The single 3" is nearly unrestricted and you wouldn't need bigger unless you built a monster of a motor with a massive throttle body

 

Alright so I finally finished mine. I used 2 grand Cherokee intake parts. Still need to do a few cosmetic changes but looks and works great. Filter fits perfectly btw with how I trimmed the PVC.

 

I made an identical mod on my Miata and here's what you are really getting from it.

At best, you are recovering horsepower lost from using heated intake air under the hood. Intakes are built from the factory this way for consistent performance over the life of the vehicle. The lower temperature of a true cold air intake path ensures the highest stock horsepower available - not more of it. You also usually get a little more throttle response and whatever powerband/torque improvements are available - good reason to keep the total path as short as possible. Especially noticed during colder weather, there should be more response but hardly anything monumental - a very worthwhile mod for the money.

I'll be doing this on my '96 Cherokee when it warms up a little...

 

On my XJ's I don't do this for the performance increase. I did this to avoid taking in water when crossing. In a stock XJ intake setup water above your bumper is touching the airbox. Water at the headlight is already a serious problem.

 

i will be doing this the same as dukie this coming friday.. i have a few ideas on how i might tweak it a little, i will keep you updated...

 

So if I drill. 3inch hole into the cowl and put the open tube in there did any one drill holes in the pipe it self just in Case water gets there

 

I wouldn't do that because then the engine would also be sucking air through the holes you drilled there quick might include water anyway; defeating the purpose of the cowl snorkle.

 

^ This. Not necessary

 

My comment is not necessary or drilling the holes is not necessary?

 

Nice job on the intake hoses/snorkel.
But, what do we do about the exhaust pipe that will be in the water also ?

Randy

 

As long as you're on the gas and your pipe is Angled down you should be fine, if you're really concerned you could run it out and up above the roof like the humvees have em now

 

Water WILL NOT get into the intake. The cowl has drains that, if they are not clogged, will prevent the filter from getting wet. The bottom may get wet if you take on a lot of water (Heavy rain at highway speed or you dunk the hood entering a body of water) but it's not likely to take on enough water to cause the engine harm.

The way water causes harm is if a very large amount of water gets sucked into the cylinders, like a cup of water for example (might be more, might be less), and the piston comes up in the compression stroke. Since water can not be compressed that causes things to break, from whta i know most likely the piston itself or the rod connecting it to the crankshaft.

 

So you just put the PVC flush with the cowl wall and no water gets in it all drains out the cowl holes an your fine?

 

yessir. The inlet ends up about an inch above the floor of the cowl. Drains are large enough that water never gets in. Mine has been thoroughly tested over and over again.

 

I wanna build mine this weekend what all did you use to cover the old air inlet on the box