Carpokes

I was getting a lot of crankcase pressure in my car, from high boost, so I drilled the top hole on mine and it fixed that problem. I added a catch can at the same time but eventually pulled it out because the bigger hole somehow reduced the amount of oil in the intake track. I don't really have a good answer for you, but on a stock, non-turbo car I would probably leave the AOS alone and start by fixing up the car to run as porsche intended.

Tom wrote: Sat Apr 19, 2025 6:48 am I was getting a lot of crankcase pressure in my car, from high boost, so I drilled the top hole on mine and it fixed that problem. I added a catch can at the same time but eventually pulled it out because the bigger hole somehow reduced the amount of oil in the intake track. I don't really have a good answer for you, but on a stock, non-turbo car I would probably leave the AOS alone and start by fixing up the car to run as porsche intended.

Fair enough. Getting it all fixed up and running as Porsche intended is the goal. Just didn't want to miss an "upgrade" opportunity while I'm in there.

On my track car I put dual -12 bungs on the valve cover to deal with pressure and made a custom catch can to deal with it. That engine routinely sees 25psi boost and is intentionally built a little loose.

Maybe down the road I'll boost this one, but not likely. I want to enjoy it as it was meant to be. I can't wait!

Man, I am struggling with the vac line kit from 944online. All of my hoses under the intake were one step from dust or just gone so I don't have a good reference. If work would quit kicking my tail that would be nice too. The glory and curse of being a good at your job

Time to hit YouTube and Clark's.

PSU_Crash wrote: Tue Apr 22, 2025 6:14 pm Man, I am struggling with the vac line kit from 944online. All of my hoses under the intake were one step from dust or just gone so I don't have a good reference. If work would quit kicking my tail that would be nice too. The glory and curse of being a good at your job

Time to hit YouTube and Clark's.

Check out the diagrams on Lindsey Racing too -- they are pretty much the to-go vacuum routing guides.

https://www.lindseyracing.com/LR/Parts/VACDIA.html

Edit: they are for the turbo though and I just remembered you are working on an n/a

Tom, I was looking at those last night and a little confused before I realized it was for a turbo.

Stoneguy, Thanks!!

My Thermovalve is broke. Any reason not to just skip over it and connect the vacuum valve straight to the intake? Seems to only vent when it's hot and pulling vaccum. Constant vent when running should be fine, right?

I see a lot of talk about the venturi delete. Mine is all cleaned up and re-sealed, so I planned to re-use it. Reading over on rennlist guys say it's not necessary. Thoughts? It's an odd setup for sure.
The big line off the top intake side of the timing cover also seems strange...

Thermovalve removal might cause cold start problems as it will lean out the normally enriched mixture. Also, I can't imagine Porsche adding cost (the venturi) if it was unnecessary to meet a performance, emissions, or safety target.

944er wrote: Wed Apr 23, 2025 8:10 am Thermovalve removal might cause cold start problems as it will lean out the normally enriched mixture. Also, I can't imagine Porsche adding cost (the venturi) if it was unnecessary to meet a performance, emissions, or safety target.

The Venturi is not on the later turbos - I used the 944online Venturi delete and everything seems ok initially.

944er wrote: Wed Apr 23, 2025 8:10 am Thermovalve removal might cause cold start problems as it will lean out the normally enriched mixture. Also, I can't imagine Porsche adding cost (the venturi) if it was unnecessary to meet a performance, emissions, or safety target.

At least on the turbo, the factory ended up deleting the Venturi in the later years, effectively starting the Venturi-delete trend. I removed it from my turbo and have never noticed a difference, and my CA smog test numbers tend to be freakishly low. Folklore says the Venturi was added to generate a modicum of vacuum for the HVAC system during open throttle driving, although the vacuum reservoir would seem capable of that, so I dunno. Can't say I've ever tried turning on the A/C during a WOT pull. No experience with the n/a Venturi delete though...

Fun fact, the Venturi was coined after the Italian physicist who discovered the Venturi Effect, Giovanni Battista Venturi

Personally, I'd keep the thermo valve. Probably won't move the needle either way, but they don't cost much so not sure I'd add another variable into the mix.

944er I figure they did it for a reason too, but then like Tom said, it didn't exist in later years. By the way you have a new subscriber. Excellent videos! I have the venturi cleaned up and ready to reinstall so I'll use it for now at least. I just happened to have the correct plug for the thermovalve already. So that's bypassed. Mostly because I'm impatient and want to get this back in running form ASAP
Whalenlg thanks for the input! It will probably deleted in the future.