# Engine combos

As part of the overhaul of vehicle code you can currently only have one active engine at once. I’d like to remove this restriction and add some functionality we’ve been missing all along. For example a foot pedals and traction engine is silly but a tandem bicycle would be interesting.

What combinations are most interesting and how should they work? For example now we have NPC seat allocation a rowing boat is a realistic possibility? Note you need to consider that people could define some fairly exotic engines now that everything is in JSON so when making suggestions think about all the possible interactions. For example how would boat sails work with a jet engine?

Gloriously…

More seriously though, you’d probably have designate when other sources of propulsion become negligible in their contribution and disregard them or something. In the case of things like jet engines and boat sails or ripping down the road in your combo peddle/V8 powered muscle car.

The jet engine and sail would work at cross-purposes. As the jet engine accelerated the vehicle, the sail would cause drag in an atmosphere as long as it remains fixed to the vehicle. Eventually the sail would be torn from the vehicle.

Jet engines are at best a 0.D thing, for now just focus on getting the old functionality back up.

shit!!! my hybrid propulsion system - like on toyota hybrid - cry… my apocalibus!!!
i have four 1LV bike motors which run on generators from trucks and to electromotor-wheel on the each bridge (my apocalibus have 8 axis like in TOPOL-M) and all my roof covered with solar panels…

and all goes to cat’s under his tail…

i think what to calculate average power of many heat-engines not so untrivial task.
there is formula of calc volume to power. if we take constant compression value and RPM’s - we have linear dependency from volume of motor, volume = power. we get power of each motor. in many-motor-car we may automatically need of install motor-wheels and only motor-wheels electro-transmission. and so - all motors may job at one time - many motor = quicklier charge of accums no matter is a bipedal bike transmission or gasoline motor or diesel motor - not matters. and all will be work at a one time.

and what say you your friend from car-building college? did he not give you formula to convert volume to heat-power?
need to get all power and convert it to electricity and transfer to motor-wheels and all will be ok. dumbly add all power of all motors multiply to “koefficient of greed” and voila. its simply.

BTW i remember about gear train (GT)
all motors may work at one time with correct GT.

and - devs not say which problem he receive from many-engine cars.

The existing code was written for single engines then at some point extended (very badly) to allow multiple. It’s heavily dependent upon global state, almost entirely undocumented and with a lot of outstanding bugs which are hard to fix given the state of the code. Additionally most of the values are hardcoded which has lead to some nasty hacks in mods which only worsens the problem.

The goal of this thread is to identify corner-cases and possible implementations for them.

as far as i understand you - you mean what this way of multi-engine is buggy at all and sometimes may be bad ends, yes?
hmm. thanks for explaining.

hehe btw i have car with three drives on -
gas motor
electro motor
and bike bipedal gear

how it ONed all - i do not understood self. but it fact.
GAS endine run electro engine works and i roll pedals

i hope as well that sometime multiple engines is doable, heck, maybe even hybrid electric-(misc)fuel type vehicles where the electric engines work in tandem with the conventionals, i typically would build with an electric, diesel and gas engine whenever possible, sometimes i don’t need the horsepower to smash down buildings and just run the basic electrics after all.

I have two scenarios where I run multiple engines:

1. Large vehicles or foldable engines
a) Tanks and other huge vehicles that need multiple engines just to move.
b) Foldable vehicles where each engine is very weak and I need many engines just to move
2. Redundancy and extra power
My typical deathmobile has a diesel V8 and a large electric motor that I almost always run separately but will occasionally use together to get extra acceleration in an emergency.

The multiple folding engine problem is probably the biggest concern for me.