I always ask the question, Is there a mixture knob in a modern car? Long gone are the days of carburetors.
With EFI computers, they use a table (RPM vs MAP) to indicate which AFR to target. Megasquirt does an excellent job of this. Once you get your engine's volumetric efficiency table dialed in, all you have to do is change your AFR and MS will calculate your fueling to reach that AFR.
- Matt Boiteau
On 2018-09-18 11:27:40 AM, Ernest Christley echristley@att.net <flyrotary@lancaironline.net> wrote:
On Monday, September 17, 2018 11:56 PM, "Matt Boiteau mattboiteau@gmail.com" <flyrotary@lancaironline.net> wrote:
And I still haven’t been convinced of a mixture knob. Let the ECU talk with the wideband & baro and do the work for you.
For mixture, one of the things you have to keep in mind is that there are situations where you'll want different mixtures that the computer can't know about. For example, you want to go full rich on take off and landing, but lean out for cruise. How will the computer know what is appropriate at which time?
I got around it by adding a pot to my throttle control and used it as the throttle position sensor. The first half of travel controlled the throttle body cable, and the mixture was tuned lean until the throttle was completely open. The second half of the control lever travel increased the amount of fuel in the mixture, with it topping out at about 12:1.