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Here is a plot of the Brake-Specific Fuel Consumption (BSFC) in units of grams of fuel used per kilowatt-hour, i.e. mass of fuel divided by the amount of energy at the output of the engine. Using this, a smaller number is better (more efficient burning of the fuel). The journal article only addresses temperatures from 20'C to 30'C and is for a 1.6L engine. But this is what I found quickly. The up-shot? All other things being the same, cooler air can increase fuel efficiency by about 3% to 5%.
Here is a quote from the conclusion:
Experimental work was carried out to study the effects of air intake temperature on fuel consumption and exhaust emission of a multi cylinder 1.6L gasoline engine. The tests were performed at variation of engine speed and a constant engine load with different air intake temperature (20'C, 25'C and 30'C). The results showed that the fuel consumption is improved with the decrease of air intake temperature regardless of engine speed. The lowest value of brake specific fuel consumption was occurred at air intake temperature of 20'C. For the emission analysis, carbon monoxide and unburned hydrocarbons were decreased with the decrease of air intake temperature regardless of engine speed. Combustion process at lower air intake temperature has remarkable results than compared with higher air intake temperature due to higher oxygen concentration. In conclusion, the lower air intake temperatures resulted in lowest fuel consumption and reduced exhaust emissions regardless of engine speed.
For a system that is supposed to bring in air from the outside, there must be a lot of heat radiated inside the engine compartment. I'll have to look up if there is any information on mileage and other performance improvements with using colder air.
What system are you referring to? Can you post a pic of it installed?
What system are you referring to? Can you post a pic of it installed?
It is not my cold air intake. I was commenting on the OPs post. I learned to use the word 'system' from my engineer colleagues for any assemblage of parts that work together; here that would be the inlet to the air-filter box, the box itself, the filter, and the hose between the box and engine intake.
What I thought interesting was how with so much air flowing through that I was surprised to learn how warm it got.
It is not my cold air intake. I was commenting on the OPs post. I learned to use the word 'system' from my engineer colleagues for any assemblage of parts that work together; here that would be the inlet to the air-filter box, the box itself, the filter, and the hose between the box and engine intake.
What I thought interesting was how with so much air flowing through that I was surprised to learn how warm it got.
Ok, you threw me off for a min. You quoted some temperatures in the same reply. Your post made it appear that you had something else installed in your vehicle that you got the ultraguage readings from.
Edit: PS, what IAT’s compared to ambient temps did you see after a longer drive? I’m guessing you’ve got the stock airbox/filter setup?
Last edited by Billy1820; Feb 13, 2020 at 04:07 PM.
Ok, you threw me off for a min. You quoted some temperatures in the same reply. Your post made it appear that you had something else installed in your vehicle that you got the ultraguage readings from.
Edit: PS, what IAT’s compared to ambient temps did you see after a longer drive? I’m guessing you’ve got the stock airbox/filter setup?
I have not had an excuse to go on a longer drive yet but when I do, I'll be sure to report it. I do still have the stock air-box.
I have not had an excuse to go on a longer drive yet but when I do, I'll be sure to report it. I do still have the stock air-box.
Sounds good, I’ll look forward to seeing your results. So I’m guessing you’re an engineer? Have you ever studied fluid dynamics?
Here’s an interesting tidbit, the stock airbox has a bellmouth, yet a tiny opening. I’m thinking the engineers who designed it needed to follow guidelines that met decreased noise levels while maintaining bare minimum airflow requirements for horsepower goals. A bellmouth intake would definitely help meet those requirements.
One more thing I didn’t mention in my opening post was the added benefit of this modified system taking advantage of the high pressure zone at the nose of the vehicle, adding to the density of the intake charge while at speed.
Last edited by Billy1820; Feb 16, 2020 at 06:37 AM.
Here’s a screenshot from my HP Tuners program of the stock tuning file for my truck. This is the spark advance correction table as it relates to IAT.
As you can see, spark begins to get pulled at 104 (F) degrees. As I mentioned in a previous post here, my stock intake setup was typically running IAT’s 20 to 25 degrees above ambient. Given that info, as soon as outside temperatures reached even 84 degrees, spark advance was being pulled by the ECU.
Continuing that same line of thought, with the modified air intake system, it would need to be at least 98 degrees F. outdoors before spark advance (and obvious loss of power) would begin to be pulled from the ECU timing tables
Last edited by Billy1820; Feb 16, 2020 at 10:43 AM.
I'd not go by the spark advance alone to figure if it hurts power. It may simply be that it needs to be pulled a little bit because the combustion is faster? So it may actually be a good thing it pulls ignition to get more power/torque.
