Re: What exactly does the IAT sensor affect?

From: Ken Allgood (kenallgood@cox.net)
Date: Mon Mar 10 2003 - 17:51:48 EST


I'm not sure if the A/F ratio is directly impacted or not, but I believe it
is...... If I remember correctly, this is what happens. The IAT sensor
tells the engine that there is colder air coming into the engine, and I
believe this makes 2 things happen:

1) Colder air is denser, so you have more air in the combustion chamber, so
you need more Fuel in the combustion chamber to get proper combustion.
(This is what all the hype about cold-air intakes is about)

2) Avances the timing a few degrees due to the colder air (I'm not sure why
exactly it does this, probably related to item #1, but I'm not sure, not an
engine expert here).

There are some pros and cons here. 1 is if you get more or colder air and
fuel into your combustion per firing cycle, you get more HP. The downside
is by getting colder air in there, the timing is advanced, and you could get
detonation (spark knock). This leads into other modification such as colder
spark plugs, etc to prevent the detonation because it's pretty bad if you
let it go on.

Hope that helps some (if I'm right.. hehe).... To answer you're question
more directly, I believe it effects both A/F ratio as well as advances the
timing.......

----- Original Message -----
From: "Kyle Vanditmars" <kylevan@telus.net>
To: <dakota-truck-moderator@bent.twistedbits.net>
Sent: Monday, March 10, 2003 4:42 PM
Subject: DML: What exactly does the IAT sensor affect?

>
> Ok, I've been reading around, and I'm confused as to what exactly the IAT
> sensor affects on the engine. KRCPerformance.com says it advances timing
> when it detects colder air, but I was under the impression if affected the
> A/F ratio. Could someone with some actual knowledge let me in on the
> secret?
>
>



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