Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - What is the relationship between lean burn, timing and octane?

rmay635703 · 10-17-2015, 05:07 PM

In my application the motor always runs WOT at around stoich, I am attempting to improve this by nudging the AFR somewhere between 15-16:1 AFR

The motor calls for premium and only runs WOT but at a variety of RPMs from 1200-3600rpm.

Based on what you are stating to move to peak heat I will need to keep a similar or higher octane (calls for 91, will likely need 93 or 91 with more ethanol)
and may also need water injection of some type.

I wanted to combine this with a hot air intake since I am running the motor lightly loaded (only in terms of peak output at peak RPM) but based on what you state this will possibly cause knock and again possibly require water injection.

Ah well, if I ever get off my arse we will see how this works, maybe start with hot intake (WAI) and leave AFR alone.

Cheers
Ryan

10-17-2015, 05:07 PM	#4 (permalink)
rmay635703 home of the odd vehicles Join Date: Jun 2008 Location: Somewhere in WI Posts: 3,891 Silver - '10 Chevy Cobalt XFE Thanks: 506 Thanked 867 Times in 654 Posts	In my application the motor always runs WOT at around stoich, I am attempting to improve this by nudging the AFR somewhere between 15-16:1 AFR The motor calls for premium and only runs WOT but at a variety of RPMs from 1200-3600rpm. Based on what you are stating to move to peak heat I will need to keep a similar or higher octane (calls for 91, will likely need 93 or 91 with more ethanol) and may also need water injection of some type. I wanted to combine this with a hot air intake since I am running the motor lightly loaded (only in terms of peak output at peak RPM) but based on what you state this will possibly cause knock and again possibly require water injection. Ah well, if I ever get off my arse we will see how this works, maybe start with hot intake (WAI) and leave AFR alone. Cheers Ryan