Diesel air intake warm or not

[RustyLugNut]

Originally Posted by JasonG

Where did I ever suggest that the laws of physics changed in my engine?

Please contact your engineer friend and ask if they can clarify for us how the injection computer responds to the IAT input sensor.
That knowledge will provide the conclusive answer that we are all just guessing about.(myself included)

The more important question is: "what happens to a fuel droplet when injected into an increasingly hot combustion chamber?"

The response of the engine's computer to the IAT (intake air temperature ) is a programmed response that will vary tremendously from application to application. Of course that is what you seem to be driving at. That, your application will react differently than theirs to the modification of sensor readings such as IAT. From this you hope to gain a fuel efficiency benefit. I stress that understanding the droplet reaction that is the underlying framework for the diesel engine designer in the first place, is essential.

I am not stopping you from fooling with your particular vehicle's sensors. But, with greater understanding comes greater control. What do you hope to control and why?

[euromodder]

Hägar never got its best FE when it was hot outside - even when not using AC.

Sweet spot was around 20°C.
Cold enough for the engine to be more efficient.
Not cold enough for the denser air to cause much extra drag

[JasonG]

Originally Posted by euromodder

Hägar never got its best FE when it was hot outside - even when not using AC.

Sweet spot was around 20°C.
Cold enough for the engine to be more efficient.
Not cold enough for the denser air to cause much extra drag

Looks like my weekend trip agrees with your statement.
When I got in my wifes car the MFD was showing 46mpg, normally it hovers around 44.
The trip (with me driving) was 48 range.

Looks like the warm air intake stays for the winter and the
Snorkle gets reconnected come summer.

[redpoint5]

I would think that since cooler air increases the effective compression ratio, this would also increase fuel economy. After all, there is a reason the turbo charged air is run through an intercooler.

Originally Posted by mechman600

A bit of a side note. Unplugging the intake manifold temp sensor and installing a resistor to make the ECM think it's cold advances the timing on some engines and does wonders for mileage. I repeat: SOME engines. Cat engines: 100 ohms = indicated 7F. Cummins I'm not sure, but I could easily find out.

Old post, but I would be VERY interested to know if the Cummins can be hacked with this easy mod and get good results.

Originally Posted by mechman600

A mechanical adjustment depends on the year. 12 valve B5.9s: yes. Big difference. 24V electronic ISBs: no point. The timing is electronically controlled in the VP44 injection pump. Adjusting the mechanical timing of the pump won't have much of an effect. I know some aftermarket tuners only alter fuel metering while others alter both metering and timing. For economy you would obviously want the latter. I would go with a tuner before tinkering with various resistors in place of sensors with the Dodge. On the other hand, resistors are really really cheap.

I've got a VP44/ 24V ISB, and a Juice With Attitude tuner that I have heard can improve both power and fuel economy. The problem is, I have also heard a handful of stories that the moment someone tapped the fueling input with a tuner, the VP44 gave up the ghost. This could just be coincidence since those things are failure prone, especially given the notoriously awful lift pump.

That said, I have always been chicken to tap the line for fear of being out $2k on a pump. Also, my transmission has been on its last leg for 40k miles, and I didn't want to put a nail in the coffin... I'm starting to get curious again though. Maybe if I just treat the throttle gently

Originally Posted by JasonG

Looks like my weekend trip agrees with your statement.
When I got in my wifes car the MGD was showing 46mpg, normally it hovers around 44.
The trip (with me driving) was 48 range.

Looks like the warm air intake stays for the winter and the
Snorkle gets reconnected come summer.

Perhaps the snorkel adds drag, which by removing, bumped your MPG. While I appreciate that you reported the numbers, there are too many variables at play for me to conclude that warmer air was the primary factor for the improved mileage.

I'm always more interested in the deductive reasoning behind why something behaves the way it does, and less interested in the inductive reasons. Anecdotes fall into the inductive category, and while valuable and worth consideration, always leave room for uncertainty.

[gumby79]

https://www.google.com/url?sa=t&sour...p7benxIxptTjGQ

What I get from article

If intake or under hood intake air temperature is 75 º F at atmospheric pressure (14.7psi @ sea level) the turbo outlet temperature will be 285 º F at 20-psi boost. And the IC should drop that to about125f-100f @the valves

90f or higher IAT = loss of power @1%per10°f and fuel efficiency eg:

A 250-HP engine will develop only 240-HP if the air temperature is 130F (54C)
using the same quantity of fuel. Less work more fuel
Cummins retained the 160hp rating on pre91.5 with larger injectors 4x.012" water to air cooler. Vs 91.5-93 got 6x.009" and the air to air intercooler smaller injectors less boost with the same 160hp is a good factory example what happens when you go cold air

1st gen pre 91.5 has the water jacket intercooler that works with newer 12valve and maby 24valve heads. Blockheater is able to heat intake air@ plug in with coolent.

[gumby79]

The best iat control I can think of would be a auto temperature control door (like in the AC of newer cars) that mixes air from the fan shroud or exost manifold with fresh to maintain the correct IAT . It appears that the correct temp is actually a window of 60-90f. Too hot air is to thin
Too cold retards the timing so that not all fule is able to burnt= smoke and fuel washdown increasing service intervals. Also the marine pdf was talking about condensation in the cylinder causing extraordinary wear and maintenance including being the ultimate reason for a 100,000 motor lasting only a 10% lifespan

[ConnClark]

Originally Posted by gumby79

https://www.google.com/url?sa=t&sour...p7benxIxptTjGQ

What I get from article

What I got was this guy doesn't know what he is talking about on why intercooling works. Not one mention of the reduction of combustion gas temperature rejecting less heat to the cooling system. He also made the False statement that an intercooler alone can't add power. This has been shown experimentally. He just chalked the fuel economy improvement to "favorable combustion conditions".

The reduction of combustion gas temperature rejecting less heat to the cooling system is considerable and offsets many drawbacks such as slower ingnition.

[slowmover]

A decent thread on CumminsForum in Third Gen on WAI. Cross reference "winter".

110-130F looks good.

[ConnClark]

I have said it before and I will say it again. If you put a warm air intake on your diesel you will reduce fuel economy and increase pollution.

It is just a bad idea unless you are operating it at -20C or other insanely cold temp

[gumby79]

ConnClark [I have said it before and I will say it again. If you put a warm air intake on your diesel you will reduce fuel economy and increase pollution.

It is just a bad idea unless you are operating it at -20C or other insanely cold temp

It said
For every 10º F temperature
increase above 60ºF the changes to air density and oxygen content results in a power loss. Power loss is 1% for every 10F above 90F.Increased smoke and particulate replace the lost power
This is why the 1989-1991 dodge Cummings has .0004524 cross section. 4hole X .012 "larger injectors "

the 1991.5-1993had .0003817 cross section 6hole X .009"small injectors"
same make and model they both have 160.hp
the 1989-1990 had Water Jacket Charge Air Cooler placed inside the intake manifold. 22-25psi max boost with 18cm housing, IAT constant @ 180-220°f. (-20°f ambant =180-220°f same as coolant for IAT @full boost;off boost IAT =180-220°f ) Extra fule is necessary for cooling to compensate for high IAT

Late 1at gen 1991.5-1993 my truck small injectors Air toAir Charge Air Cooler 15-19psi max boost 21cm housing. IAT with in 50°f of ambient( -20°f ambient =30°f. @full boost off boost IAT COULD DROP TO-20°f )

Hot Aie Intake would be a pluse it would have to be dynamic based on IAT@the intake manifold.
To tie your grill block shutters in as a HAI set probe on the hot side of the intercooler set to close @below 90°f and open above 130°f

We (you me and the author ) agree excessive IAT =high NOXX
It also said genraly a 1:3 IAT to EGT.

ConnClark What I got was this guy doesn't know what he is talking about on why intercooling works. Not one mention of the reduction of combustion gas temperature rejecting less heat to the cooling system. He also made the False statement that an intercooler alone can't add power. This has been shown experimentally. He just chalked the fuel economy improvement to "favorable combustion conditions".[/I]

3. Higher N0x emissions
Increases to charge air temperatures result in higher combustion chamber temperatures
which in turn increases the production of N0x emissions. Normally, nitrogen, which
makes up approximately 77% of the composition of air, remains inert and uninvolved in
combustion processes. At temperatures above approximately 2,500F and because of high
cylinder pressures, nitrogen will react with oxygen to produce nitrogen oxygen
compounds collectively known as N0x.
[I]
And



If IC only cant make power ? Then how can Cummings put smaller injectors and a better IC, and not loose any power . how is useing less fule to od same work not a FE improvement

In conclusion testing is needed to deturmen if your situation will benefit from HAI. With TDI HAI is NOT the answer an active grill block is.

We all benefet from shaired knowledge

As for insane cold this winter @5550ft it wasnt bad @-33 low and 15°f average for feb 2014 most days below 0°f and Butte, Montana was the 18th coldest city in the lower 48.

So yes I live were this subject is of high importance for me 15-20 miles to reach operating temp @65mph. Can cut that down to 7-15miles with a 75% grill block. Would go 100% except on grades 7%and grater I'm geting worm 200°f @30°f ambient @top of grade EGT started climbing ATACAC was giting heat soaked noticeable power loss increased hase in exost.

With an active grill block and also active HAI pulling from behind the radator/fresh air on a thermostat would help my worm up time/FE.