Another Snorkel Experiment

I was driving around in the rain yesterday and was wondering, how much water gets in through the snorkel? And how much can get in before there's a problem...

AEV says the ram scoop has a special way of getting rid of water. While I have no idea how this works, or if it works, I figured I'd be the devil's advocate and go with "it doesn't work".

So I decided to chuck 500ml of water into my airbox and see what happens. I reckon if 500ml of water gets through the snorkel, then you're driving in some sort of monsoon. So in it goes, and I set the timer to see how long it takes to drain out.

To my joy, it all drained out in no time. There is no way that you'll be able to get more water than that through the snorkel. If you're getting more water than 500ml/min into your airbox, I strongly suggest you stop what you're doing. You're probably underwater or something like that.

So yes, driving in rain, even heavy rain at that, with a snorkel is perfectly safe with no risk of getting water into the engine.

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Some Snorkel Thoughts

That time has come again, and I have cut a hole in my JK's hood. Why? Well, to fit an AEV snorkel of course. Here's a link on a write up I did for my first AEV snorkel http://jk-overland.blogspot.com/2010/10/aev-jk-snorkel.html.

Anyway, why fit a snorkel? If are your reasons are anything like this...
Then don't even bother.

So if they're not for deep water, then why?
Well let's take a look at what AEV say about their snorkel.

"Providing your engine with a clean supply of air is critical to your vehicle’s performance and longevity. AEV’s JK Snorkel air intake system is the essential engine protection accessory for overland adventurers whose exploration includes deep water crossings and dusty dirt roads."


Clean air supply? I both vouch for this, and disagree with it. If you use the optional pre-filter, then absolutely yes. That thing just sucks up everything that tries to get past it. In my previous JK I put in a new filter with the pre-filter. Couple of thousand miles later with the pre-filter and the airbox filter was still spotless. That was really cool.

Ok, next up, deep water crossings..Well, how deep do you want to go? If you in water deeper than your hood, you're in pretty deep water. Sure a snorkel raises your intake, but this doesn't make your car a submarine. So even with a snorkel, be careful. Diff breathers, electronics etc are still as venerable as before. 

But here's an interesting thought...
I figured, it must be logical that cool air from outside, will be colder than air under the hood getting heated up by a 100'C engine.
Cooler, dryer air is better for engine performance. The cooler and dryer air is, the greater the air density. This simply means there's more air molecules per volume.

So I set out to primitively collect some data to prove this.First, I put a digital thermometer in my airbox without a snorkel. The air in the airbox, with fan blowing, while idling was 60'C! That's pretty hot air. Add that to high altitude like Johannesburg and air starts getting rather thin.Next up, I went for a drive around the block.That afternoon the snorkel went in. And the next day I set out to repeat the experiment.


Cleaner air with the air ram? Hmmm, I'll have to say before I can comment real. From what I've heard they do an ok job. But I've also heard of them sucking all sorts of leaves and small bugs into the airbox. I know people say dust settles closer to the surface and the snorkel sucks in cleaner air from higher up. However, from my experience in driving in convoys, there's dust all over the place. I can't see how an open scoop can draw in less dust than a filter under the hood. People say they do, but I'd like to see for myself.

And more air molecules per volume, means more air molecules for the engine to mix with fuel and turn into awesome noise. 

Temperature while driving (24'C outside ) at very moderate town driving, the temperature in the airbox settled at 48'C. Slightly better with air flow.

Same time of day, 24'C outside with snorkel now.

Idling temperature? 47'C! 
Driving temperature? 27'C!

That's about a 20'C difference all round! That's gotta count for something?

After some calculator fiddling using the two days temperatures, humidity and altitude, I worked out that with the snorkel, the air going into the engine is 8% denser.
What this does for a 3.8L V6? I don't know. I'll have to find performance charts to see what increase in HP that is.

I also chucked in one of these. Synthetic gauze filter from Rugged Ridge.

So, in combination of this high air flow filter and cooler air from the snorkel, is there a noticeable difference in the performance? Naaah...

BUT! There definitely is a difference in the drivability of the JK. Cruising around town feels a lot easier on the engine. You can cruise around town comfortably and keep the RPM in the little green eco range.
Which is cool. I've already seen a 0.2L/100KM drop in fuel consumption. I'm sure it'll get better. I just haven't been driving enough for it to have much of an effect.

So is a snorkel worth it to me? Yeah for sure. It's a simple mod that could have many benefits and potentially save your *#$# off road in water. So why not?