First off, to avoid a flamewar, this is not for racing or drifting. It's just a tech idea.

Does a car gyro exist where the gain can be configured proportionally to the throttle channel ?

So for example have no gyro effect < 50% throttle, and linearly interpolate from 0% gain at 50% throttle to max-gain(f.e. 60%) at full throttle.
This way the gyro would only be used on high speed and/or power bursts, and it would still be possible to throw the car around a corner off-throttle.