2wd Regular Cab Shortbed with 318, 127 miles at 55mph on straight flat bridges from Key West, to Miami.

 

The gauges are never accurate with MPGs, as they don't measure fuel into the engine, just air. I bet that is as accurate on MPGs as the factory overhead consoles.

Only way to calc accurate MPGs... number of gallons on the pump divided by miles driven. And then you have to factor in the fact that some people don't correct their speedos for larger tires... lots of math.

No idea if my SCT can measure the IAT, will check it out this weekend if it can. If so, will get you numbers for my Volant.

 

I knew a few wouldn't really believe me, and that is fine, but my wallet can vouch for my mileage. I figured it on paper too. My best was 22.65 mpg (This 80% highway miles). As soon as I got to Key West, I filled up the tank until I heard one click from the hose and then I reset the trip on the dash. When I got to Miami on the way back I filled up again until I heard one click. Then, divided the miles driven on the trip by the gallons on the pump. Stock size tires too. In 4 days I traveled 444 miles, and still had a little under a 1/4 tank of gas.

Here is a pic of the receipt.



444 miles / 19.597 gallons = 22.65mpg


Sorry for going off topic Aim! Back to air cleaner data.

 

I did this temp game back when I was experimenting with different air cleaners. I recall that it is true that the round filter sucked in the hottest air, but the K&N FIPK I had was sucking in air that was only about 5-10 degree colder when at stop lights and slow speeds. Even with the front flap removed from next to the radiator, it took several minutes of driving for that air to translate into temps at the IAT.

On our trucks, the PCM really doesn't give much emphasis on temps when it comes to adjusting fuel anyway. If our trucks used a MAF sensor, it temps would mean a lot more to our trucks, and CAI's would yield better results. So unless you find an intake that gives you significant temp differences, the computer isn't going to make much or even any changes to fuel or timing anyway. This is why I believe that on our trucks, having more air of any temp is better then equal or less air that is only slightly cooler, hence why I like the round filters better. Not everyone agrees with me, but that is just my opinon from the tests I did on my truck and what I felt worked best for me.

I posted more about this here in the last round of "I'm going to relocate my IAT" threads.
https://dodgeforum.com/forum/2nd-gen...on-pics-2.html

I'll see if I can find the data I had on this back when I did this temp experimenting. I used to have a notebook full of data I was gathering from stuff I was doing on my truck, and I haven't been able to find it lately.

This will be a good thread once we get somemore results in it. We should sticky it in the DIY of somewhere that makes sense.

 

Silver,

I agree completely, I'm looking for at least a 40*+ swing or I don't believe it would be worth it.

Also, I will have to assess whether the said setup flows as much as the TB can handle at WOT, or I'm losing performance as well.

I'm still leaning toward the ram air setup being best, just still a little leary running something like that in a rain storm. Need more data on that.

 

Hhhhmmm......

For the PCM to find the VOLUME of air coming into the engine, since it isn't measuring it directly, it is going to need to do some math to figger it out. One part of the equation is temp. On a map car, the IAT IS going to have more of an effect on fuel, than a car with a MAF. At least, that seems reasonable to me??

I think the biggest problem with a lot of the so-called "cold air induction" systems, is that they take the air from the same location as stock. Out of the fender. Where does THAT air come from? The holes in the fender leading into the nice, toasty warm, engine compartment. Sure, there is a bit of outside air that makes its way in there when you are driving at some speed, but, for the most part, the benefit from the CAI is the fact that if flows more air than stock, and that's about it.

If you could manage to get air into the engine that DOESN'T pass thru the engine compartment.... via the ram air, or cowl induction (sealed off from the engine compartment) you would see the most benefit. Question becomes, how much of a temp drop do you need for the good ol' butt dyno to see it?

According to what I have read, for each ten degree drop in intake air temp, you can take a tenth of a second off your quarter mile time. Yeah, real big concern for us on these trucks eh?

 

For volume, the PCM will just use the down stream o2 reading (at least that's how I understand it in the PCM tables). If you have a lot of air coming in via a high flowing air cleaner, that o2 will start to read lean, so the PCM will compensate by boosting fuel accordingly till it sees what it likes on that sensor. Again, it is not based on temp, it is based initially on MAP, and then subsequently on these downstream readings. IAT temp readings play a very small part in adjuting fuel or timing with our PCM's. That's why I like volume over temp on our trucks. Now if you get a custom tune, you can control that more.

I agree completely that a ram air is the best way to go on our trucks. I hope to have some kind of ramair setup someday when time and money permit.

 

Guess I am just used to GM systems. (with unheated O2 sensors....)

What about WOT? Does the PCM still pay attention to the O2 sensor at that point?

Open loop operation?

 

No, WOT and warm up (open loop) O2 sensor data is ignored. Trying to run 14.7:1 at WOT would spark knock like a mother.

 

My mother doesn't spark knock at all, as far as I am aware......

That's kinda what I thought. So, there are times when air temp would play a role in fuel trim. Albeit, I still am not entirely sure just how much of one. Still, colder air is 'free' horsepower, whether it justifies the expense you have to go to to get it is another question entirely. (and the whole point of this thread?)