Battery Voltage Correction(ms/V)

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titi
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Joined: Sun Apr 17, 2016 11:19 pm

Battery Voltage Correction(ms/V)

Post by titi »

Hi, I have a question about how work the parameter ''Battery Voltage Correction(ms/V)'' in the dead time calculation ?
Because in my case when I decrement this value, my AFR is going down (rich) and when I increment this value my AFR is going up (lean).
I dont really undertsand what is the real calcul with this parameter.
It is not an add to dead time ?
Thanks
slow_hemi6
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Re: Battery Voltage Correction(ms/V)

Post by slow_hemi6 »

As voltage drops it is expected that the injector will take longer to open. The opposite is also true that if supply voltage increases the the injector should open quicker. This value is the compensation for that. The base injector dead time is set @ 13.2V. If the injector supply voltage was to drop to 12.2V the standard 0.2mS/V would extend the pulsewidth by 0.2mS for that 1V drop. This should then maintain the same AFR if the injectors are supplied with a voltage that varies. Both the dead time and the correction have to be accurate to get a good result.
Find the Manuals up top under Quick links: Manuals. :RTFM:
Cheers Luke
titi
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Posts: 30
Joined: Sun Apr 17, 2016 11:19 pm

Re: Battery Voltage Correction(ms/V)

Post by titi »

Ok
With this injectors : http://www.siemensdeka.com/product/42lb ... 1420-48mm/
what is the value I need to fill ?
because it 's not the same value if voltage increment or decrement ?
and it's not really a straight line but a curve.
Blown88GT
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Re: Battery Voltage Correction(ms/V)

Post by Blown88GT »

Values you seek must be calculated.
https://docs.google.com/spreadsheets/d/ ... =302838282
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titi
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Joined: Sun Apr 17, 2016 11:19 pm

Re: Battery Voltage Correction(ms/V)

Post by titi »

Blown88GT wrote:Values you seek must be calculated.
https://docs.google.com/spreadsheets/d/ ... =302838282

Nice. .
Thanks
cygnusx1
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Re: Battery Voltage Correction(ms/V)

Post by cygnusx1 »

I turn on and off all electrical loads and observe PW change and AFR change. Keep adjusting the Ms/V until AFR is stable. Not sure it's entirely perfect, but it seems to work.

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slow_hemi6
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Re: Battery Voltage Correction(ms/V)

Post by slow_hemi6 »

cygnusx1 wrote:I turn on and off all electrical loads and observe PW change and AFR change. Keep adjusting the Ms/V until AFR is stable. Not sure it's entirely perfect, but it seems to work.

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Others do the same without alternator charging, and then with alternator charging. That can provide a larger voltage drop. More work though.
Find the Manuals up top under Quick links: Manuals. :RTFM:
Cheers Luke
titi
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Re: Battery Voltage Correction(ms/V)

Post by titi »

It is not easier to have a dead time table instead of this values ?
I think yes
slow_hemi6
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Re: Battery Voltage Correction(ms/V)

Post by slow_hemi6 »

So that is a good reason to move to the more powerful MS3.
Find the Manuals up top under Quick links: Manuals. :RTFM:
Cheers Luke
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