Air/Fuel Ratio - Third Generation F-Body Message Boards

89_RS_Mike · 01-20-2002, 04:36 PM

What should the air/fuel ratio be? My http://www.nordskogperformance.com guage says that Stoich is 14.7/1. Is this true?

86TpiTransAm · 01-20-2002, 04:49 PM

I've heard between 12.7:1 and 14.7:1

doc · 01-20-2002, 06:47 PM

Yes, the perfect air/fuel ratio is 14.7:1

However, the fuel never gets mixed in perfectly to burn all of the oxygen. Therefore, typically you need to run a little rich to burn all of the oxygen to develop max torque and Hp. So you should be running between 12.7 and 13.3:1 for best WOT performance.

For normal cruising around, 14.7:1 is just fine for better fuel economy, even leaner like 15.5:1 is OK.

Grumpy · 01-22-2002, 01:04 PM

Quote:

Originally posted by 89_RS_Mike
What should the air/fuel ratio be? My http://www.nordskogperformance.com guage says that Stoich is 14.7/1. Is this true?

For idle, and cruise 14.7 is dandy.
If you want a lean cruise of like mid 16s will get you better mileage.
WOT tuning is about finding what your engine combo wants.

BTW, the oem ecm toggles the AFR so that the AVERAGE is 14.7. I has to cycle rich and lean to keep the converter working