Air/Fuel ratio, is there a quick answer? |
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Air/Fuel ratio, is there a quick answer? |
malcolm2 |
Feb 5 2017, 05:50 PM
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#1
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Advanced Member Group: Members Posts: 2,745 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States |
OK, I have been tinkering with the new-to-me AFM on my 1911cc engine all weekend. I have adjusted the spring about 20 teeth CCW to get to this point.
I have been using an A/F sensor and gauge. can someone tell me, or direct me to a chart/table of what A/F I should be shooting for on my daily driver. The last adjustment of the CO screw has left me here: I have always had a strange idle situation, so lets ignore that for now. any normal adjustments to reduce the idle at normal operating temp eventually stall the car. A problem for another post. (IMG:style_emoticons/default/blink.gif) the idle is high.... at 1200 the A/F is a smooth 12.2. I found a long hill and drove up it at about 3800 rpm and the A/F was 12.5. thoughts? |
falcor75 |
Feb 10 2017, 01:34 AM
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#2
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Senior Member Group: Members Posts: 1,579 Joined: 22-November 12 From: Sweden Member No.: 15,176 Region Association: Scandinavia |
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djway |
Feb 10 2017, 04:07 AM
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#3
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Senior Member Group: Members Posts: 787 Joined: 16-October 15 From: Riverside Member No.: 19,266 Region Association: Southern California |
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Mark Henry |
Feb 10 2017, 10:03 AM
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#4
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
If you are running at stoich AFR on an aircooled you're cooking your heads. (IMG:style_emoticons/default/rolleyes.gif)
Buy a decent head temp gauge and see for yourself. Decel AFR is useless info, stop obsessing on it, it doesn't matter because there is no load on the engine. AFR has no bearing on mechanical braking load. As I said my FI system cuts all fuel at TPS zero on decel (except for idle between 800-1200rpm*) that's no fuel you can't get much leaner than that. AFR is important under load, WOT, hills, cruise, etc. WOT 12.5, nickies you can be just over 13:1 Cruise 13 to 13.5 max I aim for just over 13:1, nickies you can run up to 14:1 Hills basicly the same as WOT, maybe a hair more. * IIRC I'd have to check my program to see the range and my car is in storage, but 800-1200 is close enough. |
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