Recovering lost heat energy in engine coolant...

[t vago]

It's one consequence of artificially lowering your maximum power output via a HAI/WAI.

Unfortunately, like my Dakota with its 45RFE or my Magnum with its 42RLE, many newer vehicles can't really use a manual valve body, because those vehicles have completely computer controlled automatic transmissions. I can compensate somewhat on the Dakota, because I have rigged up a simple circuit that tells the transmission computer that the throttle is less open than it really is. However, as the Magnum has an integrated transmission and engine computer module, that's not an option for the Magnum.

[mechman600]

Originally Posted by t vago

I can compensate somewhat on the Dakota, because I have rigged up a simple circuit that tells the transmission computer that the throttle is less open than it really is. However, as the Magnum has an integrated transmission and engine computer module, that's not an option for the Magnum.

What determines the kickdown on the Magnum - TPS alone or a calculated load percentage? If it only the TPS, there might be a simple workaround. Simply create a manifold vacuum leak to the air box. That way the throttle angle will always be less at a given load than it normally would be and the transmission won't kick down as soon.

[Christ]

You'd have to valve that, as well.. to control the air bleed, at least at first, until you learn how much compensation the PCM will add... at some point, it's going to say 'No way, Charlie!' and stop adding fuel, kick the CEL on and in some cases, drop into 'limp home' mode.

[California98Civic]

What a great thread! Read through the whole thing, with thanks. Some confirmations and a question:

Originally Posted by t vago

The intake heater, as installed, appears to give a reliable 45 F delta T between the outside air temperature...

My WAI has tended to give me 30 degrees F over ambient. I have loosely observed that many times driving around listening to radio weather reports, public temp displays, and observing my IAT sensor readout on my ultragauge.

Originally Posted by t vago

Part Load Pumping Losses in an SI Engine ... Changes of Low Load Engine Parameters by Temperature of Mixture

I think that this paper is showing that the resulting gain in fuel economy from installing a HAI is a combination of the two factors.

That is useful to know. I have always just taken the line I learned from Daox about pumping losses as being the whole explanation.

A question: I did a WAI test myself two years ago on my MAP equipped Civic. The results confirm yours, though my IAT and FE gains were not as great. But had to use steady throttle position in the place of cruise control since I do not have CC. I saw a modest increase in what I thought was a fairly rigorous DIY test, but it has been suggested to me that using throttle position invalidates the results. [Here are the results. Any thoughts on the validity of my test?

Thanks.

[t vago]

Originally Posted by mechman600

Simply create a manifold vacuum leak to the air box. That way the throttle angle will always be less at a given load than it normally would be and the transmission won't kick down as soon.

As Christ said, it'd have to be trial and error with a valve. I'd likely see P0121 and P0221 codes if I caused too large of a vacuum leak. The engine computer compares throttle sensor positions against manifold air pressure sensor readings, and the throttle itself is one of them drive-by-wire types (not like in the Dakota, where I could spoof the throttle position as needed).

[t vago]

Originally Posted by California98Civic

What a great thread! Read through the whole thing, with thanks.

Thanks! I've been wanting to get some sort of gathering of WAI information together in one place.

Originally Posted by California98Civic

My WAI has tended to give me 30 degrees F over ambient. I have loosely observed that many times driving around listening to radio weather reports, public temp displays, and observing my IAT sensor readout on my ultragauge.

I do the same thing. I monitor engine coolant temperature and intake air temperature fairly regularly. I've noticed that the temperature differential is lower as outside air temperature rises. Right now, I'm looking at about a 40 F difference. In the wintertime, it was more like 60 F.

Originally Posted by California98Civic

That is useful to know. I have always just taken the line I learned from Daox about pumping losses as being the whole explanation.

I thought the same thing, at first. However, when I first started testing a WAI in the Dakota, I noticed that the manifold pressure never really changed that much, nor did throttle position, yet I was still able to get as much as 6% improvement in fuel economy.

It may have something to do with warm air causing better atomization of fuel, perhaps. Or, as I have thought about over all this time, it could also be that since warmer air is less dense than colder air, for a given absolute pressure, it takes less energy to draw a vacuum with a WAI, than it would with a normal (or CAI). Or maybe it's a combination of both factors.

Originally Posted by California98Civic

A question: I did a WAI test myself two years ago on my MAP equipped Civic. The results confirm yours, though my IAT and FE gains were not as great. But had to use steady throttle position in the place of cruise control since I do not have CC. I saw a modest increase in what I thought was a fairly rigorous DIY test, but it has been suggested to me that using throttle position invalidates the results. [Here are the results. Any thoughts on the validity of my test?

Your results look good to me. In fact, that post of yours was one of several on this board, that led me on my own WAI path. So, my hat's off to you, sir.

Not sure how throttle position is supposed to invalidate your results, though. It looked like you tried to minimize the variability of other major factors involved (speed, distance traveled). *shrugs* Others here have also duplicated your results.

[pgfpro]

Awesome thread t vago!!!

I'm going to start on my WAI this weekend using my turbo as the heat source and by-passing the front mount inter-cooler. I might try to block it first but as Summer is almost here I'm sure I will need the air flow to get to the radiator.

I'm lucky when it comes to my car 1991 AWD Talon OBDI with ECM Link V3 SD management (will log over 40 different parameters including my wide band O2) and a re-chip TCU that has two options. Manual shift full line pressure so I can be in over drive at any speed/rpm and a race mode with preset shift points at full line pressure.

Since I installed the chip TCU I improve a ton on in city fuel mileage. What happen though is after the TCU chip install the stock converter was slipping at 20mph to 35mph in OD so I switch to John Deer HyGard fluid and it helps a ton with the converter slippage. Plus I use my car for racing also and HyGard is the new fluid that many racers are now using to handle the extreme loads that the trans is seeing at a much higher HP then stock.

[gumby79]

Any progress or is this project one for the bad idea pile. I hope progress.

[Fingie]

Same here. I had a short ram filter on the War Wagon before, which raised intake temps to even 90F. according to the OBD-II reading.

Later the car developed knocking, I got scared that I've raised the intake temps too much (it was the new plugs, I was an asshat to not check)

So I switched to CAI. intake temps are 71 F at about 32F

I am converting the car to ethanol gas very soon.

So do you people think WAI would help with FE, as ethanol is "leaner stuff) than gasoline and thus needs to be injected more.

Although E85 has a higher knock resistance compared to gasoline.

[oil pan 4]

Alcohol takes a lot more latent heat to vaporize it.
A warm air intake seems like it would be a good idea for an alcohol engine that you want to have good fuel economy.