Off throttle AFR?

[ateick]

Wondering what would people suggest for AFR coming hard off the throttle to o% TPS?
Currently seeing 12.0 but I think this might be a bit rich. Thinking 13. 14 would likely create some unwanted backfires.

Hurricane 190 kit installed.
Cheers

 

[mbarryracing]

Actually in my experience with my Apex my backfires after chopping the throttle closed were a result of over fueling / rich AFR's during decel after chopping the throttle closed to 0% with a hot exhaust. When decel AFR's are lean there isn't enough fuel to light in the hot exhaust...
The leaner the better, just wasting fuel by dumping it out the exhaust under decel anyhow.

 

[ateick]

Thanks mbarryracing.

Looks like from your info and others articles I have read that very lean or very rich can cause decel popping. The best thing to do I guess is play with the numbers a bit and pull back if popping starts to happen. I'm going to go leaner than the 12.0 I have now to try to economize fuel. I'm thinking 14.0 range.

 

[mbarryracing]

My Apex back fire popped every time I let off the throttle while cruising and at night you could see it belch flames. AFR was 11 to 12 under a decel. I leaned my fuel out at 0% throttle 2500 RPM and above to try to target 14 to 15 and no more popping or flame throwing... Also gained some on my fuel mileage a bit too. Some OEM's turn the fuel off completely during a 0% throttle decel.
Think about it... No fuel to combust in the hot exhaust...