How many of you are running hot air intakes?
 

So far I removed the tubing so Im sure its sucking in hot air now, I heard hot air reduces the power but helps fuel economy. Im just going to remove the lid all together I think. Your thoughts on sucking in hot air?

https://www.fuelly.com/attachments/fo...cd8fde8bf7.jpg

Given the lower MPG i just saw yesterday with rain and a 20 deg lower IAT, I think that the warm air is better for FE. Hard to say for sure, because I was dealing with heavy rains at times too, but the IAT was much lower on the trip were 23.3mpg was had, rather than the previous 26.6 on a sunny day with higher IAT.

I run full hot air in winter only...then I think it helps some.

Three6Eight -

This would have made a great poll. I am running an HAI. Different drivetrains will have different responses. It has worked for almost all the Saturn S-Series owners (thanks cheapybob!).

CarloSW2

Rain really eats into FE so its going to be hard to get a good feel for the 20deg change alone. For me I've seen 3-8mpg loss on heavy rain trips.

I may be seeing an affect from the recent cooler air intake temperatures as well. Although I suspect its something else thats being affected by the 30deg lower temps besides intake air.

I'm running the HAI. Saturns like it. I'd say that other GM cars would also. It uses MAP sensor in stead of MAF. My little brother tried the HAI in his nissan altima. It would do well at first and then the ECU would adjust for the hot air and the mileage would stay the same.

I have used hot air before with fairly good results (saturn), but I think it has the best results in the winter.

Today I did a little test, with the intake hose and lid on driving steady state 55mph the intake temperature was at 31 degrees C. Taking those off and driving for 10 min to get it stable it was reporting 32 degrees C. So on a Metro there isn't much difference in running the stock hose and lid and not running it. There just isn't much heat under the hood normally so it is still getting colder air.

I might try hooking my warm air setup back on there adjusting it trying to get a good temperature going into the intake but I have no idea what ideal air temperature should be. When I was running straight into the mainfold it killed my mileage so I know having it super hot is no good.

Hey man so your the guy who owns that Metro Page. When I got mines its one of the first sites I ran into.

What spark plugs would you reccomend for this car? Wires? Today I was driving and my car felt like it had 10 horsepower and it was idling bad I thought it was ready to hit its death bed :( I popped the hood and a spark plug wired just disconnected and I put it back on, its on there loose though so Im gonna replace them

I tried joining the swift page I actually tried twice and twice they rejected me. Bunch of elitists or what?

Nice stable you there dude. You got the Z28 and the Metro for the days you wanna save gas. Cool combo :cool:

On my VX i have a short-ram intake, which in affect is a HAI. I haven't been able to get my old EPA on my car yet so I'm not sure if it really makes a difference.

That being said, this intake is a lot larger than the factory one, and it has a diry k&n filter on the end...so probably not a good comparison

teamswift might have some email issues or something I will message the guy and let him know about it.

I used the Bosch +4 plugs cause I am lazy and don't like having to change them often. Wires I use whatever is cheapest since they really don't matter much on these cars. Distributor cap and rotor might be worth looking at as well to make sure the electrodes are in good shape.

I will probably be experimenting with a warm air intake again now that I can measure the IAT sensor easily. It seems like shoot for 80F temperatures in the intake is ideal. So if I get that figured out it might be worth trying on other Metros but running it really hot just kills the mileage. Mine dropped 8mpg from running a hot intake when I tried it last year.

Hot Air
 

My intake draws "warm air" -- with a target of about 100F. It requires re-direction in the Summer and Winter (exhaust manifold area in the Winter, and as ambient outside air as possible in the Summer).

Each application is different -- in my case too hot is detrimental (130+) or too cold (<70F).

Considerable gains are met if I keep it above 70F in the Winter. Otherwise, modest FE increases result any other time the year.

RH77

I did an a-b-a test today with HAI... same test route as always, 45/55 mph bypass with stoplights out, 65 mph interstate out, 65 mph interstate back, 45/55 bypass back.

a - 22.3 / 20.4 / 19.4 / 22.2 IAT 78 / 80 / 88 / 90

b - 21.5 / 21.5 / 20.5 / 21.5 IAT 114 / 121 / 127 / 122

a - 22.0 / 20.6 / 20.1 / 21.9 IAT 80 / 82 / 89 / 91

no difference really. So, I went from 25.5 to 22 just with a change in the weather... sigh, and IAT back to hotter temps didnt do anything for me. No rain today.

Gonna remove the side mirrors next

Bummer -- I haven't heard of Fords reacting to temps yet.

Regarding the mirrors, are you planning a fish-eye internal mirror, cool cameras, etc???

RH77

If you're seeing better mpg when your car has less power then you likely have a heavy throttle foot. Lighten that, then restore the car's power and lighten up the foot some more, now you'll see some mpg.

However, if you continue to see marginal numbers then it is quite possible your best fuel economy method is to not drive the car, at least in my case this always saves the most.

Better mpg or less gallons burned, you decide which is best.

My 87 civic (with carb) has a stock system that keeps the intake air around 100 degrees.

I am.

I use a TRD drop in air-filter, took out my snorkle, and its helped me average about 2.5-3 more mpg , in my 1.5L engine.

I have an HAI. In fact, I should be receiving my high-temperature silicone adhesive backed PTFE insulating tape from McMaster-Carr today. I am going to wrap the intake snorkel and the tube I have going from the intake resonator hole in the airbox to under the exhaust manifold. In the cooler weather I am topping out at 100 &#176;F intake air temp and I want to pump it up.

Hot air box
 

I would like to use a small heater core and make a water to air intake air heater box. Has anyone here done that? I think the most likely heater core would be from a chevy chevette but there are probably many possibilities. I am not getting very hot air in the winter now.

When I used to be in regular contact with Fran at hydrogen-boost.com it seems to me that he tried something like that in his Saturn SL1. I think you would want a way to control the heat because I think that too hot(especially on a Saturn)can cause the timing to retard which ends up killing your FE. I'm not sure, but it seems like maybe 150F was the upper limit?

I just started running an HAI on the Prius last weekend so I don't have much data but it seems to be helping.

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.

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.

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.

I want to believe!
 

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.

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.

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 :eek: 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:
https://www.gassavers.org/attachment....1&d=1197002017

https://www.gassavers.org/attachment....1&d=1197002203

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.

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.

anyone here use the resistor on the iat sensor wiring? I have mine (96 saturn)reading 224*f.

Warm air intake? I have a naked air filter sitting on top of the carb. That probably does the trick.

I am not running a modified intake - not completely sold on the idea yet.

I ran one on my R-18 Civic and run one right now on my 2.3 Mazda3. I have also ran them in the past on American iron V8's.

I much rather see 70f intake air temp when it is 30f. Than 30f intake air temps.