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Title: Best Air Fuel ratios? Post by: dokalanyi on July 29, 2017, 01:34:11 AM So I've been a long time VAG owner (1.8T), and all my tuning knowledge is acquired from here, and most of the AFRs are in the 13s when rich. I think the richest AFRs are 12s (especially Stage 1) here. However, I recently checked out Subaru ROMs (even recommended stage 1 AFRs), and even factory tunes are as rich as 8.8:1. I've attached stock fueling for an 01 Impreza STI. Why do they have to run so rich, or how are we able to run so lean?
Title: Re: Best Air Fuel ratios? Post by: _nameless on July 29, 2017, 05:19:59 AM do you realize subaru are 10.5:1 compression and pistons are shitty cast
Title: Re: Best Air Fuel ratios? Post by: _nameless on July 29, 2017, 05:22:16 AM our cars are on avrage are a whole point or more lower compression, we have forged pistons and our kr is night and day better then that denzo junk
Title: Re: Best Air Fuel ratios? Post by: dokalanyi on July 30, 2017, 09:41:09 PM I guess that pretty much sums it up
Title: Re: Best Air Fuel ratios? Post by: RBPE on July 31, 2017, 10:13:20 AM Not just that though, manifold/port/piston/cylinder design, spark energy/efficiency/placement, tumble effect/atomisation, material structure and resilience, fuel/reactant and, most importantly - evolution of the control systems, all have a say on where proper deflagration comes - hence why people say log! ;)
https://en.wikipedia.org/wiki/Deflagration https://en.wikipedia.org/wiki/Thermodynamics https://en.wikipedia.org/wiki/Analytical_dynamics https://en.wikipedia.org/wiki/Law_of_mass_action Title: Re: Best Air Fuel ratios? Post by: jcsbanks on August 01, 2017, 04:13:08 PM Subarus of that era are usually about 8:1 compression.
The AFR ratios displayed in some of their maps are misleading like here. Some areas are not hit, and others that are don't run as rich as they appear as they are not closed loop wideband controlled and sometimes the primary fuel map is not the one shown as such. They often run in the 10s:1 AFR though. I learned on them back in 2000. I still don't like them. |