Hi all-


I know that the CO screw is a global modifier and adds or subtracts a percentage to or from the fuel table. Is this percentage equal at idle and at WOT? i.e. - What I mean is if I remove 1 unit say from 14afr at idle to 13afr at idle with this equally remove say 12afr at wot to 11afr?

Thanks for any info.

Best.

Tim.

 

No it actually changes the map sensor input voltage, it is best to set the CO pot to Zero pot position turn the co pot 5 turns in either direction then exactly two turns back.

 

Thanks- interesting, that said does this map sensor voltage input change effect fueling equally at idle and at wot?


Best.

Tim.

 

Another interesting question would be to ask- If I increased my fuel pressure from 3.5bar at 1 atmosphere to 4bar and leaned the engine back out to the 3.5bar value at idle using the co screw would the wot afr be the same as they were at 3.5bar?



Thanks.

Tim

 

No
Set the static fuel pressure to 3.8 bar and zero the co pot and asses the fuel curve you now have, do not try and tune your fueling via the co pot. I also suggest you check the intake system for air leaks either via the smoke method or pressure method. Check your fuel pressure rises directly proportional to boost

 

Thanks - Yes I understand the increase of fuel pressure will richen the fuel curve had a chip set-up running 4 bar to get the fuel required on 803's the lower end of the map was leaned out by the author of the chip.
Surely a wideband will let you know the effects adjusting the co has?


Thanks


Tim

 

The pressure sensor input signal is used by other tables in the ecu such as idle strategy and transient fuel correction

There is a lot of useful information for you to read and research here http://www.bigturbo.co.uk/ click on Maps

 

Thanks , will have a look.


Tim.

 

Interesting read - why have a co pot at all if its potential must be zero for other maps/strategies to work?


Thanks.

Tim