Hi there, the droop limiters are fitted to my car.
The reason been as you know the car squates at the back under acceleration so you fit stiff springs (600lbs) to stop the rear end squat. But this now means that the car lifts at the front so the weight is again transfered to the back.
The droop limiters prevent this by ristricting the front suspension droop.
The side effect of the limiters are that cornering hard on a track it can prevents the front inside wheel maintaining contact with the track so looses traction/drive. But this is dependant on spring rate!
I worked/built on a Pilbeam MP/84 LM2 sportscar that raced at Le Mans that had a simular device fitted.
Simon.