Making a FWD car AWD

Hi all,

I'm new to this forum.
Anyway, I've been trying to use this tutorial https://www.beamng.com/threads/tutorial-vehicle-performance-and-components-modification-simple.4261/ to make the New Pessima AWD instead of the original FWD.

So I've got the rear differential showing up under the independent rear suspension, and I can select either Open Rear Differential or Limited Slip Rear Differential. If i select Open Rear Differential, I get a lot of wheel spin from the front wheels, but it seems that no power gets to the rear wheels. If I select Limited Slip Rear Differential, i still get no power to the rear wheels, unless I make the Rear Half Shaft empty. But, if I make the rear half shaft empty, The car does send power to the rear wheels, but starts accelerating at an extreme rate and at times the rear wheels explode and fly off of the car.

I'm not sure what to do about this... Any help would be appreciated.. I'm sure I probably did something wrong in the differential jbeam, although I'm unsure. I'll attach my rear differential jbeam file.

 

Did you give it an AWD transfercase?

 

I think so. Which jbeam is that in?

 

The tutorial you used is severely outdated, adding differentials isn't enough. Since version 0.8 you have to define the entire powertrain piece by piece. First you need a transfercase - you can copy it from the sunburst or one of the etks. I recommend making a custom transmission with the transfercase slot (just copy one of the stock ones and add the slot to it). Then you need a custom front differential, since the stock one is connected directly to the transmission and you need it to connect to the transfercase instead. To do this, copy the stock one, then in the "powertrain" section of the jbeam change "gearbox" to "transfercase". Next you need a driveshaft - again you can copy it from some other car, but make sure the input is set to transfercase and the input index (the number next to the input name) is different from the front differential - usually the front differential will be 1 and the driveshaft 2. Next is the rear differential. You can use the one you already made but you need to change the input to the driveshaft. I would also remove the "flexbodies", "torsionreactor"(also remove it from the inputs), "nodes" and "beams" sections from all the parts except the transmission and front differential - because most of the added parts are copied from other cars they won't line up properly and can even break themselves due to weird collisions. Removing the aforementioned sections makes the parts exist only in code, which is enough for the powertrain to work. This makes the powertrain less realistic, but you don't have to go through the trouble of modelling and jbeaming all the added parts.

You can also use this awd conversion I threw together some time ago. It's not very realistic and slightly outdated, but it works.