New Catch Can upgrade

[Tony Davila]

Originally Posted by 5ABI VT

What are your guys thoughts on a pcv + catch cans + Piping from catch can to the header collectors (scavenging? forget the term for it).

I have already tried that, it doesn't work. I got 1" of vacuum at idle and nothing all the way to 7000RPM. It won't work with a muffler system because it creates some back pressure. I ran a vacuum gauge to the can and tried the EVAC header system. So forget about it and save your money. Engine vacuum or vacuum pump will work fine with any catch can that provides oil droplet separation.


I no longer have this B&B exhaust system, I have OEM with cutouts.

[5ABI VT]

Originally Posted by Tony Davila

I have already tried that, it doesn't work. I got 1" of vacuum at idle and nothing all the way to 7000RPM. It won't work with a muffler system because it creates some back pressure. I ran a vacuum gauge to the can and tried the EVAC header system. So forget about it and save your money. Engine vacuum or vacuum pump will work fine with any catch can that provides oil droplet separation.


I no longer have this B&B exhaust system, I have OEM with cutouts.

Very cool. I do believe the b&b is incredibly restrictive. ive seen inside the mufflers and I really wish I kept my earlier system I know the later version I have now is seriously walled and baffled its like a maze inside.
I always like to tell people to make a deep bassy/boomy sound with their mouths.. in order to do that you have to really restrict the airflow.. = b&b

[5ABI VT]

Originally Posted by Tony Davila

I have two PVC valves at the entry point of my canisters. I believe the size is of the vacuum port of my cans are 3/8" inner dia.

IH port side on the can is 3/4" to accommodate the PVC then reduced to 3/8" which then connects to the IH port tube.

Left can is connected to Left side IH. Right side can connected to right IH port tube.

Vacuum source is shared via T connector.

Below is a diagram for a single can I built for a couple of Z buddies.


Below is a can I built for a L98 which is to be mounted under the passengers headlight.


Yes........... this are used propane tanks.


Single Canister mounted onto my buddies Z. This is the drivers side.

Trying to get a wrap on the pcv system but I have so many things on my mind and projects going on .

SO there are 2 pcv valves? Are they seperate valves/lines doing the same thing? Just wondering if I should go 2 cans instead of 1. Are there any photos of the pcv system anywhere?

[Tony Davila]

Originally Posted by 5ABI VT

Trying to get a wrap on the pcv system but I have so many things on my mind and projects going on .

SO there are 2 pcv valves? Are they seperate valves/lines doing the same thing? Just wondering if I should go 2 cans instead of 1. Are there any photos of the pcv system anywhere?

The picture below shows where I installed the PVC valve, I did this on both cans. They are inline sandwiched in between the hoses. After studying the purpose of the PVC valve I have determined that they are not necessary for my set up. They are basically a one way check valve that opens with vacuum and in the absence of vacuum crank pressure would push them opened anyway. So I believe they are not necessary unless you just want to install them because you want too. Hope this helps.

[XfireZ51]

Thought I would resurrect this topic for a bit. My catch can has been installed now for about 6 weeks. With several catch can threads active right now, I wanted to ask if anyone has noticed a change to their exhaust. How do your tips look? Has there been any noticeable change?