DTN

Ok, so my computer thinks the input air is about 50F higher then it actually is. This will be my first tuning project with my ELM-scan I bought from Jay-M's sale. I plan on putting a potentiometer inline with my temperature sensor and adding resistance until the temperature is within range. Maybe that e-bay thing isn't too far off.. We'll see. I've got my IAT out and i've been playing with it. It seems that the sensor works on a negative co-efficient, which means as it gets hotter, the resistance goes down. I'll keep you all posted. Maybe this could be a good mod for any tib, i dunno. I do know it's about 50F out, not 108F.

on my sensor 77.5F = 1.74 Kohms

54.0 = 3.24Kohms.


28.2 = 6.50Kohms

Edit:
LOL... It's looking like in order to get the temp right, i'll have to add a e-bay mod chip lmao.gif lmao.gif lmao.gif lmao.gif lmao.gif lmao.gif

In all seriousness, maybe there's something to that, can someone get me a ohm reading from their sensor and a current temp?

Tiburonsrule

Im sure you know that tibs run by nature. Tricking your IAT into thinking colder air is entering will make your computer run even more fuel into the engine. Resulting in an extremely rich fuel mixture.(not good for power)
so I dont think its such a good idea. Theres more to tuning than just throwing in a resistor.

Just out of curiosity are you testing intake temps when the engine is cold or after it is warmed up?

DTN

I've heard that, but I now don't believe it.





I had just got back from a fast and furious highway run monitoring different things to see how they react to different speeds and all. I pulled out my IAT because it was reading so high, i separated the legs a bit further because that usually lets you adjust temperature on a thermister. I ended up snapping a solder off and only dropping the temperature by 20F. So i brougt it up to my work area and resoldered and tested it. The ohm readings are completly out of the car. They are readings of actual temperature vs. ohms provided by the 2 wires comming out of the IAT. It's a thermister, it's only function in life is to lower ohms as it gets hotter out.

REDZMAN

Doesn't matter if you Believe it or not, it's fact.


Most Asian cars run rich. The reason being that there are many less problems on a car if it runs a bit rich than if it runs lean. To ensure that the car will run for almost EVER, they run them rich. Hyundai's run "Pig Rich", or much more rich than they need to. Tis a fact. This is why a SAFC 2 will show you some nice gains, and really improve your MPG and such, but since the ECU learns, it's not worth it. Why do you think your exhaust, even right after it's cleaned, will be black as hell soon?

DTN

^^ I have a real problem even trying to believe that my car is running rich with it reading 50 degrees above the current temperature. That's alot of density compensation.

REDZMAN

Ehh, were you expecting the air intake temps to be the same as the outdoor temperature?

Not gonna happen.

DTN

^^ with the IAT unplugged and shielded from engine temps at night in free air, yes. There's something different, maybe it's just my sensor or something, but It's not reading the correct temperature, that's for sure. 50 degrees is a big difference.

There was only a diference of 4F between the intake piping from my CAI and air temp.

nate704

i'm just wondering what's the point of this mod?

All i can see is that you are gonna run it richer than ever, lose poser, and a lot of carbon's gonna build up in your head, manifold, plugs, and cylinder area. cool.gif

DTN

^^ The first o2 sensor and short term fuel trim are what really controls AF ratio.

01tibby

mine reads about the same. 90 degrees on a 45 degree day. course i only ever look at it after i've been driving for a while, so it might be mostly engine bay radiant heat.