[Bakeme521]

I am looking at putting a ground control coilover system on my car in the next couple months and I am wondering if anyone on here has it and what their experiences with it are?

I run ground control race set up on my track car and it is a great reliable solid system. I don't feel the need for all this adjustable shock dampening on the street b/c it doesn't seem all that useful for just spirited driving. And on top of that those kits are under 1k and the quality doesn't seem all that great in pictures. The basic kit for my car runs about 1700 which seems like a great deal bc the kit for my e36 was 2500, which leads me to another question. On the track car I am running some pretty stiff spring setups so I am wondering what are you guys running on a street setup. A lot of the kits you see people buy on here just come with a set of springs but ground control lets you choose your spring rates and I am not sure what to run on the street with this weight of car.

Any help is appreciated.

[Bakeme521]

Anyone at all? Even if you aren't running ground control can you share what your spring rates are?

[ODUB]

well...way back in the day I had ground control coilovers with tokico illumina shocks (stock shocks couldn't handle it), and I loved them. No idea what the rates were.

On my EVO I ran buddy club racing spec coilovers with 10k/10k rates for well over 160,000 miles and loved them. I swapped to Fortune Auto 500 coilovers with 10k/12k rates and for the short time I rode on them before selling the car, they were great.

the rates I had weren't too stiff for the street, and they did great on the track...but I don't know how you BMW guys rate stiff lol to me it wasn't bad, but I've heard some people bitch at anything over a 6k rate on the street lol

[cstmx_ryder]

I'm on ZSP right now, also thinking about upgrading my suspension. I was thinking about going with the Koni Yellow with Swift Spring conversion coilovers. I was suggested the spring rate of 336/672. But this is mostly for the street and some spirited driving, maybe a couple few times on the track. Definitely NOT a dedicated track setup.

But I agree with ODUB, everyone's definition of stiff is different. So I'm not sure there's a universal answer to your question.........

[mike-y]

Every car's suspension geometry is different, so you can't compare spring rates on an EVO with those on a BMW. you need to calculate wheel rates, and take into account the vehicle weight as well.

For reference, stock ZSP spring rates are 145 lb/in up front, 460 lb/in rear. So keep that in mind when you start choosing spring rates.

Also dampers can affect how a spring behaves, but most street dampers aren't going to be affect it that much. I would give GC a call and see what they recommend. They are usually pretty helpful, and should be able to suggest a spring rate that caters toward your needs, weather it be more for street and comfort, or more of a track setup.

BTW, my track car also uses a GC setup that I've been pretty happy with. And I've changed spring rates a few times over the years without issue.

[Bakeme521]

Originally Posted by mike-y

Every car's suspension geometry is different, so you can't compare spring rates on an EVO with those on a BMW. you need to calculate wheel rates, and take into account the vehicle weight as well.

For reference, stock ZSP spring rates are 145 lb/in up front, 460 lb/in rear. So keep that in mind when you start choosing spring rates.

Also dampers can affect how a spring behaves, but most street dampers aren't going to be affect it that much. I would give GC a call and see what they recommend. They are usually pretty helpful, and should be able to suggest a spring rate that caters toward your needs, weather it be more for street and comfort, or more of a track setup.

BTW, my track car also uses a GC setup that I've been pretty happy with. And I've changed spring rates a few times over the years without issue.

Thanks a lot for the info, I will for sure be giving them a call when the time comes to purchase.

[335isGuy]

Well im looking into the GC kit with the M3 trailing arms. Im looking for 650F 750R but I track my car often when my track car is out of commission.

[Gen_E92]

Originally Posted by 335isGuy

Well im looking into the GC kit with the M3 trailing arms. Im looking for 650F 750R but I track my car often when my track car is out of commission.

I went with 375F 750F for this kit, the ride is still pretty acceptable for DD, but I wouldn't want anything higher either because I don't track my car much. You will also want the M3 subframe bushings for this kind of spring rate.

375# front springs are special GC spec because the softest 6" spring that Eibach makes is 450#, you can probably still get away with that for DD with 800# or 850# rear springs.

BTW $2100 for this kit is just awesome if you look at how much the M3 lower camber links (not trailing arms) are going for now, the kit even comes with camber plates.

[lpphreakx06]

I went with 375 and 630 with swift springs. I'll let you know how it is when i install it.

[Projekt_BooGie]

reviving this thread so I don't have to make another one. I was what spring rate did you decide on? I'm thinking about going BC b/c I can choose spring rates

[E90335iflyer]

sorry to bring this back again, but can't find too many GC koni coil over reviews, anyone?

[DallasBoosted]

Originally Posted by E90335iflyer

sorry to bring this back again, but can't find too many GC koni coil over reviews, anyone?

I ordered the full GC SA kit with rear M3 trailing arms, camber plates and the GC rear toe links last week. I got 525f/650r rates.

I will let you know my thoughts once I get it installed.

[cvc 22349a]

Originally Posted by DallasBoosted

I ordered the full GC SA kit with rear M3 trailing arms, camber plates and the GC rear toe links last week. I got 525f/650r rates.

I will let you know my thoughts once I get it installed.

Wow. I've never heard of anyone using that high of a spring rate up front on an E9x. Is it primarily a track car? Does GC have Koni revalve the struts?

[tres]

im running 450 f 840 r and it feels softer than stock with rft i guess its because the dampers are tuned to the springs. but I'm going back to stock rates for winter

[DallasBoosted]

Originally Posted by cvc 22349a

Wow. I've never heard of anyone using that high of a spring rate up front on an E9x. Is it primarily a track car? Does GC have Koni revalve the struts?

Its kinda my daily driver, but I work at home so I don't really go anywhere. I have a Lexus LS460 for the family hauler.

Yes GC has custom valving on all of their struts matched to the spring rate you choose. Thats why they don't have kits "in stock" they build it after you decide what you want.