GC's are good but real coilovers are more expensive for a reason. the strut is built for the stiffer spring rate and is often shortened, lowering the car via the shorter strut, not harder, shorter springs. You can still drop a car on real coilovers by raising or lowering the perch like on gc's. the problem with raising or lowering the perch is that it effectively changes the spring rate by compressing or decompressing the spring. A friend of mine hade GC's and then got Tien HA's and said the difference was night and day. the other advantage of real coilovers is that the springs are often much longer than GC's thus providing a better ride quality too.
Here is the bottom line, save a bit more money and get a better setup that handles and feels better than GC's.
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