Running a WAI through the wringer

[FrugalFloyd]

First, photos. Then we'll discuss the testing.

My Scion's air filter box, IAT sensor (I presume), and intake piping.


This is where my air intake was, in front of the battery, behind the radiator. I
connected my WAI over the 3" diameter plastic pipe that looks like a little horn, and snaked it back over itself. I had to remove the battery to get the WAI tubing into this tight compartment spacing.

[FrugalFloyd]

This photo shows my engine's plastic cover, with the exhaust manifold in the rear of the engine bay (left of photo). I'm going to take my warm air from atop the exhaust manifold. The battery and air intake you saw in the previous photo would be to the upper right of this photo, and the front left of the engine bay.


This is my $13.54 WAI. It's a 3" diameter, 5' long flexible metal heater exhaust pipe.

[FrugalFloyd]

Here's the mockup of the WAI before I coupled it up. I'm just going to duct tape the 3" heater hose over the 3" OEM air horn.

[FrugalFloyd]

Now to discuss the testing. I will do ABA testing, using my Scangauge to run a measured roundtrip route with cruise control, and the WAI installed. That will be B testing.

For A testing, I'll re-route the intake from the exhaust manifold area to the front right corner of the engine bay, where it will take in relatively cold air from behind the radiator, but lower down and on the opposite side of the engine compartment than the OEM air horn. I'll run the route at the same cruise-controlled speed, in the same gear, for each ABA series. I'll probably run both slow (35 mph) and fast (55 mph) routes. I can't run them on the same road, but I'll run the slow route on a frontage road paralleling a freeway, and the fast route on the freeway. Since I'll have to turn around on each route, I'll cut the cruise control at the same place for each ABA series, and accelerate as similarly as possible on each test.

I'll measure IAT, current trip average fuel economy, and trip distance. I'll record speed, temperature, wind, and road conditions.

Now's your chance to give me input on what else you'd like to see in this test, before I actually go out and do the testing.

[kit352]

sounds good. will that tubing clear the hood or are you gonna have to mash it down?

[Philip1]

since you have a scangauge it probably wouldn't hurt anyones feelings to log the GPM rate with and without. I hate to say this but due to the Scion using a MAF system you might not see any change MIGHT not.I await the results with anticipation.

[Project84]

I realize you're using cruise control to keep a steady speed but in real life, I've seen mpg drop using cruise control. I don't think it's highly regarded among hypermilers... they all prefer the good ol' foot. Oh well.

I suggest a heat shield.

Check tire psi before each trip. Make sure its consistant. Highway driving will warm the tires and the psi may creep up on you a bit.

I suggest you do each trip with the engine warm and at a predetermined coolant temp, lets say 180*F starts your trip.

Remember to reset your ScanGauge each trip too!

I suggest you drive a minimum of 5 car lengths behind anyone in front of you at all times. No passing unless emergency.

Do not use A/C.

If your IAT's aren't more than 60*F above ambient, I suggest you mod it until it is 60-70*F above ambient at city speeds.

You've got to figure out if that is your IAT sensor and not just presume. There is no truth in a presumption.

I'm not sure I trust JUST the scangauge either. All of my gaslog entries are my actual miles driven divided by the actual fuel required to fill the tank as observed on the pump or on my reciept. You want ABA, why rely on an electronic device that is doing 10,000 calculations per minute? It would be nice if you could completely top off the gas tank w/ a funnel and a gas can and measure each time how much fuel (by weight or by ml or ounces) it took until it was visible in the fill neck.

How far will your test route be? It must be a substantial mileage if you wish to see any real gain/loss in this test. I suggest 20 miles or more for each trip... and even that is not really enough, but in the efforts to not waste fuel, it should do. I'd prefer to see the testing done over 40 mile (or more) test loops, same day, one test after another as quickly as possible so there are little/no variables in wind, temperature, traffic, etc.

I could probably think of 5 more, but for now, I'll stop.

[GasSavers_BEEF]

my dad has an '06 corolla and it has the same MAF sensor that yours has. I don't think that you have an IAT sensor. you can still derive Incoming Air Temperature but I don't think you have the sensor.

IAT sensors are typically 2 wire devices.

this is the replacement for the sensor you are picturing (MAF sensor courtesy of rockauto.com)

[theholycow]

It's impossible to eliminate all variables in grassroots testing; there will always be plenty that can't be accounted for. You'll do the best you can.

It's nearly impossible to measure fuel usage perfectly for this. Again, you'll do the best you can.

Originally Posted by Project84

I realize you're using cruise control to keep a steady speed but in real life, I've seen mpg drop using cruise control.

As long as the drop isn't different for WAI than it is for CAI, that shouldn't be an issue. He's using the same cruise control for A and B.

It would be nice if you could completely top off the gas tank w/ a funnel and a gas can and measure each time how much fuel (by weight or by ml or ounces) it took until it was visible in the fill neck.

That does not sound practical, but something like that could be more accurate.

[Project84]

I worry about cruise control with increased IAT. Why? Because there's no secret in the reduction of engine power/performance while a HAI is in place and up to temp... thus, using cruise will require more fuel to power the car at the same rate as not using the HAI. As I think CC is wastefull in itself (excess fuel/throttle used as viewed using a vacuum gauge hooked up to manifold vac while on interstate), how much more wastefull will the computer be (fuel control wise) to compensate for the IAT's 60-70*F above what its used to reading?

Yes, you have to add more foot pressure when not in cruise while running a HAI so you'd say it all evens out, but I'm just saying, hypermilers do it w/o cruise to achieve best results... I think cruise will skew the results a bit.

Honestly?

I'm trying to be a stickler. I have my reasons.