what is a bypass vavle for a cai?

 

The bypass valve is a normally sealed part of the intake tube that will open if pressure at the filter suddenly gets really really high. For example, if your car sucks up a puddle through the air filter, that causes the vacuum in the intake to shoot way up. That pulls the bypass valve open and allows air in, so your intake doesn't suck that puddle into your engine. It's a must for any cold air intake system that mounts down near the wheel.

 

so what happens when water gets in your engine? does the bypass prevent it?

 

If water gets in your engine, bad things happen.


Water is harder to compress than air. When your piston comes up to "squish" the water, it comes to a very rapid stop, potentially shattering the piston, bending or breaking rods, bending or breaking your crank, and possibly shoving pieces of rod, piston, or crank out of your engine block through brand new holes.

 

so you don't hydrolock you motor, water doesn't compress very well.

 

how can you prevent this?

 

Don't drive through big puddles.

 

Even with a bypass, I would be very careful around water. Also make sure to mount it as close to the filter as possible. I've seen a kid put his right at the intake manifold which didn't do much good.