What size hoses do we need to use with a catchcan for the STi?

For which sytem? PCV or valve cover breather?

Bikerboy

For both. I was thinking of running 2 catch cans. Is that a good idea?

the hoses on the valve covers are to let fresh air into the engine. the one coming from the block with the sensor on it is for the blowby gases to get out

Originally posted by ej25lvr
the hoses on the valve covers are to let fresh air into the engine. the one coming from the block with the sensor on it is for the blowby gases to get out


ej25lvr:

The valve cover vents are just that vents. If that hose enters the inlet tract before the turbo how would air enter the heads? It can't since the intake runs into a vacuum, Correct?

To further support my point, why would oil make it all the way from the heads through all the lines to the intake and I/C? People have had this problem including me.

Your second point is correct except the "sensor" is just a bridge. If you pull the conector and disconnect the sensor from the intake you can look at it better and see that it is just jumped to the other wire. Don't know why it is there, maybe a kind of idoit light if you forget to plug the wire in it gives you a code so you can find the pipe off the intake?


No flames just the facts.

imminence:

Yes, you would want to do both IMHO to separate bottles then back to there respective inlets in the intake.

Matt

no flames. i just looked in my pdf files for the sti service manual under crankcase emission control and it says in a part throttle condition,the blow-by gas in the crankcase flows into the intake manifold through the connecting hose of crankcase and pcv valve by the strong vacuum created in the intake manifold. under this condition, fresh air is introduced into the crankcase through the connecting hoses on the rocker covers. id put it on here for everyone to see cause it has a pic of the direction of flow and all but i dunno how to put it up here. if someone could tell me how id be glad to. according to the manual i have my catch can installed wrong cause i have my rocker covers and pcv tee'd into each other. i might redo mine still trying to figure another aspect out as there is also another hose that goes under the throttle body and basicly connects the cover to each other kinda like the one mounted on the intercooler but without the route to the intake. it doesnt show this part at all in the service manual. ill keep checkin lol

Originally posted by ej25lvr
no flames. i just looked in my pdf files for the sti service manual under crankcase emission control and it says in a part throttle condition,the blow-by gas in the crankcase flows into the intake manifold through the connecting hose of crankcase and pcv valve by the strong vacuum created in the intake manifold. under this condition,

correct this is intake to crankcase and plentum

Originally posted by ej25lvr
fresh air is introduced into the crankcase through the connecting hoses on the rocker covers.

Correct: this is the large hoses on the heads that are run together through a tube that runs across the top of the block and dumps into the crankcase. A separate entry to the PCV system



Where our miss understanding is: in the above post I talk about the second vents from the heads that plumb into the tubes bolted to the I/C and then to the intake

You should put a bottle inline on the hose from the PCV to the plentum.

And you should run a bottle inline for the hose from the intake to the piping bolted to the I/C.



Hey you could do me a really huge favor and email me any pdf's you have for the fuel pump controler and the fuel pump relay. I really need this stuff as I am in the middle of a project and need to go through the fuel pump relay and that damn controler :mad:
You would be the man if you could help me out!

:D to moshaff@qwest.com

Matt

ahhh i see what u r saying now cool cool

Thanks for all the great info guys. Now all I need to do is get 2 catch cans and pick my lazy self up to install them. :p

imminence:


I would just make them yourself. Go to the home depot get 2" pcv a couple of threaded couplers and some caps and some barb fittings and you can make one for under 10.00 each

M