Don't know if this is the right place to post a suggestion like this
I would like to see some slip angle data in the replay analyzer.. This is some quite important data, so I don't know why it isn't already there!

Why is it THAT important? Don't you mean like a drift angle?

Let's say the optimum lateral slip angle of a tyre is 5 deg. Would it not be useful to see where you are exceeding it, thus losing time? You can also see where you're spinning the driven wheels too much in acceleration zones. Slip data isn't useless.

Yes, very useful for racing.. It would even be useful for you drift guys, the rear slip angle is basically the drift angle isn't it? Well I'm not sure about that, but I do know that rear slip > front slip = oversteer.

Bump.. I still think this is important
Do the devs read this section? =D

You can see slip angle in the various other telemetry analysers.

No other telemetry viewer does it as good as RAFA though
It would be a simple improvement to make.. Although I don't know if I am right about the calculation, isn't it just the dot product between where the wheels are turned (Wx,Wy,Wz) and where the vehicle is going aka. velocity (Vx,Vy,Vz)? That would give the cos of the slip angle. Math geeks come on

Does the RAF data contain a vector for wheel orientation like that? The most common standard for calculating slip angle would be Atan(vy/Abs(vx)) (where vx and vy are the velocity components of the wheel), but that is assuming that LFS isn't using some form of lag for smooth transitions, or any other adjustments for low speed driving (to prevent excess slip angles and the eventual divide by zero).

This is all perhaps unnecessary though, as I thought the slip angle was recorded directly in the RAF data.

Edit: No, I can't see it.

RAF data has a field for the front tire's slip angle (at least in f1perfview). To get the rear slip angle, you need to do some math with that and the steering angle. This can be accomplished by exporting the data from f1perfview to Excel.

I did this a while back and determined my peak slip angle on one hotlap was about 5 degrees, and I did it on nearly every corner. Might not sound like much, but that's in the FO8 @ SO4. Granted, my tire pressure was quite low, so that promoted high slip angles.

"Slip fraction" sounds very interesting, though.

"Slip fraction" from RAF is not slip angle. It's defined here (and in the RAF spec).

RAF does not contain slip angle directly. I am not sure if slip angle shown by F1PerfView is correct.

You can use my programs from this post to get slip angles (example). However, they are not very easy to use. Not that they are not user friendly, they are but in a geeky way. One factor that is not taken into account in the calculation is the movement (mainly lateral) of front wheel contact patches relative to car body due to steering input changes and caster (scrub radius also but its influence should be much smaller).

Slip fraction is actually very interesting.. So we can see if we exceed the maximum traction by looking at the forces in LFS? I did not know that
Also, there's something I'm not quite getting in the physics.. It seems that too high a slip angle does NOT cause lower lateral (cornering) ability of the tyre? But it still slows the car down? If so, how does this affect turning the steering wheel.. Does it mean that turning the steering wheel too much compared to the direction you are turning scrubs off speed, but does not cause less cornering ability?

Another addition, is this why most WR replays you see, are sliding so much? To me this seems like an exaggeration from the game's side, this would not be faster than some more traction IRL? I can't believe that. It's not "on the limit", it is beyond.

Quote from RasmusL :

It seems that too high a slip angle does NOT cause lower lateral (cornering) ability of the tyre? But it still slows the car down? If so, how does this affect turning the steering wheel.. Does it mean that turning the steering wheel too much compared to the direction you are turning scrubs off speed, but does not cause less cornering ability?

It is quite typical for the drop off after the peak on a slip angle vs lateral force curve to be very small.

There are two other points to consider though:
1) Increased tyre scrub will sap forward momentum
2) The lateral tyre force vector points more rearward the further you turn, meaning less of the lateral force is causing you to turn, and more of it is slowing you down

Quote from Bob Smith :

It is quite typical for the drop off after the peak on a slip angle vs lateral force curve to be very small.

There are two other points to consider though:
1) Increased tyre scrub will sap forward momentum
2) The lateral tyre force vector points more rearward the further you turn, meaning less of the lateral force is causing you to turn, and more of it is slowing you down

The reason I am learning about this, is because I want to understand what these 'aliens' or whatever you wanna call them are exactly doing for these lap times. When you look at a pretty good lap time, and you look at a WR or near-WR you will see a distinct difference in most corners. The WR-drivers are sliding through almost every single corner, and I really need to know what is going on

They seem to attain more cornering force than you would otherwise have by what looks like oversteer to me.
Is this just a quirk in LFS physics, or is there some reality to this? I have never seen it in real racing, and the closest you get in gokarts is trailbraking which produces an effect like this, but it does not seem like trailbraking is very well liked amongst fast drivers? At least that's what they say! Most of them do trailbrake a bit, but nothing like what you might see in karting where you brake all the way into the apex.