warm air intake is in

[bbanzai]

I believe the physics are sound for WAI or HAI and greater FE. I am not
a gearhead like some of my friends who are serious, very serious performance addicts. Their philosophy has always been greater air density and therefore greater fuel /vol. with all other variables adjusted to encourage and take advantage of this. I have just done a simple one on my 2000 LS2 (V6) Saturn. I bought this for a song and it is my testbed. Driving
this through the fall and winter using fairly aggressive techniques would only give me 27.1 mpg at best. I am on my second fill with the WAI and I am doing better that the 31.2 mpg combined from the first fill. I will soon install
a dash mounted "modified" stick thermometer in the box to "locate" the optimal temp. I have to agree with RIDE. I think there may be advantages and disadvantages to the radiator vs manifold question of from where to draw the air. I have a flex exhaust going from my air box to above the manifold with a shroud for the present. I was also thinking of shunting coolant to copper wrapped around the flex exhaust. But, this is a bit of work and unless you get adequate heat transfer it may not be worth it. As a newbie here I am finding all of this very useful and fascinating.

John

Red Green, "If the women don't find you handsome, they should at least find you handy."


Red Gree

[GasSavers_BEEF]

bbanzai,

instead of a temperature sensor, how about a scangauge. it will show you your IAT intake air temperature and your MPG along with a lot of other stuff. It is a little on the pricey side but installation is a breeze.

I have mine set up to show MPG (instantaneous and trip), water temp (coolant) and IAT (intake air temp) this way I can monitor the air temp to make sure it gets high enough (130+ seems to do well and the higher the better at least to 155, highest I have been) and still monitor my water temp to make sure the engine doesn't overheat.

you could also look into a grill block (if you haven't already). it helps with aerodynamics and helps the engine heat up faster. some will say that you need the airflow and you do need some airflow but the concept is that most cars are made to run in all environments from the very hot to the very cold and most of us live somewhere in the middle. because of this, you don't need the massive grill area that the manufacturers are giving you to adequately cool your engine. that being said, I wouldn't even attempt it without some sort of gauge to measure your coolant temp. the cheesy inside gauge in the cluster is inaccurate and very slow to react so I don't consider it a good enough gauge.

oh and welcome to the site.

[R.I.D.E.]

My car is a 94. I wish I could use a scan guage, but sadly it's OBDI. WAI has been around at least since the Flathead Ford V8 in 1932. In the carburetor days without WAI you had carb icing which means the venturi effect in the carburetor cooled the air fuel mix which prevented good atomization of the mixture.

The last days of the carb era they drew air off the mainfold to preheat it. When you checked the system you simply placed your hand on the air cleaner to see if it was hot. The control was a heated bimetallic spring that opened the flap depending on the ambient temperature. It was a hands off system that required no real maintenance.

When fuel injection came along (remember the diesel has been fuel injected at least 100 years) the fuel injector needed no venturi to promote atomization. The manufactureres knew you got more power without heating up the air, so they did away with WAI. Denser air means more compression and more power.

The difference between air density between 32 degrees and 200 degrees is 20%. This reduces the maximum power of your engine in the summer, but it also increase the efficiency. The heat content of the air in summer reduces its density. Your fuel is warmer in the summer so it will atomize better.

If you want power you want cold air and fuel, if you want economy you want hot air and fuel.

You are trading maximum power for maximum economy. There is no reason it will not work on any car, as long as you understand you will not have the same maximum power.

We use the term "pumping losses" as a trash can to throw in all sources of inefficiency. It's far more complicated than the energy required to move air through an engine. Lets not debate that in this thread, but rest assured the lower the density of the air you are moving the less work it takes. That's easy to understand.

Basically a warm air system preheats the incoming air above its normal temperature. I think BEEF has it right 155 is about the design limit for the FI system. when the air has less density the ECU gives it less fuel to maintain the same mixture. 10% less dense air with 10% less fuel with a higher heat content per unit of mass means the fuel mixture will be more homogenous.

When a fuel injector sprays out fuel it naturally cools off because the surface area of the fuel particles has increased maybe a hundred times its liquid state. The temperature of the air the fuel is injected into will help atomization if it is hot, and hinder atomization if its cold. Since WAI uses heat energy that is normally wasted you are collecting free energy and making your system more efficient.

Its important to understand when you recover wasted energy you are improving the overall efficiency. That does not consider the fact that you are not only recovering that energy you are using it to improve your engines efficiency which makes the overall effect even more significant. Reutilization is more significant that just saving.

It seems like people are worried about overheating. Consider the Phoenix Arizona temps which can approach 140 degrees. Your car is designed to operate in those conditions. All systems must function properly even the cooling system when it only has a 40 degree differential between the outside air temp and your 180 degree cooling temp.

Ideally you would want to minimize the thermostats restriction on the water pumps work to push coolant through your radiator. WAI will not make your engine overheat unless there is another problem like a partially plugged radiator. In cars with thermostatically controlled electric fans the fan might run more especially if you have blocked airflow to the radiator.

The cooling system has a condsiderable reserve capacity so your engine doesn't melt if you drive in areas like Phoenix regardless of where you live or the highest air temps in your area.

Sustained high speeds also increase the load on your cooling system. A radiator gradually looses its reserve capacity over time. A ten year old radiator may have lost 50% of its reserve capacity. You never notice it because the thermostat opens more to compensate for what is essentialy a smaller radiator. Eventually your car runs hot at high speeds. As the radiator capacity becomes less and less the threshold of overheating becomes lower and lower, while the thermostat opening increases until it has reached its limit.

At this point if you removed the thermostat the engine would run at the same temp, when normally it would run much cooler.

I know this explanation is long, and a significant number of members already know all this. The other side of the coin is those that do not know this need to understand the principles of operation, instead of being scared of a modification that could only create a problem if there are other issues.

You dont make a man with 90% blocked arteries run hundred yard dashes, just as your dont want to surpass the capacity of your cooling system in its present condition.

I run my WAI year around, even though ambient temps here can exceed 100 degrees. The top of the radiator will always be around 180 degrees once your car has warmed up regardless of outside temps. My car also has a 65% grille block from the factory, and I will leave that in place.

So far I have seen no increase in coolant temps. I have noticed less power and I would bet the maximum power is also significantly lower (maybe 10%).
This is the tradeoff I am more than willing to accept, especially considering the 57 MPG average for the last 2300 miles in the only car I drive under all circumstances.

Now this is important. My car is a time capsule. A 1994 with 31.5 k miles that was stored inside for 13 years. The tires are 15 years old and are still OK. I have never changed the timing belt. The paint is not faded. These are indications of it being in a controlled environment (inside regulated temps and humidity, no direct sunlight) The interior is perfect.

I dont have to worry about the radiator capacity, which is not to say your radiator capacity could be compromized.

I can't tell you the exact amount of improvement, but I can tell you that its significant and it will be more significant in winter. The colder your average temperatures the greater the significance. My car has been on the road less than 2 months, it was totalled in 1995.

In my 1994 Civic I simply reversed the intake snorkel and trimmed enough off the horn so it wasn't rubbing on the top hose. Its about 1/2 inch from the hose. Cost me nothing, and also helps to speed up engine warm up in cold weather. My engine reaches normal operating temp in just over 1 mile now.

Without WAI my previous car a 1994 DeL Sol took over 4 miles to warm up when I was P&G and almost 3 if I did not P&G. When I blocked the grille completely that dropped 50%.

Just my personal experience, you should consider all the variables specific to your vehicle and also monitor coolant temps carefully. WAI should not make your car overheat. If it does your radiator is probably in need of service.

If I lived in Phoenix, I might consider disconnecting the WAI and the grille block when temps soared. Its not easy for a cooling system to frunction properly when the ambient temp is just slightly more than 40 degrees lower than the cooling system operating temp.

Consider running a hotter thermostat if you are sure it will not create problems. I do not want to change mine because I can't be sure a 195 stat will not give me a problem long term. I want this car to last another 200k miles, your situation may be different.

The only other mod to my car is tire pressure. Remember these are 15 year old tires. There is no way I will inflate them to much more than their 35 PSI rating. Currently they are at 39 PSI. I will see if there is a significant difference compared to their previous 34. I had inflated them to 36 and over 6weeks that pressure dropped to 34 on every tire, so I don't have any significant leaks.


regards
gary

[GasSavers_BEEF]

another update: I finally got higher temps on the intake (current high temp is now 179) considered taking out part of my grill block but engine temps are still under 200 when driving. stopped at stoplights may see 210 or so. we have also seen our first 100 deg day around here so I feel pretty good about it.

my gas log is showing a better average of 35+ for the last couple of tanks. I tried my hand at PandG (engine on). seemed to be more trouble than it was worth so I stopped doing it. it also threw my scangauge way off. my best tank so far has been without PandG.

now if I can just get those first two tanks off of me (baselines) then my average will look better. dang this averaging.

*edit* also, I have a friend that lives with me and he finally put a front seat in his car so we are ACTUALLY carpooling. (he used to just spot me for gas) so my gas log entries will be more spaced out. works good for both of us.

[theholycow]

P&G can be a lot of work. It takes some practice to know when to do it and when not to, and how to do it well. It surely also depends on traffic conditions and your specific roads, and your car.

It wasn't going to work for me until I realized that, just because I'm doing it, doesn't mean I need to do it ALL the time. Once that occured to me it became easier and more worthwhile.

[Roadking41a]

I have been reading here with great interest will the hot air intake work just as well with a carb engine?

[Project84]

will probably work better.

I bought a sheet of galvanized steel last night that's intended for HVAC work, but instead I made a cardboard template and cut the sheet to my liking to create my exhaust shield... the only thing left to do is fab something to collect the air from behind the manifold and stuff it into the airbox.

HAI HERE I COME!!

[Roadking41a]

I have the factory breather and another that I picked up for free. I was planning on making a dual snorkel breather out of it which would be easier to get hot air off the exhaust manifolds on both sides. Is that a good Idea?

[theholycow]

I imagine with a carburetor it would be bad. It would vaporize the fuel easier, bringing more fuel in, and also there would be less mass of air but the fuel wouldn't be adjusted for it like it is in a fuel injected engine.

I'd love to find out from experimentation rather than this theorizing, though.

[Roadking41a]

My car is a 86 GM and has the electronic carb and dist thats controlled by one of the first ecm GM came out with so it's not jetted like a regular Q-Jet. It can't hurt the only thing I have to lose is a few dollars,I think it is worth a try.I know most everyone here has newer cars and trucks.If this works then I can use it on my 85 F150 with EFI.