were to drill it, the increase, if there were any, would be unmeasurable.

DDP

Re-reading my reply I just now realized how silly of an argument this is, lol. Good luck with what you choose, Kyle.

Jay Wellwood

Resurrecting an older thread regarding the use of a catch can and enlarging the AOS opening.