How many of you are running hot air intakes?

[cfg83]

Hello -

Would a glow plug or self heating 02 sensor work for this? You don't have to connect the 02 sensor voltage output. I can think of these caveats :

1 - Too hot, melt something.
2 - Amperage requirement outweighs FE benefit.
3 - Wouldn't heat up intake air fast enough.

Glow plug only :

4 - Not designed for continuous use.

What do you think? I just don't know. I am trying to think of low amp, safe, heating elements, and I don't know what would work. How about the guts of a popcorn popper?!?!?!?!?

CarloSW2

[usedgeo]

Originally Posted by cfg83

Hello -

Would a glow plug or self heating 02 sensor work for this? You don't have to connect the 02 sensor voltage output. I can think of these caveats :

1 - Too hot, melt something.
2 - Amperage requirement outweighs FE benefit.
3 - Wouldn't heat up intake air fast enough.

Glow plug only :

4 - Not designed for continuous use.

What do you think? I just don't know. I am trying to think of low amp, safe, heating elements, and I don't know what would work. How about the guts of a popcorn popper?!?!?!?!?

CarloSW2

You can google "12volt electric heaters." One would probably work more or less. I am trying to avoid electrical load though.

[8307c4]

ahhh, antabuse for fuelaholics.

You could install a wooden block under your gas pedal so as to prevent it from going past 1/2 way down, then remove those engine performance restrictions and the results ought to be at least as good.

My bmw318is has such a device, thou it's an adjustable bolt you can lower or raise and if you raise it enough it stops the gas pedal from going too far down.
The car came with it, looks factory.
Interesting concept, I thought.

Me, I just lighten the foot, thou I do admit age helps.

[usedgeo]

Originally Posted by 8307c4

ahhh, antabuse for fuelaholics.

You could install a wooden block under your gas pedal so as to prevent it from going past 1/2 way down, then remove those engine performance restrictions and the results ought to be at least as good.

My bmw318is has such a device, thou it's an adjustable bolt you can lower or raise and if you raise it enough it stops the gas pedal from going too far down.
The car came with it, looks factory.
Interesting concept, I thought.

Me, I just lighten the foot, thou I do admit age helps.

Your point is well put but I also think that feeding hot intake air actually affects the efficiency of the engine more than just soft pedaling it.

[Danronian]

I must say that on this tank I just installed the factory warm-air intake back on my VX, and already I notice that it warms up in 2-3 minutes instead of before when it took 5-6. This is a huge difference. I document my MPG, and since this is the only change lately for the car, it should be able to be seen in my gas log as an increase if it does in fact help or not.

[GasSavers_theCase]

Does WAI work?, if so, why?

I'm a bit confused about the idea of WAI (Warm Air Intake), I understand the concept of stoichiometric burn and understand that warmer air temps result in less fuel use, but....consider the following four scenarios;

1. Idling, a WAI engine would use less fuel as the warmer air would result in less fuel needed to achieve a stochiometric ratio, Advantage WAI.
   
2. Acceleration from 0 to 55 mph at a uniform rate. Wouldn't both engines utilize the same amount of fuel with the only difference being the throttle position? No advantage.
   
3. Constant speed (e.g. 65 mph) Again the same idea, to move a given mass at a given speed requires X amount of energy. No advantage.
   
4. Coasting, same as A, advantage WAI.

Assumptions:

• There is no free lunch, the energy needed to move/accelerate a given mass does not change.
• Today's car computers are very efficient in their use of fuel.
• 90 percent (my guess) of fuel use in a car is done with the throttle depressed, coasting/idling does not utilize much gas as a percent of the total.

Other random thoughts:

• Are pumping losses a factor? I understand the rational that a throttle would be opened wider in warm air resulting in less friction, but if one considers the increased frictional losses due to added duct length (to get warm air from around the exhaust manifold), plus the extra weight (another three ounces!) it appears this may balance out.
  
• If WAI worked why don't car manufacturers implement it? It could be as simple as routing the air intake into a shroud behind the radiator and a thermally controlled damper.

I want to believe!, after all I live in a 9000 dd climate and am dreading the inevitable decline in mileage as winter approaches . Anything I can do to gain an advantage is worth considering.

[8307c4]

Originally Posted by usedgeo

Your point is well put but I also think that feeding hot intake air actually affects the efficiency of the engine more than just soft pedaling it.

Understood, but what I suspect did the trick as well is when that corrugated tube was removed it improved air flow. Of course the air is slightly warmer but at anything much over 20 odd mph it makes little difference, there's so much air moving around under the hood anyhow, me thinks it's removing air obstructions that do the trick.

I get my best mpg with the Mr. Gasket high performance air filters, the element is completely exposed and with a 2" high 14" diameter filter it can suck in considerably more air than any factory garbage corrugated tubular contraption can suck in.

Engines still suck air, that air has to come into it some kind of way, take one really good look at any factory intake and it's a wonder air can even get through there... Sure the openings on either end might look nice but I've seen more than a few where at some point or another there is but a 1-2" diameter restriction, and with air it only moves as fast as the most constricted point allows, then just to make matters worse the tube is corrugated...
A tube, to provide optimal air flow needs to be smooth, on the inside!

A high performance air filter fixes that, the hardest part is staying off the throttle.
Not so sure on those new fangled K&N things either, I prefer a more standard method.

My attitude is: Improve air flow and spark and you win, so long you keep your foot off.
> Technically speaking, with even a slight hp increase it should take less throttle, this alone can increase mpg of course.

But increase fuel flow and you lose.

And no, most factory / stock cars are not even close to optimal.

[CoyoteX]

Well I just tried out my old hot air intake again that got worse mileage when I tried it before. This time with the megasquirt I figured I could tune out a lot of the problems with it.

Peak intake temp was 81C 177F IAT takes forever to respond to a change in temp. Took 30 miles for it to get up to temp even though the air filter housing was super hot within 15 minutes. I had to turn the correction speed up for the wideband oxygen sensor to keep it from stumbling all the time. I scaled the entire fuel map 10% lower and pulled 3 degrees of timing out of the entire timing map. The fuel was about right but the timing table was not good. Still had a bit of knock and was not able to get it to go away. I figure the air was hot enough it was not ignition knock but spontaneous combustion so there wasn't much I could do about it.

Filled up before I left this morning and again when I got home and this trip to work was 43mpg compared to the last tank was 58mpg. Around the same temps so it should be comparable mileage.

So I will cut a hole in the hose this weekend and will try and move the temp sensor somewhere better so I can try regulating the temperature to something like 80F and see how that does. I think anything over 100 is going to hurt mileage but I will see if I can regulate the temp a bit better and try getting a gain in mileage. As slow as the sensor reads though I need to get that moved first before I can really tell anything.

Here is a pic of when I put it on the first time:

[Improbcat]

Having gotten my SGII today, did a quick experiment with my xB. I'd pulled the tube that ran from the airbox to behind the left headlight a month back as part of a bunch of MPG improvements. But I was curious how much of an affect on intake temps that actually had (what with all the air blowing through the radiator and straight at the opening in the airbox). So I hooked up the SGII, and set it to display engine temp & intake air temps. Got on the highway and waited for the engine temp to stabilize at 181-182F

On the first run w/o the intake tube at 59-62mph the intake was 69-73F.
On the return run w/o the intake tube at 59-62mph the intake was 73-76F

On the run w/ the intake tube in place at 59-62mph the intake temp was 56-58F.

The difference was so dramatic I cut the second set of runs off short and headed home to take the intake tube off. I was amazed at the difference even at highway speeds.

[boofighter]

on my sunfire i noticed that until the car warmed up it was dumping in a lot of gas. it was as it it was trying to warm the engine up by making it run rich. i took the air temp. sensor out of the air intake and placed it close to the engine block. now the car "thinks" it is warmer then it is. i have seen a bit better mpg.
my theory is that it is now going to run a bit leaner then it was before giving me better millage. i will post a few pictures later to day.