Modification: Warm Air Intake

[SVOboy]

If I can figure out how to do it, I'm going to get some dryer vent tubing and try to draw some warm air from around my exhaust manifold. My thought on doing this is this: I know the ECU is leaning out the mix because of the resistors, but I'm thinking that the warm air will help the fuel that IS being injected to burn more efficiently.

The closer the truth is to the lie, the better off you are.

[rh77]

I was concerned that tricking the ECU into thinking that the air was hot would lean-out the mixture too much, damaging critical components (This car is my daily driver, and it has to last me a few more years).

RH77

[diamondlarry]

The closer the truth is to the lie, the better off you are.[/quote]

I'm not sure I follow you on this comment.

[Matt Timion]

Originally Posted by diamondlarry

I'm not sure I follow you on this comment.

For what it's worth, neither do I

[SVOboy]

I'm not sure I follow you on this comment.

Well, the danger with leaning it out by telling it air isn't that there is means that the combustion will act a little funky, which was my problem, burnt to oddly that my car smelled like melting tin plates almost immediately from the resistor mod. However, this is because I was telling it it was 240 degress when it was 60, the huge difference created the problem, whereas a 240 degree to actual 150 degree difference would be more accurate, therefore less problem.

[diamondlarry]

I've been thinking about your funny smell for awhile trying to figure out what it may be. Is it possible that 110 ohms is to small an amount for your particular car and the smell was things getting to hot? Just a thought.
Larry

[SVOboy]

Yeah, my thoughts exactly, which is why my next mod will be with actual hot air, and then hopefully I'll be able to crack into my ecu and mess with things a bit there. I can decrease fuel injection by 10% a lot of places, and it'll be 10% for sure no outside affects or any of that stuff, it'll be an absolute 10%, but I can also fool around by have the IAT return different values than it's reading and shutting of the ac at certain load levels and tons of stuff.

[SVOboy]

<a href=http://insightcentral.net/forum/viewtopic.php?t=2546&sid=5a6bd2d1a61e1487ba75ef939 73921f4 target=_blank>Another WAI/HAI set-up</a>
<a href=http://www.cardomain.com/ride/581466/2 target=_blank>Another!</a>
<a href=http://www.cardomain.com/ride/581466/3 target=_blank>Another!'s update</a>

[MetroMPG]

Originally Posted by SVOboy

the danger with leaning it out by telling it air isn't that there is means that the combustion will act a little funky

did some reading about WAI's today... and this is a good point that isn't mentioned often enough when just tweaking the sensor.

aside from just "fooling" the AIT sensor into thinking the air is warmer than it really is (with the resultant ECU response on A/F mixture), there are real efficiency benefits to warming the air itself.

another one that's not mentioned much, is that warm air is easier to pump (because it's less dense), so the engine experiences less pumping losses - less energy is spent drawing warm air into the combustion chamber than cold air.

so the benefits of WAI that i've been able to figure so far:

• OBD ECUs will run the system leaner than at low IA temps
• possibly contributes to better cold fuel vaporization
• reduced pumping losses from lower air density
• pumping losses further reduced by wider throttle opening for a given RPM to compensate for reduced power. (see this page for explanation)
• contributes to quicker engine warm-up

so on my car today i moved from a "mild" air intake (snorkel to the stock CAI simply unplugged) to a WAI approach - additional snorkel length added to draw air from around the exhaust manifold.

the change raised my intake air temp from a max of 60F at 30f ambient to a max of 75F in a brief (20 min) city/hwy run. i may further shield the collection end of the WAI to improve this.

i'll run a thorough controlled-as-possible scangauge test to see if there's a measurable effect on mpg on my car... sometime... before spring...

[SVOboy]

Obd1 honda ecus will correct as much as 6% leaner or 24% richer from warm to cold intake air temperatures, just food for thought. I think the benefits dip off after 120 F, but I could check to be sure if you want me to. I'm pretty sure it'd be equivalent on most cars.