A few things I dont understand on this topic (1) If you put your new intake in some sort of box to protect it from water or mud (like the one in the photo) why not just drop in a replacement style filter from K&N and (2) If you do not put it in some sort of box what are the chances of sucking in water while driving on the highway in the rain. It seems like a good idea to keep the filter protected from water but if you do is it even worth doing?

 

A lot of people just drop in a flat K&N or other higher flowing brand filter. The big thing here is to get rid of the restrictive resonator (Hemi hat) that sits right on top of the throttle body. That is where the major restriction come from.
A little straighter, smoother route for the air doesn't hurt either (hence the tube). And a cone filter has more surface area for slightly better airflow.
But there is nothing wrong with ditching the Hemi hat and utilizing the stock box with the drop in. You won't get quite the air flow as the full CAI, but you are getting rid of most of the restriction.

I have a 4.7 HO in my Grand Cherokee which comes stock with a "modified air intake" over the standard 4.7. It's basically a straighter shot intake tube. As a result, I'm simply using a drop-in inside of the stock air box.

 

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I actually ran in a monsoon, we recently had ten inches of rain in the northeast. I ran approx . 45 miles in really deplorable conditions. Everything remained dry for my set-up. As I had my doubts at the time.
I was gonna drop it in but my personal opinion was too get the cool air right from thye headlight assembly. I infared gunned it while driving. 9 I stopped and took a reading) Was surprisingly cool. So I left it as you see it. hope it nhelps.

 

The True Flow intake pipe on my truck goes from the air box right to the TB, replacing the hemi hat. I think for right now I will leave it alone, it's already been urgraded.

 

I'd like to see a dyno read out of a Hemi hat vs no Hemi hat. Volant, who I have much respect for, claims they KEEP the Hemi hat because low-end is lost without it (which the Hemi lacks already)

Although I haven't bought a CAI yet.....I had a Volant on my 6.0 Silverado and loved it.


So is the Hemi hat that restrictive if so many say 5hp is about all you gain with a CAI ?

Curious....

 

Who is this Physics person? We should get him on the forum. I bet we can change his mind....

 

im w/ most people here, make your own. Save a 200 bucks and get the satisfaction of DIY

 

What the hell are they putting in the water up there in Ulster County, NY? Low end loss is a direct result of BACK PRESSURE which by definition is caused by restriction IN THE EXHAUST SYSTEM! A reduction of air in the intake can not physically effect low end torque in a positive way.

Now I could be wrong if the laws of physics have changed since I learned all this stuff. If so, please enlighten me with some facts.

I actually think Volant's own advertising contradicts ANY benefit of leaving the stock "Hemi hat" on the vehicle:

Volant Air Filter Box: Our Cross-Link polyethylene box is engineered to each specific application for low restriction and an increase in air volume. It insulates and protects the filter from engine heat, moisture, dust and debris to provide colder air to the engine for an increase in horsepower.
Volant Air Duct: Factory air inlet ducts use sound baffles and awkward bends which restrict flow. Our Cross-Link polyethylene air ducts are sculptured to give the engine less restrictive breathing. Incorporating larger diameters and unique bends, that can't be duplicated with metal ducts, allow for maximum airflow velocity and throttle response.

Why would you go through such pains to increase air volume and reduce restriction and leave the most restrictive part on the chain in place? As with ANY other system, it is only going to be as strong as it's weakest link.

Also, a 5-10 HP gain at the rear wheels or 10-15 HP at the crank is fairly significant not to mention the fact that DYNO confirmed data proves that the addition of a CAI increases the gains of other mods such as polished heads and headers.

You've got my curiosity up though, I'd like to see a dyno with JUST removing the Hemi hat. The closest thing to that I've ever personally witnessed was a dyno of a TrueFlow system where their drop in was put in the stock air box and the their tube replaced the Hemi hat AND tube to the air box. The gain on the dyno was just under 7 HP...

 

So this would be a setup like lx has and is that 7 at the rear wheels?

 

In the case of a BFI, it goes from a larger inlet to a smaller outlet. So funnel physics, the same volume of air being pulled in must also exit. Since there is a change in diameter, air speed increases thus shoving the air into the throttle body. It provides more air than what the engine will pull in on it's own. It's not going to be nearly effective as an FI system but it does produce noticeable differences over putting ****ter pipe on your truck.