Skidmarcx

I have the GC setup with the 500/550 springs. I also have a mixed shock arrangement with FE4 up front and FG2 in back because of a bad front shock and no single FG2 available at the time. To the previous owner it was probably fine, but for me it just seems too soft, sloppy, and too much body roll. The dampening feels even to me, but I know it's still kind of odd to have the different shocks. While there are many options as far as different springs, shocks, sway bars, etc.. I'm unsure which to tackle first. From what ive read the hotchkis kit is worth getting, but that only solves body roll. I was looking at maybe going with a 600/650 setup, but I'm wondering if it will affect weight distribution and traction under heavy acceleration... Anyways I read through some previous threads, but couldn't find specific feedback. I don't track the car... It's my DD and will occasionally run the 1/4. Any help is appreciated

branland

iTrader: (2)

I have the GC too and just went back to the 600 \ 650 springs. I had the 500 \ 550 springs thinking it would make the car ride better but all I got was a sloppy ride. Rolling into the throttle coming out of the turns would make the back of the twitch instead of rotate.
I put the stiffer springs back in and raised the car about 1/2 and if feels fine now. It looked better slammed, but what I have now is a good compromise.

NeverSatisfied02

iTrader: (12)

Can't u turn the height down with the GC kit (perches) to compensate for the stiffer springs making it sit slightly higher?

Skidmarcx

Thanks I'm leaning towards the stiffer springs, but I wanted to hear opinions. My buddy was saying I shouldn't because of weight transfer when launching during a race, but I also have roughly 200lbs of extra weight from audio equipment and dynamat which will help me with traction. Do you happen to have part numbers? Or should I just call GC directly?

The rear dictates how low you can go since its not a strut or coilover setup

NeverSatisfied02

iTrader: (12)

So you're saying the rear isn't really adjustable. Only the front? Cause I've seen some cars sitting slammed with GC kits. Ferny's car is low but I recall him saying he had to remove a perch or something to make it that low.

CTSV_510

iTrader: (1)

The rear comes down 1" with ground control, no lower unless you start modifying the mount even more than the instructions call for, with something like the mighty mouse kit. You can't really raise the height in the rear due to the short length of the springs, but a 1" drop will have no ill effect on anything so I can't imagine you would want it raise it back up.

I had no weight transfer issues at the drag strip with my 600/650 springs, the car hooked very well. I think the 600/650 rates are perfect and I wouldn't have wanted to go lower, but I don't drive it more than 3 to 4 days a week and it's not on bad roads when I do.

NeverSatisfied02

iTrader: (12)

Damn... So the H&R's prob drop the car lower in the rear than the GC kit

Skidmarcx

The rear has very limited adjustability... I took the adjuster ring out to drop it another 1/2". Mine sits pretty nice, but not as low as an H&R spring

Nice to hear thanks

Pretty much

NeverSatisfied02

iTrader: (12)

If that's the case, I think I'll stick with my H&R and just get some K-Sports later if needed. I was under the impression the GC kit would go much lower than that.

Skidmarcx

Yea I think it's more for picking your spring rates and adjustability rather than going slammed. It was on the car when I bought it, so I figure I'll get it to where I like it

NeverSatisfied02

iTrader: (12)

That's true. A big advantage there in itself. I just like the slammed look and since it's my daily and I'm not tracking it, spring rate choice would be nice but not 100% needed in my case.

Btw, what wheels are u running? They look like polished accessory wheels in ur avatar but bigger. Lol

Skidmarcx

Indeed they are the polished accessory wheels

NeverSatisfied02

iTrader: (12)

They look nice on there man. Knew that had to be what they were unless u had some CCW's or something.

Appreciate the heads up on the rear spring lowering amount with the GC kit. Would have been pissed if I sold my H&R's and ordered those to find out they won't even get as low as the springs alone. Lol

Cadzilla

iTrader: (3)

The stock shock's pressurized design is what limits the drop in the rear with the gc kit.. With qa1s you can slam it. The fe4 and fg2 reach a rested compression limit whereas the qa1 does not.

The fg2 will allow even less drop than a fe4 because it's much tighter. The mm kit ultimately raises the mount point of the shock allowing for even more drop with the gc kit and stock shocks, and is a much better option than removing the upper perch. I wouldn't remove that... although it seems in place I can't see what would hold the spring in place in the event the suspension was unexpectedly unloaded..

FuzzyLog1c

iTrader: (4)

All of you guys need to do more research before you start dismissing Ground Control. Their basic kit for the CTS-V includes 10" long springs. The reason why you can't drop the back end way down is because those default springs are too long. Solution: call GC and tell them you want a set of Eibach 800.250.600 springs for the front and 800.250.650 springs for the rear. Then go on eBay and spend the $120 for a set of four C5/C6 endlinks. Finish it up with a trip to Home Depot for four 12mm washers four 12mm nuts, and a drill bit to ream out the existing holes.

Oh, and by the way, if you're concerned with body lean, start with the Hotchkis sway bar kit. Don't bother with springs. Sway bars are the only way to reduce body lean. You could replace your springs with solid steel plates and it wouldn't help your lean issues a bit. Keep in mind that a stiffer sway bar will also make your car's response to common mode transients (i.e.: bumps you hit with both wheels at the same time) much faster and harsher.

Regardless of what you decide to do, I don't want to see this:

NeverSatisfied02

iTrader: (12)

Sweet! Makes sense! I wouldnt want to remove perches or ruin the integrity of the kit. But... The custom ordered shorter springs seems like a great idea. And the MM kit would be used regardless to avoid any self leveling.

NeverSatisfied02

iTrader: (12)

Only question is... Would it be worth it to do all of that or just order some K-Sports for a little more which would be fully adjustable and come with new shocks.

FuzzyLog1c

iTrader: (4)

I have the MM kit. I installed it, test drove with it, and subsequently removed it.

It's presently sitting in a box, collecting dust because it's absolutely unnecessary.


K-sports are unreliable, cost more than double what you'd be spending (you'd still have to buy end links), and are incompatible with aftermarket rear sway bars.

Cadzilla

iTrader: (3)

Why would you go with an 8" 650 in front vs the std 10" in 650? There's no limit to drop in the front.

you can slam the rear with qa1 even with a 10" spring

NeverSatisfied02

iTrader: (12)

And u don't have any self leveling issues with the stock shocks? Cause my old car would self level until I put some spacers in the rear.