I am running dual steering springs on my fast car.
I simply added a second spring, nothing more to it than that.

The whole idea is to mellow out that tight, twitchy steering when your car has been speed modded.
Of course it's gonna spin or flip otherwise, these things have like no wheel base!

Not to mention the fact that it's just not going to turn that sharp at high speeds. (It's called Physics)

Yes, the turning radius is opened up a little by doing this, but not by twice as much, and the gain is a fast car that stays controllable, so you don't have to be "Johnny thumb flip" to keep your car going where you want it to. It also helps to have more centering return at higher speeds.

The "weaker" force you exert on a full size car's steering means IT doesn't flip or spin at high speed either.