I have an 02 C5 with an STS twin turbo set up running 12lbs of boost on the high end. I am experiencing high crank case pressure because of the boost and am going to install a "catch can" or K&N filter on my pcv outlet. My question is this, has anyone else done this and is the stock hole large enough to vent properly or do I need to enlarge it? The guy's at STS say just adding a filter to it is enough but I am curious to see what others think.

It's a 5 min job to just add the filter but if I need to enlarge the hole it becomes a much bigger job with some delicate welding involved.

 

Exactly what hole are you referring to?

Running a breather filter off the oil filler cap is pretty "open" and should breath easily IMO.

Never heard of a filter setup on the "PCV outlet" as you called it.

 

:
Iam seriously doing the same thing! Let me guess you are puking oil out of the sts pvc system all over under the hood and hitting the manifold? I just started solving all of the sts problems last night. 1st I installed one of those breathers on the oil fill cap and returned the oil line into the valve cover. 2nd I installed a catch can off of the valve cover vent line the one you are putting a filter on, only I ran it to the catch can, installed a cap on the tb port and then in stalle another breather ontop of the catch can as sts told me that it would be better to run two breather locations, I have no idea how any of this will work yet but I am in the process. 3rd I am gutting the converters painting, wrapping, and sealing the entire exhuast all the way to the chargers, 4th I am putting the scavenger pump in the back of the car right next to the turbos as it is the beter location, just ask sts and this is how they do it on their updated c6 version.

 

Right on someone with the same system. They told me just to unhook the vent line and put a filter on it and that would be enough. And yes it was puking oil out the pvc system and dripping on the manifold, not only that but it would puff blue out the back everytime I got out of boost because of the high crankcase pressure. If it doesnt work good enough I will either enlarge the hole or vent the oil cap and reroute the oil return line.

 

No rocket science here. ECS sells a nice breather to replace your oil cap.

 

I added a K&N filter to my RHS valve cover vent and am testing it to see if that is enough. The tech's at STS say it is so we'll see. As for venting the oil cap, my oil return line for my turbo's dumps into the top of the stock cap so adding a filter is more of a chore as I would then have to relocate the oil return line. That would require drilling and tapping a new hole in the valve cover so I am gonna try this out first and see what happens. Again thanx for all the input.

 

Don't be surprised if you end up with a mess. Trying to force all that crankcase pressure under boost through the 3/8 i.d. hoses in the factory system....

I'm not familiar with the STS oil return, is there a check valve installed in the oil return line?

 

Are you running 12 lbs through the stock bottom end? Are you using meth? Ive got the STS setup with GT32s and I only push 7 lbs right now...Im running it over to the shop tomorrow to do heads/cam/underdrive pulley and dyno tune and looking to up my boost to 9....maybe 10. Ive got the catch can on mine but I would need to see how it holds up to more boost and let you know if it works for me.

 

FYI I already did that and it still made a mess. I am only running 8 psi.

 

Ya it still makes a mess so I'm going with a catch can so it will catch all the oil instead of spraying it all over the engine. I run 12lbs of boost with meth injection and the engine is bone stock save for a short throw shifter and a racing clutch. Insane power and is still in the "safe" zone for these engines. Anyone with this system I encourage you to add meth. It add's some safety to the engine and the power gains are incredible. It is like night and day, after I added meth it felt like going from a non turbo car to a turbo car there was that much of a difference.

I drove around with 7lbs of boost for 6 months and though the car was fast, but after adding the meth it was insane. I'm adding wider tires in the back cuz I can break free in 3rd gear at 90mph now. Trust me, the gains from the meth far excede the cost and you will not be disappointed.

 

I do have the ECS meth kit and once I get my car back from Pavlock I will go ahead and install it. Im thinking I will stick to 10 lbs and play right in the middle of the so called safe zone..LOL. Man I wish you were local cuz I would love to ride in yours with that much boost.

 

I don't know if you bought they're meth kit or not but I did and you can add or subtract boost by turning up or down your meth. I believe it's 2 1/2 turns equal 1lb of boost. I know 12lbs seems like a lot and it probably is but they have numerous vehicles running that boost for years and years with no problems. Nothing is guaranteed but I am on year 2 and the only problems I've had is this crankcase pressure one and the solinoid for the oil pump losing a connection. Both are very easy and cheap to fix so so far I can't complain.

Plus being in Canada I run 94 octane every day. Maybe you do too but I've heard it's hard to come by. Back on topic, I just installed my catch can, which was a lot harder to find a spot to mount it than I thought. I ended up mounting it to my intercooler and running a line down and out to the front dam where I can access the drain **** easily. It's all hidden away so it doesn't look ghetto. Taking it on a road trip next week so will post how it held up as the town I'm going to always finds me racing the local hero's. So far I'm 8 and 0 so here's to my undefeated streak.