Can someone please advise on these fuel tables

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Re: Can someone please advise on these fuel tables

Postby MWP » Thu Oct 07, 2010 11:11 pm

To enter closed-loop (EGO) mode:
- RPM must be over 1000, and under 3000
- Load must be less than 10"Hg
- Throttle position must be less than 25%
- Throttle position must have been in the same place (+- a few %) for last 5sec
- Coolant temp must be above 70degC

When in closed-loop, fueling is based on EGO reading alone.
Oh, maybe with one or two correction maps like batt voltage.

Thats a rough example.
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Re: Can someone please advise on these fuel tables

Postby tw2 » Fri Oct 08, 2010 5:15 am

Load is based on volumetric efficiency. So in the case of megasquirt: 100 means atmospheric ie 0 boost, everything below that is in vacuum. 200 means 1 bar of boost ie 14.7psi and 250 is around the highest boost i would ever run ie 22psi.

Lean cruise is based on load (and rpm to a degree). In my setup low load will put you into fuel cells which are fairly lean but it will get slightly richer if you are at low load and high rpm (ie waiting to waste some asshole going 20 below the speed limit), the fuel helps keep temperatures down at the higher rpm. It is not based on throttle position directly but obviously if the TB is open then you will no longer be at low load. Hope that helps. I am not using closed loop because I want to run leaner than 14.7 in places but otherwise as described above.
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Re: Can someone please advise on these fuel tables

Postby cozmic512 » Tue Oct 12, 2010 1:48 pm

Thanks, that helped a lot. I think I have a pretty good understanding of the table.
after checking it against a couple other tables (non MS) it looks ok
and nothing stands out as wrong or too far off.
I think that before a proper dyno tune, you really dont want to go too lean at any point.
because if there is a cell thats off, or the progression isnt gradual
theres the possibility of knock
or even having the cyl temps have a drastic change instantly.
because shit always happens on the road.
I personally run fairly rich over 25% throttle.
and lean cruise between 14.5-15.0 with a tune.
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