warm air intake is in

[brucepick]

I already have a kinda-warm intake. OEM airbox has a thermostatic damper that allows manifold-reheated air or outside cold air or a mix. And I installed an interior/exterior thermometer that tells me the net intake air temp.

I'm considering modding the damper so it never closes off the hot air. Would still close off the cold air in cold winter conditions. In summer it would likely run as high as 125 deg. to the intake. I'm just not sure whether that could heat-damage the amm (supposedly they're susceptible to this) or cause other problems. AMM + approx $200-300 so I don't want to mess it up. Even from a wrecker, its about $50.

[dieselbenz]

I wouldn't try it on the volvo with the hot wire amm. Those things are easily damadged by hot air and expensive to replace.

I'm not entirely convinced by this whole hot air theory. If it works the you should see your fuel economy drop with an efficient cold air intake. I think this has more to do with inefficient design in the factory intake than benefits from hot air

[GasSavers_BEEF]

My warm air intake uses the factory tube, box, and filter. I just put a tube in the box so that it gets it's air supply from the header/exhaust manifold. other than the source of the air, it is the same factory intake. I am currently seeing about 3mpg gain because of it. I haven't changed my driving style since putting it on. I purposefully waited two tanks before doing the WAI so that I could see the difference for myself.

theory, I don't know but numbers I do. at the end of this tank I will post in my gas log and hopefully my average on the scangauge is right.

part of the benefits from the CAI (cold air intake) are from the less restricted path and you will see that with either the CAI or the WAI if you use an aftermarket setup. mine is the factory setup with just air temp change. so you really see the difference of just the air temp. I did it this way because I am cheap, no other reason. even the e-bay special intake for my car was going to run me $35 or more. I spent $5 on the tube and a little more on flashing. that is it.

wether you buy into this or not is up to you. I am seeing about 10% increase in fuel economy and I drive 22miles one way to work. I am loving this. I am not quite ready to go crazy with my car and try to get more but I used to get 400 miles per tank flat. my goal now is 500 on a tank which equates to 2 free round trip tickets to work.

*edit* BTW pics are in my garage

[GasSavers_BEEF]

brucepick,

if you don't feel comfortable with it then don't do it. there are a lot of techniques on here that I have seen that I don't feel comfortable doing. I can't say wether it will damage your car or not by doing it. I wouldn't think it would unless the temps got way too hot. mine so far haven't gotten much over the 150 mark and I know that is hot. usually stays around 130s or so most of the time.

I simply started this thread because several people told me it was cheap, easy, and I could save some gas. I was sharing what I found.

It is up to you wether you do it or not. I am just sharing my results

[dieselbenz]

Originally Posted by BEEF

wether you buy into this or not is up to you. I am seeing about 10% increase in fuel economy and I drive 22miles one way to work. I am loving this. I am not quite ready to go crazy with my car and try to get more but I used to get 400 miles per tank flat. my goal now is 500 on a tank which equates to 2 free round trip tickets to work.

*edit* BTW pics are in my garage

I suspect your engine is simply reaching operating temperature faster because of the hot air going into the intake. A lot of manufacturers use this trick in order to reduce start up emissions.

[theholycow]

Originally Posted by tjts1

If it works the you should see your fuel economy drop with an efficient cold air intake. I think this has more to do with inefficient design in the factory intake than benefits from hot air

FWIW, a user on another forum reported significant FE gains from a cold air intake, and he did it for performance, not looking for any FE increase...

[GasSavers_BEEF]

take it or leave it...whatever

do what you want.

it worked for me

[tasdrouille]

It's simple really.

The gains from a CAI do NOT come from the temperature of the intake air itself, but from the usual lesser pre-throttle pressure drop with it versus a stock intake. Heck, with a properly designed CAI you can even get slight positive pressure at decent speeds. I could make a CAI looking like a maze, the air charge would be as cold as any CAI, but it would give poor FE and performance.

The gains from a WAI come from the higher efficiency of an engine when burning a warm mixture. There is plenty of actual research papers on this, it's a fact.

Now whether or not your ECU retards timing as part of its emissions control strategy is variable, but take any two identical intakes on a car that will not retard timing with air charge temperature, feed one cold air and the other warm air, from an FE standpoint, the warm air intake will win.

[dieselbenz]

According to bmw, the stock intake at operating temperature should is between 122-158f.
http://farm4.static.flickr.com/3104/...8bf16fe5_o.jpg
My own testing confirmed it. Since the engine doensn't have a knock sensor you are only supposed to use minumum 91 octane. I built my own forward facing intake to bring teperature down to ambient and use 87 octane.
http://farm3.static.flickr.com/2322/...e157d646_o.jpg
http://farm3.static.flickr.com/2018/...b9991bba_o.jpg
The difference in throttle response and peak power is surprising to say the least, especially at freeway speeds where air is being force fed in. I don't know yet how it will affect fuel economy but there is some evidence to suggest that it helps.
http://www.karlsnet.com/mopar/ramair.shtml
I also put together a wiring harness to intercept the IAT signal with a varibla pot and make the ECU think its breathing hot or cold air.
http://www.gassavers.org/showpost.ph...6&postcount=37
The first time I tried it, the CEL came on and it idled extremely poorly. I might have mistakenly picked the wrong range for the POT. I went by the repair manual sensor specs instead of testing the MAF itself. We'll see.

[GasSavers_BEEF]

well the results of my first tank are in since the WAI install.

I went over 500 miles with an average of 36.5+ mpg for the tank.

if you want more detailed info, see my gas log.

I think it is definitely worth a shot to try. I would research your particular vehicle as others have seen mixed results. I think that if you happen to have a cavalier, then I would definitely do it.

but that is just my opinion.