Rear Coil Spring ½ inch Drop GTO, Grand Prix, Lemans, and Tempest 1967-1972 #S-61

Global West Suspension sells 1/2 inch drop rear coil springs for the GTO, Grand Prix, Lemans, and Tempest--(model years--1967, 1968, 1969, 1970, 1971, 1972).

Recommendations:

Global West highly recommends linear rate springs (also known as constant rate) over variable. Although variable rate springs are not bad, installing linear rate springs provide the best performance for our customers.

Here are reasons why we prefer linear rate versus variable:

Consistency: As a linear rate spring is compressed, the resistance increases per inch equal to that of the rate. For example, if a spring is rated at 300 pounds per inch, for every inch of travel the spring compresses, the resistance increases 300 pounds. Therefore, one-inch of compression will provide 300 pounds of resistance, two-inches 600 pounds, and three-inch 900 pounds. For drivers who are looking to improve skills, vehicles must give predictable feedback each time during cornering and trail braking. A linear spring will do that because the rate is consistent.

What happens when you install variable rate springs:

Variable rate springs, however, do not increase in the same fashion. They are generally rated with a lower spring rate on initial and build to the desired rate. For instance, the first one-inch of travel might start out as 250 pounds per inch, the second-inch 560, and the third 900. For a driver who is looking to improve their driving skills, a vehicle must give predictable feedback each time during cornering and trail braking. A linear spring will do that because the rate is consistent.

Less chance of bottoming:

Lowered cars always have reduced suspension travel. The lower you go, the less travel is available. Variable rate springs tend to allow more travel before the spring can build rate, keeping the suspension from bottoming. The question is: Is there enough suspension travel available while the spring builds enough resistance (rate) before bottoming occurs? Variable rate springs tend to overemphasize the geometry curve, giving us more tire movement than necessary.

Why do we lower springs:

These springs from Global West generally lower the vehicle one-inch in the front and up to 1-1/4 inches in the rear depending on the option for your vehicle.

Why we only lower about one-inch in the front?

There is not enough suspension travel beyond one-inch for street applications. We admit, vehicles lowered one-inch look great, but they generally run into suspension bottoming problems. Header to ground clearances tend to be another issue. Therefore, in our experience, we believe one-inch makes the most sense especially if the car is driven on the street.