carbon catchcan- installed(pics)

[gt40]

Finally got the new design done:

http://www.socalevo.net/gallery/albums/gt40/IMG_4349.sized.jpg

http://www.socalevo.net/gallery/albums/gt40/IMG_4350.sized.jpg

http://www.socalevo.net/gallery/albums/gt40/IMG_4351.sized.jpg

Yeah, I know the ss lines are pure unadultrated bling- I had left over material from the fuel system install so...

[GokuSSJ4]

you need more bling bling parts like sam has :P
looks great !! but you need to make a better bracket :?

[Evo-8]

whats the point of the catch can? I mean i know it prevents the oil from splattering all over the engine bay but why not just let it go back into the intake? I would think it helps the turbo by re-oiling it or sumthin. Can someone enlighten me? Don't know much about this.

PS. definitely need a better bracket. That strap just craps on the look of the catch can.

[ReHeat]

The blow by oil would be coated on the inside of the intercooler and decrease the cooling efficiency, a catch can should prevent all those blow by oil from entering the intake system.

[Evo-8]

The blow by oil would be coated on the inside of the intercooler and decrease the cooling efficiency, a catch can should prevent all those blow by oil from entering the intake system.

that doesnt make sense. Why would mitsu make it shoot back into the intake system on purpose if its bad for the car? It just doesnt make sense.
The hose goes straight from the motor to the intake tube. If you change the intake tube then im sure u need a place to put that oil but on the stock intake pipe why would you need to change it?

[Absinthe]

the other issue other than oil coating the the IC is that oil has a low relative octane and will effective lower the octane of the gas you are using if excesive amounts get into the intake.

I am assuming Mitsu didnt include one based on cost and the fact that this issue doesnt much present its self in a street driven stock turbo car.

[Evo-8]

the other issue other than oil coating the the IC is that oil has a low relative octane and will effective lower the octane of the gas you are using if excesive amounts get into the intake.

I am assuming Mitsu didnt include one based on cost and the fact that this issue doesnt much present its self in a street driven stock turbo car.

I don't think it was a cost thing. If it could possibly damage the car, they could have simply had the hose run into a small plastic container as apposed to having it run into the intake tube. There must be a reason for it.

[Absinthe]

like I also said it maybe that its not an issue on street drive stock turbo cars but when you modify the car and put in a turbo the size of my head it becomes more of an issue.

[gt40]

Per Dr. Gray, under certain track conditions, you can dump a large amount of oil into your intake without a catchcan. In addition, you will fill up your fmic with gunk and need to wash it out with a solvent.

[Evo-8]

Per Dr. Gray, under certain track conditions, you can dump a large amount of oil into your intake without a catchcan. In addition, you will fill up your fmic with gunk and need to wash it out with a solvent.

ahhh. That makes more sense. the "under certain track conditions" helped explain it.

[trannb]

that doesnt make sense. Why would mitsu make it shoot back into the intake system on purpose if its bad for the car? It just doesnt make sense.

CARB and auto manufacturers don't normally agree on how to do things. They probably also don't want to rely on users to periodically check their catch can levels and dispose of the oil properly.


The hose goes straight from the motor to the intake tube. If you change the intake tube then im sure u need a place to put that oil but on the stock intake pipe why would you need to change it?

You don't want oil to go back into your intake system. Your intercooler will lose efficiency and it becomes a big mess. Many aftermarket intake pipes have provisions for the oil line. You'll want to cap it off in both scenarios.

[gofaster87]

Technically its better to have vacuum sucking the crankcase pressure into the intake manifold. Makes more of a difference on V8s than 4 bangers. This is why they have a PCV valve on the valve cover, but most people just vent both lines to atmosphere. The vacuum assists in pulling more pressure out.

[jondukes]

wheres mine at mark

[Blak94GSX]

The way Mark set it up looks to be near ideal. As was said, it is good to pull a vacuum on the crankcase if at all possible. The pistons moving up and down inside the crankcase create a pretty large pressure wave. The less air pressure there is behind the pistons during the power stroke, the less power loss. The intake pipe (pre-turbo) sucks in enough air to aid in venting the crankcase when compared to using a catchcan with just a filter on it.

For smog the PCV is required. This is basically a one-way check valve. When the engine is in high vacuum conditions, like off-throttle coastdown or idle, the PCV is sucked open and allows crankcase gases (oily vapor) to flow into the intake manifold, where it is then burned in the combustion chamber and reduces smog. Oil burned with gasoline in the combustion chamber produces less smog than oily vapor vented directly into the air. Also when burned in the engine it goes through the cat as part of the exhaust.

Stock, the car has two breather hoses. One is the PCV which comes off the back of the valve cover and runs directly to the intake manifold plenum. The other is on the side of the valve cover and runs directly to the intake pipe before the turbo. Since the PCV is a vacuum operated check valve, it is closed with boost and as such cuts off a lot of the crankcase breather flow. The side vent is then the only means for reducing crankcase pressure.

The side vent hose which runs directly to the intake pipe can force oil into the intercooler piping and the intercooler core itself. Take the intercooler off of a high-mileage car and I think you will be shocked at how much oil is in there...

By using a catchcan as an oil separator, the PCV is removed and both vent lines are directed into the catchcan, then suction is applied to the catchcan by using a third hose running to the intake pipe (pre-turbo). This allows for more flow from the crankcase with boost, since the PCV is no longer closing off one of the vents, and also the catchcan separates out the oil from the air, so the turbo and intercooler don't get full of goo.

The other method for drawing a vacuum is to put a tube in the downpipe with a backcut on it using Bernoulli's Principle to create suction on the pipe. The intake hose method is easier, although I haven't done proper A/B comparisons to see which actually works better in practice.

[Blak94GSX]

The real proof will be after a couple track days when Mark drains the catchcan... Whatever is in the catchcan is what would normally have been sucked into the turbo/intercooler.

[leaveit2bevo]

wheres mine at mark

thats what im saying

[gt40]

I have 2 more almost done - just have to sand. Jondukes should be ready sat

[Evo-8]

The real proof will be after a couple track days when Mark drains the catchcan... Whatever is in the catchcan is what would normally have been sucked into the turbo/intercooler.

GOD DAMNIT! I love it when Dr. Gray chimes in. Just makes u feel like a genious after taking all that in.

[gofaster87]

Abtin, you really have feelings for scott dont you!!!

[Evo-8]

Abtin, you really have feelings for scott dont you!!!
lol. I just respect the man for knowing so damn much and sharing is knowledge. btw how much do these run for mark?

[Boosted]

nice work man that looks sweet

[gt40]

I have one more done- material cost is going up a tad so it will be $90...

I added some separator stuff so there are tubes running inside to some steel wool to better separate the oil from the air.

Start a list and i might get off my ass :P

-jondukes: yours is ready to be installed- pm me your number if you want to come over and we can hook it up.

[evo808.com]

cant see the pictures

[gofaster87]

cant see the pictures


Probably because the post is a year old.

[lagcisco]

so a catch can is a good idea if you run your engine hard? ie track days?