This unit uses no coil springs; it is all hydraulic. Typical spring links travel less as traction deteriorates during the race. That is because coil springs have progressive resistance. The Trax Link requires a constant amount of pressure to compress it through its entire range of travel. The TL500 has 1/2" of total travel allowing you to set the right side wheelbase long for increased turning without losing traction or set it square or even ahead for maximum bite.