Thursday, January 18, 2018

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