[Wally]

This formula can help you work out if your car is understeery or oversteery.

Here's a trace in a car set up to be deliberately understeery. Where the graph is > 0 (which corresponds to corners), the car is understeering.




Here's a trace in a car set up to be deliberately oversteery. Where the graph is < 0 (which corresponds to corners), the car is oversteering.




This is my own race setup hotlap. On balance, a little understeery. I could do with a little more front wing.



In Race Studio, the formula is:

IF(GT(G_LAT,0.1),STEERANGLE*DEG2RAD/(-G_LAT*ACCGRAV)-(WHEELBASE/((SPEED*KMH2MS)^2)),0)

You have to edit the predefined WHEELBASE constant to be the wheelbase of your car (2.65m for the Formula Abarth).

You can create your own math channel for this which gets inserted as a channel into each test you open. Ask me how if you want to know.

[Rolz]

ouch... instant headache 

though it looks neat...

me drive car *grunt*

[Wally]

I've always been looking for something in the telemetry that actually shows me what I should do to the car setup. These graphs clearly tell me that I am understeering in the corners, even though it doesn't really feel too bad. The proof of the pudding is always what it does to your lap times though.

[Guybrush Threepwood]

IMO you always want a little understeer so you know you are getting full traction from the rears and maximum cornering lock.  I'm guessing the big understeer moments following the oversteer in the graph is the correction?

[Wally]

IMO you always want a little understeer so you know you are getting full traction from the rears and maximum cornering lock.  I'm guessing the big understeer moments following the oversteer in the graph is the correction?

Yeah, they were full on, spin inducing oversteers (took all the rear wing off... fun!)

[Gratulin]

Does the tire squeals in AC tell you that there is understeer/oversteer? Since I setup some rear speakers I can tell exactly which tire is protesting. I currently use it for feedback on how hard I can push.

[Bacchulum]

Where the heck are you doing all this?
Where's the 'predefined wheelbase'?

[Wally]

Where the heck are you doing all this?
Where's the 'predefined wheelbase'?

Find the math channels. You can create a general math channel and say insert this into every file you open. There's also a constants section, where a WHEELBASE is defined. You can then change its value. I'll post some screen shots later.

[Wally]

Where the heck are you doing all this?
Where's the 'predefined wheelbase'?

Here you go. Go to Math Channels (Alt-F8):

[Wally]

Does the tire squeals in AC tell you that there is understeer/oversteer? Since I setup some rear speakers I can tell exactly which tire is protesting. I currently use it for feedback on how hard I can push.

Couldn't say - I only have stereo. But it's gotta be valuable feedback.

[Bacchulum]

Thanks Wally.

All that for a straight line.
(just means my setups good )

[Wally]

Thanks Wally.

All that for a straight line.
(just means my setups good )

Did you set the min and max scale of the Kus graph to about +0.5 and -0.5? You can right-click on the Kus measure and set the min & max in the window that pops up.

[Guybrush Threepwood]

Thought you might be interested in this Wally:

http://www.f1fanatic.co.uk/2014/08/07/ferraris-telemetry-lap-hungaroring/

[Wally]

Man, that's telemetry pr0n. Look at those sexy brake traces... extremely hard on the brakes and then smoothly but rapidly released. So consistent.

[Bacchulum]

Where did you find the maths channel formula Wally?
Were there any others?
I might have to go through my collection of Racecar Engineering, Data Bytes column and see what's in there.