Accelerometer is Not Acceleration?

I use acceleration in unreal engine and it goes only forwards but is accurate using real world speed and seeing differences in speed, so I ghost race and the faster time wins.

But I could only go forwards, and it only goes right, and if you go negative they cancel each other or it goes left.

Now, I switched to Unity thinking it had a solution, but it’s accelerometer input is basically only tilt, not real acceleration.

So Unreal somehow has acceleration, true acceleration, but it only works forwards or only right or only left, and if you jump it has no effect on the z-axis but I’m not sure if the gyroscope or accelerometer can tell your going up in the air, I think it can, it can calculate altitude on the Recon Jet. But it cannot or does not affect the z-axis if you jump.

Also it increases speed exponentially. The faster you go, the more distance you cover in that world in unreal engine’s world. That’s fine makes sense. But I walked the distance and it took me halfway across the path I was on, then I ran it faster and faster, and the faster I ran, the less distance I had to cover. It makes sense but makes no sense at the same time. My beginning time of 9 seconds was halfway across the path, my 5 second time was 1/4 of that. my 1.54 second time was like 1/10 of the distance. So acceleration doesn’t equal distance? Or? I don’t know. It’s confusing.

But it does get acceleration and it works so I’m thankful for that, since it’s not possible in Unity. Just weird kinks in it.