AOS modification.
#166
gentlemen, I've been pondering this a lot.
Instead of venting to the airbox, how about just installing an electric vacuum pump instead.
So basically, aos> catchcan> electric vac pump.
Accomplishes the same thing, but you have steady vacuum of approximately 10in/hg and no dirty air filters. Might still have fuel trim issues as the pumps vent to the atmosphere, but I'm not sure.
I want to give this a shot.
Instead of venting to the airbox, how about just installing an electric vacuum pump instead.
So basically, aos> catchcan> electric vac pump.
Accomplishes the same thing, but you have steady vacuum of approximately 10in/hg and no dirty air filters. Might still have fuel trim issues as the pumps vent to the atmosphere, but I'm not sure.
I want to give this a shot.
#167
Captain Obvious
Super User
Super User
Joined: Aug 2003
Posts: 22,846
Likes: 340
From: Cambridge, Ontario, Canada
gentlemen, I've been pondering this a lot.
Instead of venting to the airbox, how about just installing an electric vacuum pump instead.
So basically, aos> catchcan> electric vac pump.
Accomplishes the same thing, but you have steady vacuum of approximately 10in/hg and no dirty air filters. Might still have fuel trim issues as the pumps vent to the atmosphere, but I'm not sure.
I want to give this a shot.
Instead of venting to the airbox, how about just installing an electric vacuum pump instead.
So basically, aos> catchcan> electric vac pump.
Accomplishes the same thing, but you have steady vacuum of approximately 10in/hg and no dirty air filters. Might still have fuel trim issues as the pumps vent to the atmosphere, but I'm not sure.
I want to give this a shot.
#169
Been reading thru this thread and I'm surprised no one seams concerned about where the AOS 'catch' ends up. Yes, dirty oil/fuel/water mix is being put back in the sump to lubricant your engine. It's a closed system and all the blow-by product is re-introduced in the engine oil.
My AOS also needs replacing and I want to replace the AOS completely with a industrial catch can(google MANN ProVent) where the 'catch' is being accumulated in some kind of container and will need emptying from time to time.
There is two things with the current AOS system I haven't figured out which I would need some help with. Look at the picture below. There are two thin lines going to the AOS, item 13 and 12. Can someone tell me where they are connected? And maybe their purpose?
My AOS also needs replacing and I want to replace the AOS completely with a industrial catch can(google MANN ProVent) where the 'catch' is being accumulated in some kind of container and will need emptying from time to time.
There is two things with the current AOS system I haven't figured out which I would need some help with. Look at the picture below. There are two thin lines going to the AOS, item 13 and 12. Can someone tell me where they are connected? And maybe their purpose?
#171
Thank you! Now when you write it I remember reading it was coolant heated. I was afraid it was a balanced pressure equilibrium system, that would have been tricky to replace.
Ok, so I will build a system to replace the AOS with a catch can. I have a build thread and I will put all the details there: https://rennlist.com/forums/996-foru...ew-life-3.html
Ok, so I will build a system to replace the AOS with a catch can. I have a build thread and I will put all the details there: https://rennlist.com/forums/996-foru...ew-life-3.html
#172
Mann Provent
The Mann Provent has been discussed previously.
See Schnell Gelb 04-19-2019.https://rennlist.com/forums/928-foru...ation-kit.html
It has also been discussed on the 928 Section of this Forum.https://rennlist.com/forums/928-foru...ation-kit.html
The Mann Provent does not seem to solve the problem of controlling the vacuum. It seems like this would be a simple problem to resolve until you read how many smart enthusiasts and vendors have failed. Which just makes the 'prize' for success even greater :-) It is a worthy technical challenge .and many of us would be most grateful for a solution. Good Luck.
See Schnell Gelb 04-19-2019.https://rennlist.com/forums/928-foru...ation-kit.html
It has also been discussed on the 928 Section of this Forum.https://rennlist.com/forums/928-foru...ation-kit.html
The Mann Provent does not seem to solve the problem of controlling the vacuum. It seems like this would be a simple problem to resolve until you read how many smart enthusiasts and vendors have failed. Which just makes the 'prize' for success even greater :-) It is a worthy technical challenge .and many of us would be most grateful for a solution. Good Luck.
Been reading thru this thread and I'm surprised no one seams concerned about where the AOS 'catch' ends up. Yes, dirty oil/fuel/water mix is being put back in the sump to lubricant your engine. It's a closed system and all the blow-by product is re-introduced in the engine oil.
My AOS also needs replacing and I want to replace the AOS completely with a industrial catch can(google MANN ProVent) where the 'catch' is being accumulated in some kind of container and will need emptying from time to time.
There is two things with the current AOS system I haven't figured out which I would need some help with. Look at the picture below. There are two thin lines going to the AOS, item 13 and 12. Can someone tell me where they are connected? And maybe their purpose?
My AOS also needs replacing and I want to replace the AOS completely with a industrial catch can(google MANN ProVent) where the 'catch' is being accumulated in some kind of container and will need emptying from time to time.
There is two things with the current AOS system I haven't figured out which I would need some help with. Look at the picture below. There are two thin lines going to the AOS, item 13 and 12. Can someone tell me where they are connected? And maybe their purpose?
#173
Captain Obvious
Super User
Super User
Joined: Aug 2003
Posts: 22,846
Likes: 340
From: Cambridge, Ontario, Canada
Thank you! Now when you write it I remember reading it was coolant heated. I was afraid it was a balanced pressure equilibrium system, that would have been tricky to replace.
Ok, so I will build a system to replace the AOS with a catch can. I have a build thread and I will put all the details there: https://rennlist.com/forums/996-foru...ew-life-3.html
Ok, so I will build a system to replace the AOS with a catch can. I have a build thread and I will put all the details there: https://rennlist.com/forums/996-foru...ew-life-3.html
Why are you trying to reinvent the wheel. Just use the stock unit and be done with it. It works well.
#174
This is not re-inventing the wheel. It makes the following improvement (as mention on the top of my build thread I’m re-engineering some of the bad solutions on the car):
+No risk of hydrolock in case the AOS break
+Cleaner air gets re-circulated (less oil in it)
+No bad oil re-circulation in the engine
+Easier to service
On the negative
-More labour, one more filter(every 40000km) to change and oil(5000km) to empty on regular times
-Not original (but for me that is not important)
And then we have the discussion of engine problems with the M96 engine. Having bad oil to lubricate the internals doesn’t help. And using it as an oil-burner also doesn't help.
For me this is the perfect solution as the oil in the engine is kept as clean as possible.
+No risk of hydrolock in case the AOS break
+Cleaner air gets re-circulated (less oil in it)
+No bad oil re-circulation in the engine
+Easier to service
On the negative
-More labour, one more filter(every 40000km) to change and oil(5000km) to empty on regular times
-Not original (but for me that is not important)
And then we have the discussion of engine problems with the M96 engine. Having bad oil to lubricate the internals doesn’t help. And using it as an oil-burner also doesn't help.
For me this is the perfect solution as the oil in the engine is kept as clean as possible.
#176
Before we start a new attempt to improve the AOS it seems prudent to carefully review why previous attempts by all others failed. Most were much smarter engineers than me no doubt, Some are pros from the Porsche aftermarket.They all failed to improve(commercially) on the original AOS (except the Motorsport alternative). Why ? We couldn't find a better way to regulate the vacuum within the limits required for M96. That is way more important an obstacle than the 'dirty oil' problem. Just change the oil plus filter more often if that is the concern? And avoid 'swamping' the AOS with excess oil or wild turns?
It would be wonderful if someone could improve on the AOS system but lets not spin any reinvented wheels. We've done lots of that already and documented it for all to read.
It would be wonderful if someone could improve on the AOS system but lets not spin any reinvented wheels. We've done lots of that already and documented it for all to read.
#177
I spent a lot of time reading all things AOS/Catch can and came to the same conclusion...Just replace with a new Porsche unit, monitor (manometer) and drive with clean oil changed at 3000k or six months!!
#179
It would be nice to have an alternative to removing the engine to replace a cheap plastic part. I have read a DIY that demonstrated that it can be done without engine removal, but it looked like quite a bit of pain and heartache might be included in using that method.