"Cold Air Intake" Vs. Short Ram Intake (SRI) Part 2

As you can see from first part of my series Short Ram vs Stock Cold Air Intake Part 1 I have successfully installed my Short Ram Intake.

I am doing experiments to investigate 3 things. How has this effected my truck's miles per gallon? The truck's miles per gallon sometimes increased by 2 miles per gallon, but 1 is more accurate to say as an average. What effect does it have on Horse Power at the wheels or wHP? Are the changes different in the city than on the freeway?

I installed this with the hope that the Shot Ram Intake or would increase my truck's miles per gallon. In the city, in the winter, I am now getting better miles per gallon for my truck, then when I was driving on the freeway before. That sounds completely counter-intuitive, right? Let me explain.

The first gas tank I ran my Torque App's miles per gallon versus hand calculated where you take how many miles you've driven since your last full tank of gas divided by how many gallons of gas it takes to fill up you gasoline tank all the way again. I used the same 87 octane from the same Shell gas station and same gas pump every time. I stopped filling up at one click for some tanks, but I had to switch to 3 as my gasoline tank' vent sometimes prevents a full fill up by as much as 6 gallons. I also use 2 oz. of TCW-3 oils per 5 gallons. I consistently did this prior to the one variable change of the intake as well so continuing this is a control to increase accuracy of the experiment. I'll have to address with a later article how TCW-3 oils have improved my truck's miles per gallon. It's similar to how Lucas Upper Cylinder lubricant helped me, as indicated by this link to a very popular video I made about it.

Prior to the Short Ram Air Intake, the truck got 14.3 miles per gallon with very little driving other than my commute to and from work. As traffic is usually the same and the way I went there was always the same, this helps reduce variable changes. Afterwards, the truck got 15.9 miles per gallon for the total commute. I got as high as 16.3 miles per gallon, but that was commutes when from the teens and 20's in degrees F to as high as 55 degrees F. My truck did get better miles per gallon as it gets warmer, and in fact the Short Ram air intake didn't actually improve for warmer weather gas mileage. It just matched it.

Please save this web page to your browsers favorites. I've only been running the Short Ram Air Intake for a couple of weeks. It's been cold and it's been like spring or fall instead of winter as well all in a short time. If I can get some more consistent weather, my truck's miles per gallon pay vary.

Now on to wHP or HP as measured at the wheels. I am using the Torque Pro App to follow OBD II data and test for how much power I have on a graph on Wide Open Throttle or WOT runs. I'm just working within the speed limit on the same on ramp onto the freeway. So far it appears that how much wHP wildly changes, but when you compare it up to the temperature at the intake air temperature sensor, or IAT for short, the colder the air the more wHP. The warmer? Less. Both intakes produce the same power. The weather determines wHP.

So far, all the Short Ram Intake has done is reduce my wHP like it's a warmer day when it isn't. On the freeway it is in fact running only a degree C or 2 hotter. In fact, it seems that on the freeway my miles per gallon has decreased. This tells me that as it's sucking air on the freeway behind the headlight it's getting colder air than what's available to the stock, fake cold air intake. What's nice however, is that the city miles per gallon has increased tremendously. This is when my IAT is showing much higher temperatures than I normally would in winter or unseasonably fall or spring like weather.

Source: Why a Short Ram Intake? The reason will surprise you. by DENichols

Short Ram vs Stock Cold air Intake (CAI) Part 1

On my Generation 1 V6 2004 Nissan Frontier 3.3 L XE...we have a *stock cold air intake. It's winter now and like a lot of us, I have watched the MPG's go down 2-3 points. (*see below for 2 week update!)

Stock "Cold Air Intake" commonly known as an air box.

The filter is high and far away from the IAT stock location.

When driving slow the IAT will sometimes see much warmer 

temperatures than what the pod filter is seeing. I believe it's 
actually drawing a lot of cold air from behind the head light.

I was thinking a hot air intake or short ram intake might work to boost MPG's I am interested to find out if there are other performance changes, good, bad, or none. The next picture I show you above of the stock cold air intake with the conical filter really doesn't work as there's no where for one of the tiny tubes behind the air box to connect to anything, but it had a valuable lesson while I had the shiny tube missing.

The MAF air flow sensor is hooked up nicely, but this leaves the IAT or intake air temperature sensor floating away (above) the cone filter and it's not actually in the air pipe, which the filter is drawing air from like on stock. When you're driving slow the fuel trims spiked all over the place rich sometimes. When on the move the IAT is accurate enough.

Once I located the missing pipe and installed it completely, the conical filter is actually touching the wire side of the IAT, which I think is important to do as now the fuel trims are stable even when driving slowly (less air coming in when you're not moving but at least the air is being drawn next to he IAT now so fuel calculations are much more accurate). (needed to replace the factory zip-tie holding the MAF sensor wires away from the pulleys)

2 weeks later update:

The next series of photos will show you that the stock cold air intake that we Nissan Frontier owners believed we had was just a trick of the manufacturers. You see the pipe that has the red rag in it below? I was trying to block the cold air source, but it turns out it supplies no cold air. If you look at the next to pictures, you can just make out below the short ram intake filter, you can just see the picture of pipes which are in the engine bay. They are the actual source of air for the pipes that "go into the fender well". I see this all the time on car after car. No manufacturer wants to have a real cold air intake. They'll make it look like there is one, just to design in some feature that makes the apparent design a lie. I'm sure it helps emissions and lowers power however, as colder air does mean more power if your fuel pump and injectors can keep up.

Notice the red? It was my attempt to raise the temperature for the intake, but it turns out no air comes from there! See below!

At the bottom right corner is the pipe shown in more detail next.

The IAT (Intake Air Temperature) sensor is on this pipe, which goes into the fender well and back into the engine bay via the original air box.

Source: Get Rid of your Short Ram Intake! by DENichols