Norfolkluegojnr
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| posted on 25/4/15 at 05:38 PM |
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AFR Ratio -what sould I be looking for?
The work continues in the vain hope of getting to stoneleigh next weekend in the Gemini.
Ok, I've got my wideband installed at last, and initial readings were very lean - idling at around 16.5:1.
Fiddled with the idle screws, and got the idle down to 14:1 /14.5:1
On the move, I'm cruising at around 13.5:1, but it does fluctuate between 13:1 at the lowest (cruise at low revs in high gear) to 14.5:1
(booting it any gear, high revs) It goes, well although I am getting a bit of popping on the over run (i presume when it runs lean with the throttle
shut).
So, what am I looking for ideally, what AFR at idle, at part throttle and and what at WOT? and is it normal for AFR to fluctuate that much? Idle seems
better since I retarded the ignition slightly, and the temps are much better having relocated the rad, and removed the grill.
Just to recap, its a crossflow on ZZR600 bike carbs.
Thanks as always (feeling like i MIGHT make it......)
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alex1991
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| posted on 25/4/15 at 06:00 PM |
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I've only ever tuned injected Honda engines.
I idled mine a little leaner around 15 purely for petrol savings. The leaner the hotter it will run though.
I could run my engine lean at part throttle, usually around 16 to 17. For an older car I would aim just above stoichiometric (15-16).
For WOT its better to run richer than stoichiometric, 12.8 to 13.2 was the happy medium. But this depends on ignition and compression.
If you are turbocharged go even richer.
All this is from Honda engines so I don't know of how much use it is to you.
Firstly I assume you have calibrated your wideband?
[Edited on 25/4/15 by alex1991]
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dave_424
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| posted on 25/4/15 at 08:11 PM |
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Not sure about your specific application but from what I've seen the general rule is 14.7 at idle, around 15-16 on cruise, light throttle
acceleration around 13-14, Full throttle 12.5 is the magic number
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