Difference between auto and manual a/f ratios
Thread Starter
Senior Member
Joined: Feb 2002
Posts: 122
Likes: 0
From: Raleigh, NC
Vehicle: 98 Tibby
Difference between auto and manual a/f ratios
Ok so I was setting some basic fuel corrections on the SAFC (for reference I have a 98 auto with I/E/BBTB + some other minor stuff) and was using the average dyno tuning corrections. So I set mine at
1000 = 0
2000 = 0
3000 = -2
4000 = -4
5000 = -6
5500 = -8
6000 = -10
6500 = -12
on high throttle with it set at 80% so the majority of the time (everything below 80% will be normal/stock). This makes sense because our cars tend to run pig rich at high rpms. My question is: would the autos have the same fuel maps and run so rich? I think I remember seeing a dyno with a/f ratio for a stock auto and it actually seemed to run lean at high rpms. Can anyone give some insight on this? I am going to get it dyno tuned once I get some more mods but as curious in the mean time.
1000 = 0
2000 = 0
3000 = -2
4000 = -4
5000 = -6
5500 = -8
6000 = -10
6500 = -12
on high throttle with it set at 80% so the majority of the time (everything below 80% will be normal/stock). This makes sense because our cars tend to run pig rich at high rpms. My question is: would the autos have the same fuel maps and run so rich? I think I remember seeing a dyno with a/f ratio for a stock auto and it actually seemed to run lean at high rpms. Can anyone give some insight on this? I am going to get it dyno tuned once I get some more mods but as curious in the mean time.
Administrator
Joined: May 2001
Posts: 23,226
Likes: 9
From: Upstate NY
Vehicle: 2010 Genesis 2.0T
The auto and manual should both run RICH at WOT, regardless of RPM. I seriously doubt the A/F readings between manual and auto would differ significantly for 2 cars with the same mods.
Moderator
Joined: Feb 2009
Posts: 11,732
Likes: 5
From: Leesville, Louisiana
Vehicle: 2001 Hyundai Tiburon
The AF ratio should not be different. The only difference between the Manual and Auto is the transmission itself. Even the manual has a transmission control unit which is used for cruise control.