If you have ever sat next to or rode in a big truck, like the Gavril T-Series, when the truck takes off, the fan starts spinning at a higher rpm to cool the engine. It would be cool if they also had both types of fans. "Direct"(Spinning the same speed as the engine.), and "Thermostat Style"(Spinning at the speed needed to cool the engine. Turns on/off by its self. Ran on a large DC motor.) If this could be added I think the semi would sound alot better and be much more realistic.
There is a mod for that, as far as I know. https://www.beamng.com/threads/better-sounds-mod-4-3-work-with-0-11-0-5.38669/
Mod has radiator fan playing quite loud and very low frequency compared to what I have heard those IRL. Official implementation would probably be better and certainly it would add more immersion. Vehicles with mechanical fans would especially benefit from added fan sound as it is very important part of soundscape of such vehicle.
Yes, a mechanical fan would be great. If they had it where the engine heated up faster in warm areas and slower in cold or windy conditions. The steady on/off in the Utah map when idling or driving would be great for the T-series. --- Post updated --- The forum deleted my response. Huh. Anyhow, I had said "Yes a mechanical fan would be nice. If they got it where in warmer climates the engine would warm up faster than in cold or windy conditions, the fans would turn on and off more. This would be cool for something like the Gavril T-series driving or idling.
Most clutch fans don't ever acheive full lockout, but more like 70% or 90% in a severe duty model, so it's not 1 to 1 with the water pump per se. And it still draws when in disengaged mode at about 20 to 30%. They certainly rob more horsepower than electric fans do, so that should be taken into account as well. Plus the option to maybe convert to electric on older motors could very well give you a 5 to 25 peak hp boost due to reduced resistance. Would just draw a little more from the alternator which isn't simulated yet. Or possibly never, I guess.
So the clutch fans can be turned off? Sorry, I'm not extremly mechanicaly bright. What I meant for the electronic/mechanical fan is on the highway or on hills the fans turn on and off alot becuase of the heat produced by the engine and outside temperature effects. The MAZ bus mod is a good mod that shows this. It has the fan sound and tire on highway sounds.
In a sense, they do have a lower draw mode, or "disengaged" but it still spins at about 20 to 30% of the speed of the water pump. So there is still some resistance. Under heavy throttle/heat application, they'll be far closer to 1 to 1 with a severe duty clutch, but not quite. More like 90% the speed of the water pump. Or 70% with a standard duty clutch. But the clutch fan is far better than if you were to get a clutchless mechanically driven fan, but when you really give it yhe beans and need that extra power, you still lose almost as much when it gets to "fullish lockout".
--- Post updated --- Hopefully Beamng can add this realisim to the T series. Thanks for that info! Do you know of how to contact them for suggestions?
Some mechanical fans have viscous coupling clutch, which has faster and slower operation. Some mechanical fans have direct connection. Electric fans have also sometimes high and low operating mode.