How much (Amps) does a TBI system pull on average?

[MuddiGGEr25]

I am trying to figure some calculations for possibly upgrading the alternator for a 1994 5.7L TBI/4L80E combo i will be installing into my RV in about 5 weeks.

I know at idle that a TBI engine will draw XX amps and that will increase as the engine load is increase (towing/accelerating)

What i need to know is an average amperage draw say if i was going 55mph or turning 2000RPM on the highway...

I know the general rule of thumb for a battery label on "reserve capacity" is either 20A draw or 25A draw until the battery reaches 10.8V which at that point the S.O.C. is 0%

I need to know how many A will be available after the computer/injection system takes what it needs because in the RV i have a 5AWG wire running all the way to the rear compartment where i have 1 8D battery for reserve start capacity, and 2 AGM solar sealed 125Ah batteries. and 15-24A coming in from the roof mounted solar system., any excess is then sent to the 8D battery via battery isolator, and once that is full then the rest is dissipated in heat. 

I intend to run the grid tie inverter off the battery bank while driving which will be constantly charged via alternator and solar and alternator only if it is inclement weather.


I know at best case idle i will only have 85 out of the 105A maximum capacity at hwy cruise (yes i also know its not generally a good idea to run an Alternator at 100% capacity unless i intend to replace it)

i have attached the power curve for an OE 100A and 105A CS130 alternator (please remember the shaft speed will be approx 3x my crank speed due to pulley sizes)

at engine idle ~800rpm i am around 2100-2400rpm alt shaft which would give about 70-75A gross, and at 2000rpm highway shaft speed would be around 6K with output at pretty much maximum of 105A.


I just want to run the window A/C (8A when on max, 6A when on eco) and keep the fridge plugged in

the entire rig will be LED inside and out by the time harvest is over, the only lights that will draw significant power are the stove, headlights and driving lights.

Radio is rated for 50W per channel max.

Would also like to know idle draw incase i decide to idle it to rejuice the batteries if its incliment weather for several days in a row

[MuddiGGEr25]

anybody?

[Irish_Alley]

im not sure any of us can tell you. it seams you have more knowledge on electrical things, but from what i can understand and see on my 91 with a 350 4l80e/205 crew cab theres only 2 fuses for the ecm 1 and 2 both are 10 amp. so i would think that max ecm pull would be 20 but i dont think they run at max so 10-15 amp???

[MuddiGGEr25]

Kinda what i was figuring lol, i think im gonna have to install my Multimeter across one of the ECM fuses (special adapter) and just monitor it as i am driving to get a guesstimate, its not super urgent though as i have about 5 weeks before the swap