I get your point, powerstroker, but it really depends. From a HP perspective, I can't say that I disagree.

But if the engine is at the point where detonation is near, just a couple of degrees could make the difference between driving home or taking it home on a flatbed. That's why I used to have the "cold air" Web page in the "reliability" section of my Web site. So it really all depends on your mods and your tune (safety) and your usage (1/4 milers may want 1 or 2 HP, no matter what it costs).

I'm all about SAFE HP. It takes an aweful lot to outthink OEM engineers. I know several Ford engineers personally, and some are just plain geniuses (and if you think that they don't care about HP, think again). Think twice, cut once.

 

As should be apparent from my posts above, I don't see any debate at all. The theory is there. The real-world data is there. Enclosed filters are better.

 

Just to add to the debate. I've got a Volant intake which is a cone filter element inside a thick plastic heat resistant box that has the opening where the factory box draws air from. Then I added a hole in the bottom with a 2.5 in hose that goes by the HE to draw more cool air. I haven't done any type of testing but I figure this would flow more than stock sence the cone filter has more surface area that the stock panel filter.

 

My truck made 8 more hp on Swansons dyno just by removing the stock airbox and putting on one of his filter kits. This was on back to back pulls!
If you don"t believe me call Danny and ask him. Skip

 

What I’m trying to achieve is the best way to keep the temps down without an enclosed box. I know the goal is to keep the IAT1 {MAF} and IAT2 after intercooler temp as cool as possible. But what about the amount of air flow, that’s important too. It would be improvment to have a unit with the airflow as an open filter and the cooling of an enclosed ram- air.

 

One thing I keep forgetting to mention. That 10 degree difference people speak of can be much more when you start to compress that air with 10-15 lbs of boost. So any little difference will be multiplied on a forced induction motor. I don't remember the mathematical equation off the top of my head though. This is why we suffer so much more on hot days compared to NA.

 

Here I thought I had a decent idea and you went ahead and stole it. LOL I already have a 3" duct cut into my fender liner for when I had the open filter heat shield set-up. I just didn't want to cut into my $277 box quite yet and finish the routing. Not to mention I need to come up with a professional looking deflector so the incoming dirt doesn't spray directly onto my filter like before.

I have found that the best looking and professional parts are rubber brake duct and powder coated or painted spun aluminum intake bells on the fornt bumper or wherever you can find a cool air source.

 

Just remember on some dynos that do not have a powerful fan to compensate for air flow, the open air filter may show more HP because it's open and the truck is standing still but allows more air flow than the enclosed stock box which needs air flow like driving on the highway to get the air going through the fender well.

 

I believe that the dyno showed 8 rwHP.

But was this on a stock engine? If not, that would not be surprising, as the stock airbox gets choked off at higher airflows.

Was the hood open with a fan blowing on it? If so, not exactly representative of real-world usage.

Also, it would be interesting to try an enclosed cone filter of the same type. Remember, the question here is not whether a cone filter works -- the question is whether it works better when any particular filter is enclosed (with appropriately-sized openings for fresh air).

In a week or two, I am going to have Danny do a Predator or SCT tune for me with a 4lb pulley. I will dyno test the e-fan and swap airboxes at the same time (JLP vs. stock). My testing will be done on a fully warmed-up engine with a closed hood. I am not interested in bragging rights, just scientifically valid data on what I'm getting for my duckets.

 

I have never seen a dyno that can simulate real-world airflow. Even supplying 60 MPH wind over a portion of the truck would cost tens of thousands of dollars. But we need a fan that will supply 100 MPH or more over the entire front end of the truck to simulate what happens on a 1/4 mile run.

The cheapest solution that we could find was about $5K for a gasoline engine-driven squirrell cage blower that would provide about 60 MPH -- just to the heat exchanger. The costs increase geometrically from there.

We ended up having to run with the hood up. We were testing centrifugals, and the blowers were heat soaking with the hood closed. Horsepower was dropping like a stone on each pull. Which should attest to the importance of not sucking in underhood air.

The pole-mounted fans that most dyno shops use -- even those costing several hundred dollars -- are a joke.

 

Oldfrmtrk, Black Ice, While the theory behind the suggestion is valid, the practicality is a real stretch. ...it all all boils down to the fact that with the large volume of air going through the filter, and the (surounding air), filter, etc. inherent poor design as a heat transfer devices, flat surfaces, no fins, etc, any possible incremental decrease in air temperature entering the filter as a result of the small fan is probably not measureable with anything other than equipment from NASA ,but it wont hurt
people are always trying new ideas...figure out a way to use the cold (40-50F) suction side vapors of the A/C system piped through a heat exchange device in the intake air and I'll buy it ...

The improvement in air density from an enclose filter over an open filter is fact. The improvement in air velocity with an open filter over a stock box passed over the MAF is fact.

 

The engine is stock, under the Kenne Bell! The hood was up with a fan blowing on it. After we dynoed it Danny and I went for a ride with his scanner and as soon as we were moving the temp droped to about outside air temps. With a larger blower and more boost you need all the air rhat you can get.

You will be very happy with your truck after Danny tunes it! He is probably the best tuner there is, for these trucks.

I have had nothing but good things to say about my truck after Danny started tuning it. It even gets better fuel milage that stock.

The best part is that it is still a truck and I can tow or haul anything that I want to with no bad side effects.

Skip

 

Tim

No one has addressed the reason for the open filters which is at what HP / boost / rpm level does the stock airbox become a restriction and therefor is responsible for robbing power. Your arguments are ALL based on the assumption that the engine is getting the same volume of air in both scenarios.

Common sense tells us that MANY of the trucks HERE would be strangled by ANY of the closed boxes available.

Look at the pictures of the open filter from Suavy's dyno run with the turkey platter sized pulley - He ruined a HUGE open filter by imploding it...... Proof in my mind that his engine was demanding more air than even the huge open filter could provide.

I have a NGS scanner and before that an Autotap and live outside Dallas Texas - I have done quite a bit of driving around both watching the IAT's and logging them, using the 4 year old open PSP filter kit I have the intake temps go back to near ambient ( with in 10 degrees which = within 1 hp ) in less than 5 seconds of full throttle running. it is my bet that the scanners cant even keep up with the speed of the temp drop.

I agree - Your point that without a dyno in a wind tunnel doing good compares will not be possible. BUT the reasons for open filters are not as simple as Temp = HP. Many people like the look and the sound. And there are MANY MANY variables to consider.

Doug

 

I've mentioned this before to deaf ears, but I'll try again.
When I was testing/tuning with an SCT founding father, I had the truck dyno tuned with the open filter. I was thinking along the lines of Tim on the heat so I put the stock box back on with a k&N air filter. All other variables unchanged (as much as possible), the truck would detonate at WOT with the stock box. The idea/theory presented to me was that it's not just a heat thing, but there is also a change in the way the air flows over the mas which affects the reading. This in turn leaned out just enough to detonate.
We didn't scientifically document everything, so this idea won't hold up to scrutiny, but I thought it deserved mentioning.

 

Not true, Doug. I have explicitly recognized those issues several times in this thread.

Me: "If the engine needs more power than the opening to the filter box can supply, then the solution is to enlarge the opening in the housing, not to throw away the filter housing -- it is there for a reason. If the engine needs more air than the stock filter can supply, then the solution is a bigger filter -- and a bigger box around it."

Me: "Remember, the question here is not whether a cone filter works -- the question is whether it works better when any particular filter is enclosed (with appropriately-sized openings for fresh air).

So just to be clear -- the (non)debate is whether, assuming the filter in question is sufficient to supply the airflow needed for the engine, it is better to have an enclosed or open filter.

The looks and sound issues are subjective and therefore not amenable to scientific analysis.

FYI: I have the JLP box. For the sound.