Do you have any data? I do use one. I've never seen the playback show RPM go over the setting by any noticeable margin during a drivetrain failure.
Doug

It would depend on what RPM range you run I guess. Probably a non issue with a 6800 rpm combo but a concern with a 9500 combo.

My engine guy does a lot of hydroplane engines that run in the mid 7000 range and the Racepak shows an instant spike to upwards of 10,000 every time the prop comes out of the water. Apples and oranges difference in applications I admit.

Kevin

It’s not inertia that does this. Inertia keeps things either at a standstill or a constant speed.
By a stretch it could be called kinetic energy

I’m betting you will find that it is caused by “fire in the holes”.
Fuel fed to the engine to maintain or accelerate under a given load (launching the car or in a burnout) then all of s sudden the load disappears.

Physics class was a LOOONNNGGG time ago so probably using the wrong name for the property. Stored kinetic or potential energy? Same principle that if you are going down the freeway at 75 mph and lose a wheel, causes the wheel to accelerate past you and disappear.

Kevin

Me thinks the increase drag on the car brake drum or disc rotor rubbing or dragging on the road, causes the car to slow down and let the wheel and tire go at the same speed as it came off of the vehicle

I once lost a tire on a vehicle in tow. In the rear-view I saw the tire go off into the next lane and trail far behind me. Then another car ran straight over it with the tire upright the whole time. It was like the car went over a jump. It was a terrible thing to watch, but the tire never went ahead of the vehicle, I can tell you that. I remember the incident vividly. Nobody was hurt, fortunately, but the car that drove over the tire was totaled