ATAP for Headers
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TECH Fanatic
Joined: Nov 2001
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From: PURDUE
ATAP for Headers Ok, I borrowed AutoTAP from a friend of mine (i've never used AutoTAP BTW). I'm going to AutoTAP my car before AND after I install my Hooker LTs tomorrow. What all should I have AutoTAP look for? Obviously my main concern is my air/fuel ratio. Opinions?
11 Second Club
Joined: Nov 2001
Posts: 300
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From: Central Florida
Re: ATAP for Headers When you get on a dyno, make sure they can pull A/F ratio. Your main concern with ATAP will not be your A/F ratio.
With ATAP, you'll need to do what everyone else does...
First, be sure to log your LTrims at normal driving conditions. This will indicate how lean/rich your car is running. Optimal LTrim values are generally between -2.0 to 2.0, positive being a richened condition and negative being leaner.
Next, log a few "spirited" runs. Make sure you go to WOT, so try to head for the redline a few times. The more data you log, the better an average you will obviously attain, giving you a statistically more accurate picture of your car's behavior at WOT.
Using a spreadsheet, you'll want to fish out your O2 sensor readings at WOT. WOT is defined as FTC = 22 and TPS > 80. I used Microsoft Excel to create a Visual Basic function to add these values up and average them. You could also use the conditional sum wizard to do the same thing. This average will tell you where you stand with respect to O2 sensor readings at WOT, which should be in the range of 0.875 to 0.910.
If your car hits those ranges, you'll likely be in great shape. Likely, if you've modded your car and have done nothing to correct the stock program, you will not attain these ranges of values. I have yet to see a modded, stock-programmed car pull this off without the use of a MAFT.
Search this forum for what parameters to log. I could tell you, but you'll learn more from researching the threads on this board than me telling you outright, since there's a lot of good, detailed information here. There's also a detailed write-up on one of the Corvette Forums regarding this information, but I can't remember where it is. Try to read it all in detail. It will teach you a great deal about how your car's computer handles engine management under different conditions.
Best 'o luck to you.
With ATAP, you'll need to do what everyone else does...
First, be sure to log your LTrims at normal driving conditions. This will indicate how lean/rich your car is running. Optimal LTrim values are generally between -2.0 to 2.0, positive being a richened condition and negative being leaner.
Next, log a few "spirited" runs. Make sure you go to WOT, so try to head for the redline a few times. The more data you log, the better an average you will obviously attain, giving you a statistically more accurate picture of your car's behavior at WOT.
Using a spreadsheet, you'll want to fish out your O2 sensor readings at WOT. WOT is defined as FTC = 22 and TPS > 80. I used Microsoft Excel to create a Visual Basic function to add these values up and average them. You could also use the conditional sum wizard to do the same thing. This average will tell you where you stand with respect to O2 sensor readings at WOT, which should be in the range of 0.875 to 0.910.
If your car hits those ranges, you'll likely be in great shape. Likely, if you've modded your car and have done nothing to correct the stock program, you will not attain these ranges of values. I have yet to see a modded, stock-programmed car pull this off without the use of a MAFT.
Search this forum for what parameters to log. I could tell you, but you'll learn more from researching the threads on this board than me telling you outright, since there's a lot of good, detailed information here. There's also a detailed write-up on one of the Corvette Forums regarding this information, but I can't remember where it is. Try to read it all in detail. It will teach you a great deal about how your car's computer handles engine management under different conditions.
Best 'o luck to you.
