Catch can opinions

[SFRacingGST]

Recently I have been reading about how to run your catch can. Right now I have a RRE catch can with a breather routed to my PCV valve and my VC breather. However when I drive around with all the windows open you can smell that nasty odor coming from the breather. I trying to make it more like the stock setup, however when I bought my magnus I though a catch can would compliment it nicely.

What I am wondering is where is that smell coming from? The PCV, VC Vent, or both?

Why don’t more people run a line from the vent to the air intake like stock? Is that what causes the nasty build up in the IC piping? How can I route my system so that it eliminates that smell and that it is more efficient.

Would I need to run both of them into a closed catch can so the fluids go to the bottom but then have another line coming from the opposite side on top sucking the vapors back into the intake? Would that cause that nasty build up.

Please let me know some opinions. Thanks!

 

[oldman]

http://www.dsmtuners.com/forums/showthread.php?t=254437&highlight=catch+can

http://www.dsmtuners.com/forums/showthread.php?t=263685&highlight=catch+can

 

[98gsspy]

I noticed the same smell after putting a turbo(and a catch can) on. I'll get back when I go out in the car see if it is coming from the can. That greddy can looks like it might do us a lot of good.

 

[SFRacingGST]

So from the 2nd link, what if i only have 1 breather coming from my valve cover, just just one line? Also will the setup work without a check valve for now? Wouldn't that replicate stock?

 

[oldman]

So from the 2nd link, what if i only have 1 breather coming from my valve cover, just just one line?

Don't worry about the second fitting, he was just being extra cautious.

Also will the setup work without a check valve for now? Wouldn't that replicate stock?

Yes but make sure you have a solid OEM PCV valve, you also can not install the 2nd catch can on the PCV side since there is no check valve to prevent the catch can from being pressurize.

 

[No_Skillz]

You don't want to use the breather. If you have it set up like it is in the 2nd link, you will be drawing air via your open filter into your intake tract. Since the point on the intake where the air is entering is after your MAF, it is unmetered and will cause you to run lean.

I used to use the RRE Catchcan with a cap. Honestly it's not worth the ~$50. Recently I've switched to using air filter canisters for air compressors. You can get them at Home Depot. Much cheaper and easier to use.

 

[SFRacingGST]

sorry for being so vague the first time. I have ditched the rre catch can and made my own out of pvc that are sealed. I have them running just like the diagram in the second link minus the check valve (on its way) and the second valve cover breather. I have a maft blowthrough so the air coming in the intake side is metered. When i installed it like this my dsm link setting were off, i had to bump up the 50 airflowslider 4-5 percent and my a/f's were still lean. How come? It is just like the stock config but with catch can's inline?

 

[oldman]

sorry for being so vague the first time. I have ditched the rre catch can and made my own out of pvc that are sealed. I have them running just like the diagram in the second link minus the check valve (on its way) and the second valve cover breather. I have a maft blowthrough so the air coming in the intake side is metered. When i installed it like this my dsm link setting were off, i had to bump up the 50 airflowslider 4-5 percent and my a/f's were still lean. How come? It is just like the stock config but with catch can's inline?

1. Like I said, you can't add the second catch can without the heavy duty check valve.

2. How was it setup before you made the changes?

 

[SFRacingGST]

Before was the pcv and the breather to a rre catch can with breather. I am getting the check valve, its on the way. however i have only ran my car at idle and when i put the check valve in there it is going to respond the same at idle since the valve will be open. Should i adjust my global to try to get my a/f richer at idle? I am alittle confused why everything changed so much

 

[oldman]

Before was the pcv and the breather to a rre catch can with breather. I am getting the check valve, its on the way. however i have only ran my car at idle and when i put the check valve in there it is going to respond the same at idle since the valve will be open. Should i adjust my global to try to get my a/f richer at idle? I am alittle confused why everything changed so much

So it makes sense that you have to increase air flow now that your PCV is again rerouted to the intake manifold introducing un-metered air into the system since you're running blow through. Instead of using the air flow slider, retune your fuel trims using dead time and maybe global first.

 

[SFRacingGST]

should i zero out my airflow, or put it back to where i had it before?

 

[oldman]

should i zero out my airflow, or put it back to where i had it before?

Yes, go back to it after you come close using dead time, this way the change will cover the entire range of part throttle situations when the PCV valve is open.