When you are modifying a small displacement turbocharged engine like the 4G63, the battle with positive crankcase pressure can seem neverending. Positive crankcase pressure is generated as small amounts of unburned air rush past your rings and into the crankcase. This air is known as blowby and excessive amounts of it can lead to premature engine failure.
To remedy this issue cars began designing positive crankshaft ventilation (PCV) systems, which were basically one way metallic check valves that would relieve this excess pressure. Your PCV system in your Mitsubishi Evolution is meant to reduce emissions and keep your vehicle as clean as possible.
Unfortunately this PCV system also recycles the old, hot, oily air back into your intake tract, raising temperatures and sullying sensors. This is not ideal for any turbocharged engine, let alone a MAF driven 4G63. That’s what our How To Install a Catch Can in a Evolution DIY guide is for, to help you install a catch can to deposit those PCV gases and fumes instead of routing it back into your intake system.
Today we’ll be showing you How To Install a Catch Can in a Evolution using our Project Evo, a 2006 Mitsubishi Evolution 8. This installation is not year specific and can be replicated on any engine, and is highly recommended for those with a mass air flow system.
We’re installing a universal style catch can, blue to match our Blue by You color. Begin our How To Install a Catch Can in a Evolution article by locating your Evolution PCV valve. This valve is located on the right side of your valve cover and is connected by a hose that runs to your intake tract.
Before you get to your PCV connection and install your catch can, you’ve got to figure out the mounting part. This is undoubtedly the hardest part of our How To Install a Catch Can in a Evolution because of how much space the factory battery and battery tray take up. If you have your battery already relocated in your trunk, this part is much much easier.
Using the main mounting bracket, install and mount onto your catch can so that you can mount this on your Evolution. Most catch can kits come with all the parts to completely customize your catch can installation.
We’ve opted to use the catch can horizontally, which allows us to implement the sight tube the long way. We prefer this method as it gives us a more accurate reading on how much oil and vapor is in our can when it’s time to drain it.
Now that you have your sight tube aligned the way you want it, mount your catch can as far away from your turbo headers and turbocharger as possible. We mounted ours on the right side of the engine bay on the frame of the Mitsubishi, near the stock boost solenoid mounting location.
The last part of your catch can that needs to be connected is the inlet ports, you’ll see two on this Greddy style catch can. You can either install the barbed fittings provided to you, or opt for a 3/4 pipe thread adapter to something like a -8 AN if you really want to get fancy. Check out our custom catch can install here for more details.
Now that you’ve got your catch can setup, you can now finish our How To Install a Catch Can in a Evolution Guide. Disconnect the vacuum hose that leads from your PCV to your intake snorkel. Cut this hose and cap it, as unmetered air will enter through this hole, causing a lean condition.
Connect the PCV inlet to your PCV valve on your valve cover. Secure all lines and hoses with the worm clamps provided. If you are connecting sides of the PCV, it’s best to leave the other port on your catch can open, or install a small breather filter.
When your catch can fills up, use your sight hose to monitor and then drain the fluid safely. When you drain your catch can, make sure to dispose of it properly.
Congratulations, you now know how to install a Catch Can in a Evolution! If you have any questions or comments, please leave them for us below!
