This timing advance scam on ebay
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From: League City, Texas
This timing advance scam on ebay I know people are being scamed by this. My question is what exactly is it and why and how can these guys claim 20rwhp. I know it is just a resister that is about 30 cents but where does it go and what is it really good for? BTW is there a difference for the trucks?
Re: This timing advance scam on ebay The resistor would go in place of the Intake Air Temperature (IAT) sensor. What they are doing is putting a resistor in there that tells the PCM that the incoming air is cold. For example, maybe it tells them that the air is 32 degrees.
At hot temperatures (freeway, Houston, July - 120+ degree IAT's), the PCM *may* pull timing to prevent knock, so all these guys are doing is fooling the computer so that it doesn't pull so much timing.
Now, I say *may*, because on a mass air system, IAT isn't as important. I recall someone on the LT1_Edit mailing list - many moons ago - set up a benchtop tester for his PCM. Varying IAT made NO difference in spark advance when running in Mass Air (MAF) mode. Now, when running in Speed Density (SD), where the MAF sensor is taken out of the equation, the computer does rely on the IAT and the MAP sensor to calculate fueling. So, I can see in SD mode how this might help on a hot day, but on mass air cars, honestly, I'm not sure it'd do diddly squat.
Me, I simply relocated the IAT on my LT1 car so that it feeds out of the fenderwell, and doesn't get as heat soaked at the TB elbow. But on my LS1 car, there aren't as many options for placement, so I left it in the stock location.
I personally wouldn't mess with it, even though it's a 'cheap' mod. You get what you pay for in this case. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
-Andrew
At hot temperatures (freeway, Houston, July - 120+ degree IAT's), the PCM *may* pull timing to prevent knock, so all these guys are doing is fooling the computer so that it doesn't pull so much timing.
Now, I say *may*, because on a mass air system, IAT isn't as important. I recall someone on the LT1_Edit mailing list - many moons ago - set up a benchtop tester for his PCM. Varying IAT made NO difference in spark advance when running in Mass Air (MAF) mode. Now, when running in Speed Density (SD), where the MAF sensor is taken out of the equation, the computer does rely on the IAT and the MAP sensor to calculate fueling. So, I can see in SD mode how this might help on a hot day, but on mass air cars, honestly, I'm not sure it'd do diddly squat.
Me, I simply relocated the IAT on my LT1 car so that it feeds out of the fenderwell, and doesn't get as heat soaked at the TB elbow. But on my LS1 car, there aren't as many options for placement, so I left it in the stock location.
I personally wouldn't mess with it, even though it's a 'cheap' mod. You get what you pay for in this case. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
-Andrew
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Joined: Mar 2002
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From: Amarillo, Tx
Re: This timing advance scam on ebay It tricks the computer into thinking it is 55 degrees outside. So if it is not at least 75 then it wouldn't even be worth doing. I feel it helps at the track on hot days. Our track is pretty inconsistent but my best runs are with using it. I do what raughhammer had on his website which is to put it in and do a run and then remove it as quick as possible. The computer will overide the signal in a real short time.
