[BUG] Torque "pulsates" on some drivetrain/engine configurations

[CheezusChrust]

Short Description

For as long as I've used ACF, I've constantly encountered a bug where torque seems to pulsate on and off as I accelerate, depending on the vehicle's drivetrain configuration, and what type of vehicle it is. The best description I can give is that it feels like I'll get a burst of torque to the wheels, and then the gearbox acts as if it's clutched for a second, delivering zero torque, and then I get another burst.

How to Reproduce (Optional)

I haven't found a way to perfectly reproduce this yet but I notice it happens on tanks with complicated drivetrains, and on almost every RWD/FWD vehicle I make to some degree.

Video

https://streamable.com/4wgxnb (the brief wheel spazzes are a symptom of this, not the cause)

Additional Information (Optional)

This problem is occasionally fixed by placing a differential between the engine(s) and primary gearbox, with ratios of 1/1. I don't have a 100% success rate with doing this though.

[CheezusChrust]

Better video of it happening - in the top right, I'm printing Link.ReqTq from the gearbox connected to the engine (added print(Ent, Link.ReqTq) after line 604 in entities/acf_engine/init.lua)

https://streamable.com/nt6stg

In the middle of the video, I shift into a high gear and turn hard. The torque seems to become consistent when the engine is under very high load and stuck at near idle RPM. Throttle is 100% the entire time. At the end, I slowly accelerate forwards in a high gear and the pulsating behavior becomes extremely noticeable.

The dupe used in the video