Not an instructional thread but one that may interest those who are planning to remove their N249, SAI, PCV, Vac Res. and install a Catch Can.
This week I started by ripping out all the many redundancies that are in the 1.8t's design. ((NOTE) If you remove redundancies such as the one that goes to the brake booster make sure you inspect these vacuum lines regularly))
I also turned my throttle body so that the butterfly opens toward the front of the manifold. Not only does this look better, but many people claim you get a more even flow to all 4 cylinders. I cannot say this is true or not, but I do notice a much smoother acceleration after rotating the TB.
I removed almost every redundancy I could find. there are still a few I need to work out. ( there is a great DIY for removing the N249, SAI etc. ) Most people, me included do this to make their engine bay cleaner, it also makes it easier to find a problem if you have a leak. (ie. direct line to brake booster, you slam into a wall you know your vac line to the booster is gone ). Another plus of doing this besides the ridiculous amount of tubing, check valves and crappy plastic tubes that snap if you look at them wrong, is that you will have several direct vacuum ports to use for your Diverter or BOV, Boost Gauge, Boost Controller or any other component that needs a Vacuum line.
Having a direct vacuum line for the diverter valve makes the response alot quicker and depending on how you are running, if you spike higher than your car likes you will normally hear the diverter open and pssshhttt Boost GONE! Well, with the N249 removed or bypassed this wont happen again. ( this wont by any means prevent limp mode it will just keep the ecu from opening the diverter when it gets scared ). By changing the boost gauge in my car from a tee in the fuel regulator to a direct route on my manifold I have noticed better response to boost levels and a more accurate reading. ( the change is nominal, I noticed a difference you may not ).
For the fun part, at least I think so. The catch can install, there is another DIY for a catch can installation that is great, easy to understand and illustrated.
For my catch can I refused to buy a $100-$300 aluminum container to hold engine gunk. Therefore I decided to make my own. I ended up using an empty bottle of seafoam ( it's thin metal ) some heater hose a breather filter, steel wool and a couple brass fittings. Cost me nothing as I already had the pieces, but this is what they did cost ( used seafoam to find manifold / turbo leak $10 , Brass barbs $3 , Breather filter $8 , hose clamps $5, heater hose $8 ) I'm not going to describe how to make one or install, as there are many DIY's already explaining how to make and install a catch can. Point is it's easy, there are many things thou can use if you want a certain shape or size, etc. It cost me around $30 if I had to buy the parts, and if you buy something like seafoam you can use it in the car, duh, and recycle the can to your project.
If you don't understand the point in removing the PCV system for a catch can remove your intercooler and check out what's inside, ( Hint, it's OIL and usually between a shot glass full and a cup full ) Obviously we don't want those things going through our intake system and gumming up the IC pipes, IC, Throttle Body, Intake Air Temp sensor (IAT), MAP sensor and possibly reaching your injectors, valves etc. The other problem with this system is the "Hockey Puck" on the turbo inlet this is the PCV vent valve, this is where all of these contaminates enter your intake system. You notice this is before the compressor. It may just be me but I don't even want oil vapor hitting the fins if the turbo and turning to varnish. It's just extra weight on the fins which "could" haven't seen it but theoretically it's possible that they could get out of balance and cause excessive vibrations,etc.
When removing the PCV system I found that almost every hard pipe was cracked or broken. The PCV was venting on my transmission. I'm sure if you check yours you will find some that have failed or are close to failing. One of the most common being the Y pipe from the valve cover vent needs replacing all the time.
Summary of all that I have explained is that if you are so mechanically inclined it takes some time but it's easy to remove the redundant vac lines. Having direct Vac lines looks cleaner and makes problems easier to diagnose. By removing the PCV system and replacing with a catch can you get gid of A LOT of pipe and you keep your intake clean, not to mention engine bay if one of these pipes should break, and they will. Having a direct line to your DV makes it more responsive and the ecu cant open it on command. Finally, by turning the throttle body so that the butterfly opens toward the front of the car it not only cleans up the bay but seems to smooth out the acceleration. All in all I would say I am very happy with the new setup and I'm sure you will be too if you do the same.
I will have some pics of the aftermath and results soon.