What is the proper air/fuel ratio?
Re: What is the proper air/fuel ratio? Your car has two target A/F ratios
14.8 for maximum efficiency and emmissions while just cruising around in part throttle conditions
12.3-12.8 for maximum power. This is your WOT a/f ratio
Headers, will affect your a/f ratio depending on the type of header that you are getting. Certain headers alter exhaust flow in such a manner that it upsets the 02s percieved reading. This usually ends up in the car running slightly richer than before.
14.8 for maximum efficiency and emmissions while just cruising around in part throttle conditions
12.3-12.8 for maximum power. This is your WOT a/f ratio
Headers, will affect your a/f ratio depending on the type of header that you are getting. Certain headers alter exhaust flow in such a manner that it upsets the 02s percieved reading. This usually ends up in the car running slightly richer than before.
Re: What is the proper air/fuel ratio? You say headers will richen it up. does that mean at WOT the number will be higher or lower? I'm getting a set of TPIS headers. Right now I'm at 332rwhp/352rwtq with an A/F ratio of about 12.5. Can anyone explain more about a MAFT. How do you read your A/F with a MAFT? I got the previous A/F number from when I was on the dyno. Do you need Autotap to read your MAFT? Any answers will be helpful. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />
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Re: What is the proper air/fuel ratio? Headers lean you out causing your LTFTs to go to a positive number, but that positive percentage is added at WOT resulting in a rich condition at WOT. When you richen your LTFTs to a slightly negative number, you will lean out WOT at the same time.
You need to scan your car before you can know how to adjust the MAFT. By using the base setting on the MAFT, get your LTFTs slightly negative, then adjust your WOT a/f ratio. If you use a scan tool like EASE, you can adjust WOT very accurately (without a wide-band) by watching DELTORQ (delivered torque). The highest torque number is how you determine what the best O2 reading is, and that might not fit into standard .89 to .91 O2 readings; It might be .94 instead.
You need to scan your car before you can know how to adjust the MAFT. By using the base setting on the MAFT, get your LTFTs slightly negative, then adjust your WOT a/f ratio. If you use a scan tool like EASE, you can adjust WOT very accurately (without a wide-band) by watching DELTORQ (delivered torque). The highest torque number is how you determine what the best O2 reading is, and that might not fit into standard .89 to .91 O2 readings; It might be .94 instead.
