What does unplugged IAT do?
06-11-2003, 03:02 PM
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What does unplugged IAT do? on my ls1 conversion, i never got a chance to install an IAT yet becuase my airfilter is directly bolted to my MAF and i havent added piping to put in a IAT.
If my IAT is unplugged, what does it do?
Also, in LS1Edit, what table can i set all the IAT map timing to 125 degrees???? And this will result in temp not effecting timing.
If my IAT is unplugged, what does it do?
Also, in LS1Edit, what table can i set all the IAT map timing to 125 degrees???? And this will result in temp not effecting timing.
06-11-2003, 03:06 PM
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06-11-2003, 04:37 PM
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Re: What does unplugged IAT do? The IAT is a thermistor. Low intake air temps produce high resistance (aprox 101k @ -40C) while high intake temps cause low sensor resistance (aprox 80 ohms @ 130C). The IAT sensor signal voltage is used by the PCM to assist in calculating the fuel injector pulse width, idle speed, canister purge and timing.
Where the IAT plays its role is in the 'Air density system'! Air density is derived from IAT and MAP sensor inputs. The IAT sensor measures the air temp that is entering the engine. This signal works in conjunction with the MAP sensor to determine air density. As the intake manifold pressure increases, the air density in the intake manifold also increases and additional fuel is required. This info from the IAT and MAP is used by the PCM to control injector pulse width.
The 'Air density system' is used in conjunction with the MAF to determine fueling management and timing.
You can do the 'timing tricker' mod by replacing the IAT sensor with a 4.7k ohm resistor (or somewhere around there). I personally have experience knock with this mod but can be used in a pinch. Do a search on "timing tricker"
With no IAT, the R = infinite so Temp is greater than 130C. Therfore your fuel management is put into Failure and Effects Mode along with a retarded timing. Result - performance loss.
Where the IAT plays its role is in the 'Air density system'! Air density is derived from IAT and MAP sensor inputs. The IAT sensor measures the air temp that is entering the engine. This signal works in conjunction with the MAP sensor to determine air density. As the intake manifold pressure increases, the air density in the intake manifold also increases and additional fuel is required. This info from the IAT and MAP is used by the PCM to control injector pulse width.
The 'Air density system' is used in conjunction with the MAF to determine fueling management and timing.
You can do the 'timing tricker' mod by replacing the IAT sensor with a 4.7k ohm resistor (or somewhere around there). I personally have experience knock with this mod but can be used in a pinch. Do a search on "timing tricker"
With no IAT, the R = infinite so Temp is greater than 130C. Therfore your fuel management is put into Failure and Effects Mode along with a retarded timing. Result - performance loss.
06-11-2003, 06:24 PM
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Re: What does unplugged IAT do? Summarized: Ok, so basically im losing horsepower with an unplugged IAT??
Unplugged = 130C! thats like 200+ degrees. How much power do you think this will cost me on the dyno. Im back dynoing my car all day on my dynojet so im curious on hearing more about this.
With ls1edit should i just change the values to 125F?
Unplugged = 130C! thats like 200+ degrees. How much power do you think this will cost me on the dyno. Im back dynoing my car all day on my dynojet so im curious on hearing more about this.
With ls1edit should i just change the values to 125F?
06-11-2003, 07:53 PM
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Re: What does unplugged IAT do? All I know, is that I left my IAT unplugged by accident one time, and I got an SES light. That probably didn't help you, just sharing my experience.
06-12-2003, 09:37 AM
#6
On The Tree
Re: What does unplugged IAT do? No IAT and you should get a light.
C4VetteLS1 start here. I would recommend either placing your IAT SOMWHERE near the intake to get a reading on the ambient temperature. This will be close enough as the temp shouldn't vary much on a cold air intake. IF you don't have an IAT sensor, hit up your local RatShack and get yourself a resistor. Just bend the legs on the resistor to be able to plug it in to where the IAT goes. It will cost you more in gas to drive there than to buy the resistor. <a href="https://ls1tech.com/threads/showflat.php?Cat=&Board=UBB23&Number=33227 3&Forum=UBB23&Words="timing%20tricker"& ;Match=Entire%20Phrase&Searchpage=0&Limit= 25&Old=3months&Main=332266&Search=true #Post332273" target="_blank">START HERE</a> to get R vs T and choose your poison. Either of these are a better option than running without due to you will be in a Fail And Effects Mode without. And yes FEM = HP loss.
C4VetteLS1 start here. I would recommend either placing your IAT SOMWHERE near the intake to get a reading on the ambient temperature. This will be close enough as the temp shouldn't vary much on a cold air intake. IF you don't have an IAT sensor, hit up your local RatShack and get yourself a resistor. Just bend the legs on the resistor to be able to plug it in to where the IAT goes. It will cost you more in gas to drive there than to buy the resistor. <a href="https://ls1tech.com/threads/showflat.php?Cat=&Board=UBB23&Number=33227 3&Forum=UBB23&Words="timing%20tricker"& ;Match=Entire%20Phrase&Searchpage=0&Limit= 25&Old=3months&Main=332266&Search=true #Post332273" target="_blank">START HERE</a> to get R vs T and choose your poison. Either of these are a better option than running without due to you will be in a Fail And Effects Mode without. And yes FEM = HP loss.
