Wanting to Confirm/Bust the HAI - Gas Savers

rh77 · 10-01-2006, 09:50 PM

So, I've been fooling with this Hot Air Intake for a long time now and I just don't know how to quantify it into some data that will confirm or bust the mod. In addition to the ScanGauge, I have a data logger (Davis CarChip E/X) that uploads into the computer, and graphs display results. I've always noticed that the hotter the air, the lower the "Fuel Trim", meaning it's running leaner.

So, is there another variable I should check to confirm or bust it? The logger collects: Vehicle Speed

Engine Speed

Throttle Position

Coolant Temperature

Engine Load

Intake Manifold Pressure

Air Flow Rate

Intake Air Temperature

Timing Advance

Short Term Fuel Trim

Long Term Fuel Trim

O2 Sensor Voltage, and

Battery Voltage

Which of these data points can be collected to help with this? Speed is automatically collected, plus you can selected up to 4 more variables. I tried it tonight, but I couldn't get the air cold enough -- more tinkering is needed.

RH77

onegammyleg · 10-02-2006, 01:10 AM

Hi rh77 -?In addition to the ScanGauge, I have a data logger?

Your in a prety good situation to do this sort of experiment as you can see more information as to whats going on.

What ide try is this.

Measure the intake temp and the fuel trim with the hot air intake on and see what the resistance of the air temp sensor is reading.
If the logger doesnt give this exact OHM figure you might need to measure this manually with a high imperdance digital multimeter as you drive.

Then , take off the warm intake and alter (with resistors) the signal on the intake temp sensor to match what it read when the hot intake was fitted.
This will simulate the temp sensors hot air reading.

Then drive again and note the mixture readings.

?If you do this rite? , it will confirm if the hot air has just altered the signal from the intake sensor and the computer has given the correct mix to suit or if something else is going on.

Problem is tho , that you will be telling the computer that it should give less fuel based on what the temp sensor is saying because hotter air is thinner air and thinner air is less air.
To keep the correct mix with less air the computer should give less fuel.
BUT..
When you do this test you will in fact be drawing in cold air (more air) and the O2 sensor will see a very lean mixture.
So it will probably self adjust and add more fuel.

Because of this it will probably show better FE with the hot air intake air intake., but really all this interaction wil make the result inconclusive.

PS , I believe that the hot air intake mod does work , but a similar result can be got from altering the intake sensors output by a SMALL amount.

rh77 · 10-02-2006, 08:31 AM

Quote:

Originally Posted by onegammyleg

?If you do this rite? , it will confirm if the hot air has just altered the signal from the intake sensor and the computer has given the correct mix to suit or if something else is going on.

Problem is tho , that you will be telling the computer that it should give less fuel based on what the temp sensor is saying because hotter air is thinner air and thinner air is less air.

We've found that this works for some models, especially some Saturns. I don't like to "trick" the ECU into thinking that it has leaner air, otherwise I might get some nasty detonation in the lean-burning conditions. I do have to use at least 91 octane with the HAI, or else I get ping under load. The other question is: will the investment of premium fuel offset the FE and/or emissions to be worthy?

Good thoughts tho...

RH77

omgwtfbyobbq · 10-02-2006, 01:37 PM

I'm gonna go with probably because the difference between 89 and 91 is ~4-5%, little less actually. I've seen a poster on the cmpg forums claim that the IAT resistor dropped the fuel consumption at idle in half, and lowered the consumption cruising at 35mph by a significant amount as well. If gas was $1 a gallon, probably not, but now, if the IAT mod nets a +5mpg increase while still allowing you to drive normally, then the ~10+% increase in FE is worth the 3-4% increase in price.

rh77 · 10-02-2006, 02:04 PM

Quote:

Originally Posted by omgwtfbyobbq

I'm gonna go with probably because the difference between 89 and 91 is ~4-5%, little less actually. I've seen a poster on the cmpg forums claim that the IAT resistor dropped the fuel consumption at idle in half, and lowered the consumption cruising at 35mph by a significant amount as well. If gas was $1 a gallon, probably not, but now, if the IAT mod nets a +5mpg increase while still allowing you to drive normally, then the ~10+% increase in FE is worth the 3-4% increase in price.

I figured that the Premium wasn't costing me any more, but I am hopefully emitting less -- which is one of my GS Goals.

Someone suggested to me to compare the ignition timing vs. the fuel trim to see if that would effect it.

Before I bought the ScanGuage, I had this OBD-II logger. So last Winter I noticed every time that when my half-arse HAI came loose and cold air was introduced, the trim would go up into "richer" territory. The problem is that now, even at night it's not getting cold enough to test -- I'm still about 40-degrees over ambient. My airbox is a tad screwed-up, I will admit. I'll need to go in there and seal some things up and try it again.

The problem is, I can't monitor the ScanGauge and log data at the same time -- same port -- so I'm flying blind after I hook up the logger. I'll tinker tonight, and run some more tests.

Any requests on the variables tested? Clearly IAT, Fuel Trim, and what else -- 2 more variables can be added from the list.

omgwtfbyobbq · 10-02-2006, 02:49 PM

Manifold temperature. That plus IAT should give you a ballpark for volume. In terms of emissions, by increasing efficiency you're definitely lowering carbon dioxide emmited, but otoh, if running lean, NOx emissions spike, so you're possibly helping more on the macro scale (reducing GHGs), but maybe emitting more on the micro scale (local pollution).
There seems to be two ways around the whole IAT deal...
-Fooling the IAT sensor by putting a resistor in, car runs lean/retards timing.
-Actually routing warmer air into the intake.
-Combo of both.

Ideally, if the air is just warmed, there shouldn't be pinging, because the ECU will retard timing/ reduce fueling so that normal combustion happens, but this is the purpose of the EGR, so it probably wouldn't show much benefit. If the car is running leaner via IAT resistor, or the ECU not being about to keep up with the hotter air, then GHG emissions drop even more, but NOx emissions/pinging increase. So... it's a trade off?

What you should do is what MetroMPG did and do a couple bidirection runs with a WAI and a CAI. His car didn't seem to respond because most cars with an EGR system will have it on during cruising and any change in IAT is minimal compared to the increased heat from the exhaust via the EGR system. I suppose the best wa would be to fiddle with the EGR system, but that would probably require SAFI as well. Actually, iirc the EPA tested a turbocharged SI engine with high rates of EGR and found better efficiency than the current TDIs exhibit, with much lower emissions levels. Hmm.. sounds like a really cool project. Buy a spare engine, turbo, wideband oxyen sensor, and megasquirt or whatever, then tune it with high EGR until fuel consumption at various loads, probably emphasize 1.5-3k rpm, is minimized, then drop it in your car and see what your mpg is.

zpiloto · 10-02-2006, 03:36 PM

I found that there is a sweet spot so to speak with the WAI on my car of about 120 IAT. Above that the timing starts to get retarded and the FE goes down. Running a higher octane did help with the max temp I could run before the timing would start to retard but the increase in temp did not relate to an increase in FE. I try to keep it between 110-125. With the belly pan I have to remove the WAI if the temps are going to be above 90 because the IAT gets to warm. I just installed it again now that the temps have dropped.

rh77 · 10-02-2006, 10:21 PM

OK, I went out tonight and tried like crazy to get some cool temps into the intake. I can't consider it as a conclusion, but it's taken some wind out of the 'ol sails...

I crunched the numbers manually because the dumb program has no "export" function...

Conditions:

*Same driving loop of approximately 10 miles
*Acceleration was consistent at 25% throttle up to 55 mph, upon which the cruise control was engaged.
*Variable mismatch: the hood was unlatched to allow for the modified intake (to the first safety latch so the hood wouldn't fly up, Tommy Boy style -- which had to have created additional drag).

*
Test A: High Intake Air
Intake Air Temp Average: 125.9F
Ignition timing Average: 24.3
Fuel Trim Avg: -5.75%
FE: 27.3 MPG

*
Test B: Lower Air Temps (still too hot out, but...)

Intake Air Temp Average: 108.4F
Ignition timing Average: 29.6
Fuel Trim Avg: -4.69 %
FE: 33.6 MPG

Now what do you make of this??? There has to be a "sweet spot" because super-low temps would, hypothetically, kill trim and FE.

Conclusion: On this test, ignition timing retarded considerably with a negative effect on FE, as IAT was increased.

RH77
???????

zpiloto · 10-03-2006, 11:16 AM

Quote:

Originally Posted by rh77

OK, I went out tonight and tried like crazy to get some cool temps into the intake. I can't consider it as a conclusion, but it's taken some wind out of the 'ol sails...

I crunched the numbers manually because the dumb program has no "export" function...

Conditions:

*Same driving loop of approximately 10 miles
*Acceleration was consistent at 25% throttle up to 55 mph, upon which the cruise control was engaged.
*Variable mismatch: the hood was unlatched to allow for the modified intake (to the first safety latch so the hood wouldn't fly up, Tommy Boy style -- which had to have created additional drag).

*
Test A: High Intake Air
Intake Air Temp Average: 125.9F
Ignition timing Average: 24.3
Fuel Trim Avg: -5.75%
FE: 27.3 MPG

*
Test B: Lower Air Temps (still too hot out, but...)

Intake Air Temp Average: 108.4F
Ignition timing Average: 29.6
Fuel Trim Avg: -4.69 %
FE: 33.6 MPG

Now what do you make of this??? There has to be a "sweet spot" because super-low temps would, hypothetically, kill trim and FE.

Conclusion: On this test, ignition timing retarded considerably with a negative effect on FE, as IAT was increased.

RH77
???????

Mine acted the same way when the IAT gets up around 130 or higher the FE drops like a rock.
I think with the temps the way they are you need to try again without the WAI because you already have it. Here's a couple of things you can try that I used for my commute during the summer to keep the IAT in my sweet spot. My airbox is set up so that the filter sits on top and there a a huge space under it that I put 3 glasses of ice in. This would last 30 minutes at 100+ for the commute. I quickly got tired of that. So I tried a wet sponge down there and that would last about 1.0. and keep the IAT under 125. The wet sponge acutally keep it the same IAT as the ice as long as the car was not idling. But now you added increased humidity to your equation

The spong did the trick and keep the temps low enough that the timing was not retared. YMMV

psyshack · 10-03-2006, 12:11 PM

I have found with my Civic if the air is to warm it hurts its mpg. I was running about 119f air intake yesterday on I-40 and struggling to keep 50 mpg. I stoped and sliped the stock tube back on the air box to use the OEM intake system. Air temps droped to 96f and mpg game up to 54 mpg.

We are having temps during the day in the low to mid 90's right now in Okiehoma. I will pull the intake tube off when temps drop back down to the high 40's and 50's here in a week or so.

My gut is telling me. My Civic dosent like intake air temps above 105f nor below 60f.

This past summer with air temps at 100f to 105f it seemed to have trouble with getting good mpg. With saturation of the intake system in OEM config good mpg was hard to get.

LxMike · 10-03-2006, 05:41 PM

my one and only w.a.i experiment i cute short cause colants temp got too highmy car had an air silencer underneath the air box so i took that off, and used a shop vac hose from near the exhasut manifold. intake air temps was up about 10 degrees or so but coolant temp was up 20-25! usual run 181-185 and was up to 211-215. air temps here are still close to 90 during the day so maybe this is more suited to cooler weather or maybe i need to do a lil more testing.

rh77 · 10-03-2006, 05:57 PM

Quote:

Originally Posted by zpiloto

Mine acted the same way when the IAT gets up around 130 or higher the FE drops like a rock.
I think with the temps the way they are you need to try again without the WAI because you already have it. Here's a couple of things you can try that I used for my commute during the summer to keep the IAT in my sweet spot. My airbox is set up so that the filter sits on top and there a a huge space under it that I put 3 glasses of ice in. This would last 30 minutes at 100+ for the commute. I quickly got tired of that. So I tried a wet sponge down there and that would last about 1.0. and keep the IAT under 125. The wet sponge acutally keep it the same IAT as the ice as long as the car was not idling. But now you added increased humidity to your equation

The spong did the trick and keep the temps low enough that the timing was not retared. YMMV

The highest I've ever seen the IAT was 212F, which was about 110 above ambient at the time. The car drove, no problems (that's with premium fuel, otherwise I'd detonate the B18 into the next county-- I can't confirm FE, tho.

Z- That's actually fascinating that you did this experiment (is it posted?) I just need to know the bell-curve of temp for my model (prob. experimentation). Now regarding humidity, the concensus is: the higher, the better (denser air = better combustion). I may try a sponge at the bottom of the airbox under the cone filter and a tube with a funnel quick-connect to easily add water to moisten the sponge without popping the hood -- to test it out. I'm bored, so I'm off to the hardware store...

RH77

zpiloto · 10-03-2006, 07:16 PM

Quote:

Originally Posted by rh77

The highest I've ever seen the IAT was 212F, which was about 110 above ambient at the time. The car drove, no problems (that's with premium fuel, otherwise I'd detonate the B18 into the next county-- I can't confirm FE, tho.

Z- That's actually fascinating that you did this experiment (is it posted?) I just need to know the bell-curve of temp for my model (prob. experimentation). Now regarding humidity, the concensus is: the higher, the better (denser air = better combustion). I may try a sponge at the bottom of the airbox under the cone filter and a tube with a funnel quick-connect to easily add water to moisten the sponge without popping the hood -- to test it out. I'm bored, so I'm off to the hardware store...

RH77

No testing data. My objective was to bring the IAT down. I ran it for 2 months and it worked well. Guessing I has a 8"x4"x3/4" sponge that I roll up so it would fit inside a 2.25" diameter hole with cord on it. I would soak it, put it in the intake to the back of the box and when I need to soak it again I just used the cord to pull it out. It would bring the temps down around 25 degrees or so. Hope it works for ya.

rh77 · 10-03-2006, 07:55 PM

Quote:

Originally Posted by zpiloto

No testing data. My objective was to bring the IAT down. I ran it for 2 months and it worked well. Guessing I has a 8"x4"x3/4" sponge that I roll up so it would fit inside a 2.25" diameter hole with cord on it. I would soak it, put it in the intake to the back of the box and when I need to soak it again I just used the cord to pull it out. It would bring the temps down around 25 degrees or so. Hope it works for ya.

Well, I've got the sponge to test for tomorrow (where was that guy from the movie "Fever Pitch" that gave away sponges when I needed him)? Anyways, the plan is to place it flat inside the airbox, presoaked for the first long trip. If it works, then a tube will probably be inserted for EZ moisturizing. Heck, I might be able to collect rainwater and make it enviro-friendly

A concern: I have the K&N, cone filter that is coated with special oil on a regular basis to allow it to function as intended. The moisture may wash-away the oil and up the intake, gunking up the works, and requiring more maint. to the filter.

RH77
"2005-2006 Grand Champion, Family Fantasy Baseball League"
Mighty Muskies: Go, fight, SWIM!

rh77 · 10-04-2006, 09:34 AM

Well Z, the wet sponge worked like a charm! The IAT ranged from 92-126. Since it was all city driving, that number would have stayed around 115, as that was the average temp noted when throttle was applied and more air was drawn over the sponge to cool the air. No sponge yesterday saw temps of 110-150 on the same route and temps!

After a week of testing, I'll open up everything from the throttle out to the airbox to see if there was any filter oil bleed or water getting into the intake. I doubt the latter, as the car didn't hesistate like it was trying to compress water.

Great idea, and thanks!

RH77

red91sit · 10-09-2006, 07:49 PM

I see the topic is mostly concluded, i would like to add a bit of information i stumbeld upon today...

i was lookign at a stock B-16a2 ECU's rom and noticed the fuel multipliers,

In Farenhiet degres, and in mutliplication factor of the standard value,

12.2 - 1.21 -- 21% more fuel
16.7 - 1.21
22.5 - 1.13
39.6 - 1.06
70.0 - 1.00
145.9 - .94
212.0 - .94

According to this, we should not see much improvement from the higher temperatures. Since this is not true OBD2 must be a lot different, or the o2 sensor and knock sensor are having a lot to play with things?

rh77 · 10-09-2006, 08:04 PM

Quote:

Originally Posted by red91sit

I see the topic is mostly concluded, i would like to add a bit of information i stumbeld upon today...

This data is exactly what I needed. Anything close to routine outside temperatures seem to be the benchmark 70F (+60/-30). Too cold and it runs rich (introduce heat in the Winter), and way hot only yields 6% savings -- but with that savings in OBD-II, less power, and reduced timing is expected. So the sweet spot seems to be 50-130?

Now then, would the coldest temp before it switches multipliers be the most efficient temp (like 40-45F?) for power, timing, etc?

RH77

edited for benchmark interp.

red91sit · 10-09-2006, 08:27 PM

Quote:

Originally Posted by rh77

This data is exactly what I needed. Anything close to routine outside temperatures seem to be the benchmark 70F (+60/-30). Too cold and it runs rich (introduce heat in the Winter), and way hot only yields 6% savings -- but with that savings in OBD-II, less power, and reduced timing is expected. So the sweet spot seems to be 50-130?

Now then, would the coldest temp before it switches multipliers be the most efficient temp (like 40-45F?) for power, timing, etc?

RH77

edited for benchmark interp.

Well, your specific example is extra tricky, i looked up the maps for the teggy, (the test vehicel for this study correct?)

At low loads, the car doesnt' lean out at High IAT's, but at High load, it leans out a bit more :S, and for low loads, it uses a little more for cold temps, and, a bit more for cold temps at high load,

Soo, at cold temps, you should get better gas mileage if you run under low load, and at high temps, you shoudl get better gas mileage at high load haha. oh my

rh77 · 10-09-2006, 08:39 PM

Quote:

Originally Posted by red91sit

Well, your specific example is extra tricky, i looked up the maps for the teggy, (the test vehicel for this study correct?)

At low loads, the car doesnt' lean out at High IAT's, but at High load, it leans out a bit more :S, and for low loads, it uses a little more for cold temps, and, a bit more for cold temps at high load,

Soo, at cold temps, you should get better gas mileage if you run under low load, and at high temps, you shoudl get better gas mileage at high load haha. oh my

Yup it's for the 'Teg. Soooo, what the crap do I do?

Is the difference in leaning-out large enough to design a plumbing system that draws hot air at high loads and cold air at low? Instead of a complicated load-based switch, would vacuum roughly equate load? If so, a vacuum valve would be much easier to locate. Also, what's your source of mapping?

RH77

DRW · 10-09-2006, 10:56 PM

Thanks for the peek inside a Honda ecu, red91sit. The temperature compensation seems similar to the map used in the Mitsubishi ecu in my car.

The Mitsu ecu shows the temperature compensation extrapolates between values. For example, if the fuel adjustment map uses 1.06 at 39.6 degrees, and 1.00 at 70 degrees, the ecu would extrapolate a correction factor of 1.03 at 55 degrees. There wouldn't be any steps or switchpoints.

I'm assuming the Honda ecu would work the same way.
I'd also assume the temp comp map matches the adjustment needed to keep the fuel trims near 100% as temp changes, since air density changes with temp. It would help the ecu keep track of the actual ammount of air flowing into the engine so it didn't have to rely on fuel trims to take up the difference.

red91sit · 10-10-2006, 03:37 PM

Quote:

Originally Posted by DRW

Thanks for the peek inside a Honda ecu, red91sit. The temperature compensation seems similar to the map used in the Mitsubishi ecu in my car.

The Mitsu ecu shows the temperature compensation extrapolates between values. For example, if the fuel adjustment map uses 1.06 at 39.6 degrees, and 1.00 at 70 degrees, the ecu would extrapolate a correction factor of 1.03 at 55 degrees. There wouldn't be any steps or switchpoints.

I'm assuming the Honda ecu would work the same way.
I'd also assume the temp comp map matches the adjustment needed to keep the fuel trims near 100% as temp changes, since air density changes with temp. It would help the ecu keep track of the actual ammount of air flowing into the engine so it didn't have to rely on fuel trims to take up the difference.

Yes, honda also extrapolates for all of their maps. My source of htis information is a stock Honda Bin from a 1997 Integra. I use "Chrome" to explore these, and to tune my Turbocharged B-16a2 coupe

rh77

The difference between AIT adjustments for high load and low load is minnimal, really not worth spending more time looking into. I'm much more interested in getting warm air to the intake in winter. Warming up the car as fast as possible is also highly desireable.

JanGeo · 10-10-2006, 04:30 PM

Actually you want colder air at high loads so you don't get knocking and you would get this if you had a limited heating intake that would warm air traveling through it less if moving quickly and heat it more if the air was moving slowly.

rh77 · 10-10-2006, 04:43 PM

Quote:

Originally Posted by JanGeo

Actually you want colder air at high loads so you don't get knocking and you would get this if you had a limited heating intake that would warm air traveling through it less if moving quickly and heat it more if the air was moving slowly.

I have an Engine Block Heater, but no where to plug in when I park at the airport. Currently, the air is being draw from the engine compartment. When it gets super-cold, I may have to implement the HAI/WAI to keep the temps stable.

RH77

JanGeo · 10-10-2006, 05:28 PM

I got an idea - maybe you should start the engine up to warm it up . . . no wait that's how it is supposed to work. You need a source of energy . . . park in the sun with a solar heater tank inside the car and use the heated coolant to preheat the engine air and engine for that matter. I always thought taking the air from inside the car cabin would be good for forced air flow then I realized how much air the engine takes . . . could suck the roof in if you didn't have a window open or suck exhost back into the car too.

Anyone think about insulating the entire engine since the radiator cools most of the engine if it was closed up and insulated really well it would stay warmer a lot longer.

rh77 · 10-10-2006, 08:48 PM

Quote:

Originally Posted by JanGeo

I got an idea - maybe you should start the engine up to warm it up . . . no wait that's how it is supposed to work. You need a source of energy . . . park in the sun with a solar heater tank inside the car and use the heated coolant to preheat the engine air and engine for that matter. I always thought taking the air from inside the car cabin would be good for forced air flow then I realized how much air the engine takes . . . could suck the roof in if you didn't have a window open or suck exhost back into the car too.

Anyone think about insulating the entire engine since the radiator cools most of the engine if it was closed up and insulated really well it would stay warmer a lot longer.

A while back, we ran over a similar scenario where solar panels could heat be used to heat the engine compartment, but it would take too many amps. At 20F, I'm not sure if a solar tank could help.

We even considered having a portable generator that could be attached to a cell-phone for "remote start" to heat-up the car. Weight, fuel, and cost-benefit considerations negated that as well.

The solution has to be the sun. It's out there all day and can generate some form of heat, right?

red91sit · 10-10-2006, 10:24 PM

Quote:

Originally Posted by rh77

A while back, we ran over a similar scenario where solar panels could heat be used to heat the engine compartment, but it would take too many amps. At 20F, I'm not sure if a solar tank could help.

We even considered having a portable generator that could be attached to a cell-phone for "remote start" to heat-up the car. Weight, fuel, and cost-benefit considerations negated that as well.

The solution has to be the sun. It's out there all day and can generate some form of heat, right?

Wouldn't it be far simpler to partially seal off the engine compartment? Radiator block helps a bit, but blocking up the bottom would do wonders i would imagine. The hood is usually sealed on cars, so why not work on blocking up the bottom as well?

I'm not to concerned about warming the vehicle up with my exhuast energy recapturing device :P

red91sit · 10-11-2006, 05:52 PM

kind of off topic, but what about solar panels to power an electric heater to warm the inside of the car? plug it in in the morning, go to work, park in the sun, drive home?

cfg83 · 10-11-2006, 07:14 PM

red91sit -

Quote:

Originally Posted by red91sit

kind of off topic, but what about solar panels to power an electric heater to warm the inside of the car? plug it in in the morning, go to work, park in the sun, drive home?

Even more off topic ... I have an old flexible Uni-Solar panel (USF-11 I think, 10 Watts, 16"*21" sqin) and a small "car battery" charger solar panel (6"*12" sqin). I am going to ask my Dad to make interface circuitry that mimics the car battery charger so that the Uni-Solar panel will be able to act like a big battery charger. He would know how to do this. It would be perfect in the rear back window or attached to the car roof during the day. That might give me a "re-charge option" if I were to try something that would risk my battery charge.

CarloSW2

rh77 · 10-11-2006, 07:29 PM

I used the cardboard rad block last Winter also -- it worked well. The problem with the 'Teg is that it really needs warmth to kick-in the TC. I was having problems (actually, it was around 50F here today and it took forever for it to kick-in).

My car's underside tray directs air up and into the rad area to cool it, so while the block helped, an additional grille block and partial tray may suit a dual purpose.

RH77

Bill in Houston · 05-03-2007, 05:59 PM

Interesting stuff. I hope it works well for you. You could route the windshield squirter onto the sponge and fill the tank with plain water. But then, you wouldn't have it for the windshield... Hmm...