Alpha N and map multiplier

[killerbee]

Hi
Yesterday I've tried to switch from Alpha N to Alpha N + map multiplier , I've setted TPS vs MAP table to 100% in all cells . Then start the car and see that MAP changes fueling a lot , why is that , mustn't it be as alpha N when this table is 100 % ? I thought to set it 0 but lowest number is 25 ... I read the manual :

ALPHA N PW = INJ_CONST * VE(tps,rpm) * AirDensity * Corrections + AccEnrich + InjOpeningTime
ALPHA N WITH MULTIPLIER PW = INJ_CONST * VE(tps,rpm) * MAP * AirDensity * Corrections + AccEnrich + InjOpeningTime

So my car will run as ALPHA N only at 100kpa , in lower kpa the fuel will be less - 50kpa 50% less fuel ... but if I put value of 200 in TPS TO MAP it will be OK ...... or I am mistaken ?

[Jadzwin]

Alpha N with MAP multiplicaion is quite similar to speed density but the load is defined by TPS.

Why do you need to use such fuelling strategy ?

[killerbee]

Because the car is almost finished with alpha N , now I see that in some low tps driving situations it is a problem - downhill uphill and so , so I want to turn on this map multiplier and start tuning this situations , but whenever it is changed the car dies ... as I understant it can not be as alpha N and I must tune it from beggining

[Jadzwin]

try to use TPS vs MAP correction table.

If you want use MAP mult. you need to retune the whole table.

[killerbee]

So I can use TPS vs MAP table in alpha N mode ??? It will be cool not to use Alpha N wit map multiplier , but to use this table - in what units is this table % of fuel ( 100 units are 100% fuel like it is , 50% will half fuel ) ???

[Jadzwin]

Yes you can use it. And this is just a fuel scale so 100% means no change 110 is 10% more of calculated fuel and so on.

[killerbee]

Perfect , thank you