Let's talk WAI

[theholycow]

Originally Posted by drifttec101

The whole point to this thread was to show that all mods we do essentially detune your car, and a shortcut to doing that would be to press the gas peddal less. If you put your car on a dyno with the hot air intake, then with a normal air intake you'll see power loss with the HAI. I don't think anyone is going to dispute that.

Nobody will dispute that the maximum power is reduced. However, nobody here is using the maximum power, so adjusting it doesn't affect fuel economy. The reduction in power is not the cause of the fuel economy increase; it is a side effect.

Saying that reducing the maximum power available causes the fuel economy increase is like saying that losing your hair battles cancer. Chemotherapy is what battles the cancer; the hair loss is a side effect. Shaving your hair won't accomplish the same thing.

With cars the issue isn't as clear-cut, because people who drive wastefully will find that easing off the go-pedal produces an increase in fuel economy. It's not because of the closed throttle; it's because they're driving slower.

As my gaslog thoroughly proves for my VW, an open throttle is better for fuel economy than a closed one. Stepping on the pedal less forces me to let the RPM run up higher before shifting and wastes gas. Whether I floor it or feather it, I drive the same speed.

With automatics the issue gets muddier, because the go-pedal operates the throttle AND the transmission. Now to get your RPM down you have to back off the pedal. Then you add in torque converters that lock sometimes and slip other times and it gets impossible to create a general rule. My GMC needs to be accelerated somewhat harder than would be most efficient with a manual transmission, because if I'm too gentle it wastes a lot of energy sloshing the transmission fluid.

So, yes, an automatic with a wasteful driver is likely to see a great improvement by closing the throttle, in spite of the additional throttling losses. The lower speed and better transmission behavior save a lot more fuel than the closed throttle wastes.

Don't waste time on some miracle fuel saver, just drive more conservatively. You wouldn't waste time and money on some cure all miracle pill would you? Well actually Americans do that all the time... it's a problem.

That is one of the biggest beliefs shared on this site. We don't believe that you can spend your way to efficiency, and most of what the successful hypermilers here do is done with driving techniques. A cliche here is that the best nut to adjust is the one behind the steering wheel.

The nice thing about the WAI is that you don't need to spend money on it. It can be done mostly with scrap materials and DIY labor. We're not talking about some device marketed for fuel economy by someone with a profit motive.

If the OEM could improve efficiency by 50% or 100% by some simple modification they would do it.

That is the first thing I think of when I consider anyone's idea of modifying a car, whether they're interested in fuel economy, power, or anything else. I often post that. If the manufacturer could do it better, why didn't they?

They are, however, required to make a lot more compromises than an individual can. Here's a couple I can think of off the top of my head that directly affect the WAI idea:
- All climate and load conditions: The same model gets sold for use in Death Valley and and Alaska. The same model is sold to people who want to tow a trailer at 80mph as is sold to the hypermiler who wants to plod along at 50mph.
- Marketing: They'd definitely sell less cars with a WAI, which runs counter to everything that most car people believe in. Besides that, fuel economy is just not that important to consumers, except during short periods of abnormally high fuel prices before the consumers get used to it.
- Thoroughly proven, mature technology: They tend not to want to put in technology that's only been used extensively in experimental and DIY applications. They don't want to have to spend the money on the kind of testing they need to do before they can mass produce it for all markets.

There's more, I'm sure. Then, on the other hand, there's the big issue of fuel economy; but any manufacturer who's not catching any CAFE fines isn't worried about it. Once they manage to meet CAFE requirements, they quit improving fuel economy and go back to making more power.

[drifttec101]

Dodge Neons have no performance or comfort, they are economy cars. 2.0 liter, SOHC, no PS or even power windows on mine... that yields more efficiency than it does performance.

This is what I'll do... There's not really enough room to cut a hole in the of the stock air intake box, but a 2.5 inch shop vac hose can plug right into the underhood box. With that hose I can either run it into the fender well, or run it somewhere underhood. I'll get some sort of door sealer to seal the stock air box as well just so I'm not getting hot air to the filter when I'm testing the cold air or vise versa.

I'll a series of short runs on each setup (same distance on the same day). My run will be from home to Home Depot which is a mix of city and highway driving, more highway however. Then after doing that several different days, I'll run a week long normal driving test on each setup. That will be almost completely city driving and gas mileage will calculated, not read from the scangauge. I will record the air intake temperature for all of the above.

If I get 120% over EPA I'll crap my pants. Look for me in the experiments section.

[spotaneagle]

Originally Posted by SentraSE-R

I don't doubt a WAI can help in some applications, up to 5% or so. But I've yet to see anyone produce ABA testing results to prove it. Anecdotal testimony from the Johns of the world, claiming 50% improvement based on a non-repeatable single tank, have to be challenged, simply because they're not credible.

I'm averaging ~170% of '08 EPA combined estimates on each of my two cars over 24,000 miles, so I know what it takes to achieve good mileage. John hasn't managed to bring his average up to 120% of EPA. I should be teaching him, not vice versa.

no
5 % is wrong

my average average fill up of 29 28 lowest 33 highest up to 36mpg 39 mpg higest usually-33 lowest

thats a 24% increase(15-20% at least to be safe.. theres no definitive amount but the thing is WAI has the hybrid effect where it works better in the city, mostly because there's less air hitting your car(cooling it down), I also have a feeling this would work better with automatics because they achieve higher speeds at lower rpms, for one, two, because you can set you target temp higher because there will be less confusion about clutch release height ect.. Which you can master the new method quickly if your good on a stick.............

it will increase your city mpg to 34 up from maybe 20-23 because it will be running ultra efficient(not lean) at that point

my 42 mpg is straight 70mph highway driving for 200 miles with 2-3 stops for breaks with my warmer air intake(not actually over my headers but next to engine) I've had a setup on another saturn automatic where I reduced the intake hose radias a little and put it much closer to the headers, right in front of the headers, and got 45 mpg at 65mph, so thats more like 30-33%, not running lean, yes the fuel air ratio was the same

[FrugalFloyd]

Uh, spotaneagle. Would you or John kindly explain to me how an air density decrease of ~5% translates into a 24% or 50% fuel economy improvement? Dry air at 20?C has a density of 1.204 kg-m to the -3 power. Dry air at 35?C has a density of 1.146 kg-m to the -3. That's a 4-5% difference, not 24% or 50%. There's a bigger difference between -5?C and +35?C, but it's still only 15%, and John (project84) claimed his 50% improvement in July.

So give me a scientific explanation of how this miraculous improvement is supposed to work.

[Project84]

Originally Posted by spotaneagle

free thinkers destroy the status quo, and people stuck in their ways can't possibly deal with it!

I like his signature... sums it up I think.

[spotaneagle]

well, one your injectors(and the amount of fuel they use/you save) don't respond directly to air density, so lets put that behind us... more a sum of air density(map) exhaust fumes, and whatever else, regulated by your cars computer.

block tempurature/ cooling system temp, have a direct correllation to mpg, because when it is colder it uses more gas to stay warm.. this is one of the benefits of grille blocking

im sure that recycling heat and keeping your cooling system a little warmer might account for 8 even 10% too... also this might work better on lighter cars, I have a 2368lb saturn(40 lb lighter than automatic) like the effects multiply one another, but some people here dont think so, i disagree 800 lbs makes a difference, why do saturns beat likewise integras (800lbs heavier) on every front including mpg/ quickness (stock) when it comes to efficiency, but have basically the same size engines 1.8-2.0's?

[spotaneagle]

i dont think WAI will work well on sports cars either especially super charged or turbo cars condsidering the velocity of the air moving into and out of the engine.. I would think the higher horsepower your car has the less wai would work also, because the velocity at which the engine pulls in air is greater(finding more colder air from the outside, I would almost assume that anything near or over 190 hp you might find this, I could be wrong though..

Though, you can get tuners that lower your horsepower and give you better mileage, so I've heard

[drifttec101]

Originally Posted by spotaneagle

Though, you can get tuners that lower your horsepower and give you better mileage, so I've heard

That's the definition of detuning.... that's what I'm talking about!

I agree with SentraSE-R... The numbers people claim just don't add up. It reminds me of those resistors that are sold on ebay that claim 50 extra horsepower and 30 extra mpg. But I'm not saying that anyone is lying about their numbers. There may be more going on behind the scenes. What I want to get at is why does a WAI work ? What is it doing to fuel maps? Is there another way of doing it? etc...

[Jay2TheRescue]

Originally Posted by drifttec101

Dodge Neons have no performance or comfort, they are economy cars. 2.0 liter, SOHC, no PS or even power windows on mine... that yields more efficiency than it does performance.

They're really not economy cars. They were designed to be small & cheap. Their economy is just a byproduct of being small & cheap. If the primary goal in designing the Neon was economy then they would get better mileage.

[theholycow]

Originally Posted by drifttec101

That's the definition of detuning.... that's what I'm talking about!

That type of detuning isn't just turning down the maximum horsepower, though. Again, the reduction in power is a byproduct. You turn off this enrichment condition, adjust the ignition timing that way, tweak some other thing some other way, etc, for the purpose of increasing fuel economy; and in doing so, you give up power.