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Can somebody explain the difference between relative and absolute ALS retard mod

Started by black, July 30, 2015, 08:02:36 AM

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black

Can somebody please explain the difference between relative and absolute ALS Retard mode...??

If you have 22 deg of timing and absolute retard of 44 - the result will be -22 deg at max retard ...

but how will relative retard be calculated??

thx

VEMS

Hello Black,

Take a loot at VemsTune->Calc model->Spark it will show you the active contribution to spark advance of all functions, some help about it: http://vems.hu/vt/help/gauges/expression_grid.html.
In short when ALS retard active (see flag ALS activation for a indication, help: http://vems.hu/vt/help/v3/flags/isalsactive.html):

* ALS relative mode: retards current advance up to a max of current advance - max retard; so when current advance is 22 deg BTDC and relative retard (max) is 44 deg, then resulting timing will be between 22 deg BTDC and 22 deg ATDC (interpolated by tps/rpm).
* ALS absolute mode: retards from current advance up to a max static (absolute) timing ATDC of max retard; so when current advance is 22 deg BTDC and absolute retard (max) is 44 deg, then resulting timing will be between 22 deg BTDC and 44 deg ATDC (interpolated by tps/rpm).

Best regards, Dave

black

Hey thanks a lot...

... I use the calc model gauges very much in all calibrations - but I had a little issue to understand the spark ALS calculation...  now its clear...

I am using ALS with throttle kicker and getting 32% TPS when shifting...  ignition angle in shift is between -12 deg and faded out to -8 -2 etc...

so ALS ist working but there is no ALS effect in exhaust (no bäng)  :o