I have been reading the Speed Secrets by Ross Bentley and learned about Slip Angle. I had never heard of it before, which tells that I'm pretty new to racing. I've been turning the PC wheel controller for about 6 years now, but only about 1,5 years ago I started with simulations GTR and now with LFS. So I downloaded the F1PerfView and saw that I'm mostly having slip angles from 0% to 3% with MRT in Fern Bay Gold. According to what Bentley writes I'm not using my tires and I am slow. OK, accepting that, I downloaded one WR lap and opended it, and saw only slightly bigger slip angles. So what should I think now? Was the WR not so good after all? Or is the slip angle statistics not so accurate with LFS/F1PerfView?

Quote from romus74 :

I have been reading the Speed Secrets by Ross Bentley and learned about Slip Angle. I had never heard of it before, which tells that I'm pretty new to racing. I've been turning the PC wheel controller for about 6 years now, but only about 1,5 years ago I started with simulations GTR and now with LFS. So I downloaded the F1PerfView and saw that I'm mostly having slip angles from 0% to 3% with MRT in Fern Bay Gold. According to what Bentley writes I'm not using my tires and I am slow. OK, accepting that, I downloaded one WR lap and opended it, and saw only slightly bigger slip angles. So what should I think now? Was the WR not so good after all? Or is the slip angle statistics not so accurate with LFS/F1PerfView?

Slip angles on the MRT are a bit unusual because of the tiny little wheels i.e. small sidewall, and the fact that the fast sets for it run with high tyre pressure. High pressure = smaller slip angles.

Try some other cars and you may find the opposite.

Look at RB4 rallycross and see what slip angles you get then.

Admittedly dirt is different to a hard surface though.

I'm not entirely sure, but I think the slip angle in f1perfview is for the front wheels, not the rear wheels.

Try making a set that understeers massively and move the wheel a lot. Then check the slip angle.

If the slip angle in F1PerfView really means what is described here http://en.lfsmanual.net/wiki/Telemetry#Data_Items then I'm affraid it's not correct.

Quote :

Slip Angle. Difference between steering radius and actual radius, measured in steering degrees. Negative indicates understeer, positive indicates oversteer.

This paper http://www.engr.colostate.edu/ ... ing%20Tire%20Modeling.pdf has a nice figure showing the correct definition of slip angle.

As I said, I'm pretty sure the Slip Angle given is for the front wheels. If you want to find the slip angle for the rear wheels, use this formula:

|Steering Angle| + front "Slip Angle" = rear slip angle

I just exported the data to an Excel spreadsheet and the data that results from this calculation seems to make sense. During my WR run at WE1R in the FO8, my rear slip angle peaked at just under 4 degrees while exiting the first decreasing radius hairpin. Under normal high speed conditions, it didn't go over 2 degrees.

OK, thanks for the answers. Currently I'm pretty obsessed with the MRT, feels like I could drive this season with it, so I'll skip testing other cars for now.

But, as long as I get my tire temperatures to green area I guess I'm driving hard enough, no matter what the slip angle is accoding to stats.

You might want to compare F1PerfView output with this. The attachment shows the slip angles (vertical axis) from the WR lap in MRT at Fern Bay Gold calculated with RAFTyreExtract (the version used is not entirely ready yet). Front left wheel is in red, front right in green, rear left in blue and rear right in black. Understeer is defined as front slip angles being larger than rear slip angles and you can see it happening in many corners during the lap.