Carlos01SS

iTrader: (4)

GC(read Ground Control) coilovers use Eibach Racing Springs for the fronts, much narrower than what you think of regular front springs for our cars, see pic.



The ERS front springs are linear, these are 500# fronts...The Koni DA springs shown needed to have the upper "hat" grounded down in order for the ERS front springs to fit over the shock--Sometimes folks can loosen the bolt that holds the upper damping adjusting hat, but Guldstrand Motorsports in Burbank spent 2 hours trying to loosen it to no avail, hence the necessary grounding of the front shocks...
Notice how the red springs are sitting on a brass lip that you unscrew to raise where the shocks rest, this is how you raise/lower your car. Every time you adjust ride height in the front, know that you'll have to get a front alignment, so keep that in mind...

The rear ERS springs are basically the Eibach Prokit springs, progressive @150#, they set like regular atermarket springs, but notice the brass lip that sits on the threaded red aluminum sleeve, that's how you adjust the rear...



If you order the GC Coilover setup, the rear springs will not be powdercoated, I had the fronts & rear done at the same time so they're the same color...Most people wouldn't worry about it, but I did.

The factory ride height(well, MY factory ride height) is about 27-3/4" front & 27-1/2 rear, when Guldstrand did it initially it was 24-1/2" and it was WAY too low, I was scraping into everything, BAD CALL.

Now fronts are 26" even & 26-3/8" rears, and it's still a bit low...

Be careful what you ask for. Too low will be a horrible ride.

trackbird

iTrader: (4)

Carlos, that's excellent information and the pics really help (for those who haven't seen the GC stuff).

Carlos01SS

iTrader: (4)

Thank you sir, I try to help.

Foxxtron

iTrader: (1)

I also agree with trackbird's and Carlos01SS's findings with the above request. Not only will lowering with most of the replacement shocks leave you with less room for shock travel, but also with suspension geometry and Cg problems as well. These are problems even before the wheels will make significant contact with the inner wheel well. 1.5" less than OE Z28 ride hieght is quite low enough already.

These demands are nothing new in the department of wanting to turn the vehicle into something that's not just possible with a majority of the available aftermarket equipment.