I have an LM1 AF meter. I ran it today using the new tailpipe adapter. I have the stock cat mid section and MagnaFlow Cat back. I know that you should take AF readings pre-cat, but have read and been told that you can use after cat readings but it will read about .5 lean. (i.e. a reading after cats of 13.0 is about 12.5 pre cats).
My 04 Cobra that runs an et of between 11.9 and 12.1 at 118 based on my 60 ft times and my AF was 10.6 at 6300 in 3rd and 4th. I use a predator and removed 15% of my fuel and still read about 10.6. I was confused and was asuming that the cats were the issue. I did a comparision with my friends 2000 Corvette and his readings were 12.5 and we leaned it 5% (also with a Predator) and the reading was 12.9. This proved that (with the Corvette anyway) that the meter and car is resonding to fuel changes.
I find it hard to believe that my car is that rich and running 118mph. I also find it hard to believe that removing 15% of the fuel parameter makes no difference in the Cobra , unless the Cobra Cats function different from the Chevy.
Any opininions or ideas?
My 04 Cobra that runs an et of between 11.9 and 12.1 at 118 based on my 60 ft times and my AF was 10.6 at 6300 in 3rd and 4th. I use a predator and removed 15% of my fuel and still read about 10.6. I was confused and was asuming that the cats were the issue. I did a comparision with my friends 2000 Corvette and his readings were 12.5 and we leaned it 5% (also with a Predator) and the reading was 12.9. This proved that (with the Corvette anyway) that the meter and car is resonding to fuel changes.
I find it hard to believe that my car is that rich and running 118mph. I also find it hard to believe that removing 15% of the fuel parameter makes no difference in the Cobra , unless the Cobra Cats function different from the Chevy.
Any opininions or ideas?
