EFI questions and answers

[peter paul fenske]

>Hi Todd: Just 2 cents: Peter
>tried calculating a function using the SAE correction factors for 
>horsepower, because they use air temp as a function and these come alot 
>closer to the factory compensations, but are still no the same.  
>>
>>Use a Wot corrector table indexed against temp. Add this to
>>ur base pulse
>>
>	Air temp compensation at idle doesn't seem to be the same as at 
>part throttle or full throttle conditions either, why and how do you 
>compensate for this.
>>
>> Use a second temp corrector table in Idle loop
>>
>2.	Idle compensation.  The closed loop idle compensation function 
>Porsche had used on this unit worked pretty good for the Air Flow type 
>system, but surges like crazy with the speed density system.  Does 
>anyone have any good examples of closed loop idle comp. functions or PID 
>loop stuff I could try, or maybe a fix for the Motronics one.
>> Use an error to speed corrector table. Set is up so the greater
>>the difference between desired idle speed and actual rpm the faster
>>the idle motor responds. When you are close adjustment should be slower
>>
>3.	Barometric pressure compensation.  Why do you need to compensate 
>for BP when if you are using an absolute BP sensor.  I can understand 
>the stoichiometric thing about high altitude vs low altitude and if it 
>is part or full throttle, but who cares on a performance application, or 
>let closed loop figure that one out.  Will the calc's be correct on a 
>system that was designed to run, say, 13.0 / 1 air fuel ratio all the 
>time, no matter what the condition.  Would the air fuel ratio change at 
>different altitudes?
>
>>Well with key first on, engine not running take a Map reading.
>>Use this as your BPC. Effects are neg unless you live in Colorado.
>>
 knighton at concentric.net
>
>Well GL: peter