Ground Control Coilover Problem

[Deadspool]

Originally Posted by Kodi

I would take them off, but I already invested 250.00 in corner balancing. I'm gonna leave them till I get some real coil overs. I was going to get Koni yellows, but GC said these sleeves don't work with Konis. Those sleeves are an additional 44.00 per end.

That sucks.

I had good luck with GC's on my DSM's

[fooddude]

Was really close to GCs. Guess I will look for another option.

[YodrOne]

Deadspool/Kodi,

So what's the verdict on this GC kit? I was about to pull the trigger until I came across this thread. The rates are much firmer than your standard HK sport springs which I like. I don't care much about lowering the car, I just want to eliminate some roll primarily for track/autocross use.

How much does the 6"/6" or 6"/7" spring actually lower the vehicle?

Do you feel the the stock damper is able to deal with the additional stiffness? We're talking about a 300% increase. How does it feel over rough roads, general street driving? Not too bouncy?

Any issues with installation/fitment other than what was described? I'm gonna be doing it myself.

Any input much appreciated.

[Deadspool]

Here is what ive come to.

For a modest lower, about 1.5'', GC's actually feel great. The product is well done, but it seems as we are limited by out factory spring perches. They are not as low as the sportlines, but they do feel A lot nicer. Smooth and firm.

The ride was firm enough to actually inspire confidence over my Sportlines. It was not so firm as to feel any level of harshness, it just felt planted. With the sportlines I found the ride to be overly bouncy. the GC kit was smooth.

I bought these with the intention of closing the rest of my wheel gap, this kit cannot provide that, therefore on a personal level, they are not what i am looking for.

The stock damper will be fine with this kit, I can see much less stress on them from this kit over the sportlines.

I did the install myself, In the link I posted there are a few pictures during the process, it is very straight forward. I can offer one HUGE piece of advice though. Do not allow the shaft in the stock damper to spin, If it spins the internals risk coming apart and they will blow. I've destroyed one complete set, all four, by doing it the old fashioned way with an impact gun on the hat.

This is a good kit, its just not the kit for anyone looking to slam by by any means. I find it to be very much performance oriented over style.


If I cant return my kit, I will be selling mine in favor of BC's.

[YodrOne]

Originally Posted by Deadspool

Here is what ive come to.

For a modest lower, about 1.5'', GC's actually feel great. The product is well done, but it seems as we are limited by out factory spring perches. They are not as low as the sportlines, but they do feel A lot nicer. Smooth and firm.

The ride was firm enough to actually inspire confidence over my Sportlines. It was not so firm as to feel any level of harshness, it just felt planted. With the sportlines I found the ride to be overly bouncy. the GC kit was smooth.

I bought these with the intention of closing the rest of my wheel gap, this kit cannot provide that, therefore on a personal level, they are not what i am looking for.

The stock damper will be fine with this kit, I can see much less stress on them from this kit over the sportlines.

I did the install myself, In the link I posted there are a few pictures during the process, it is very straight forward. I can offer one HUGE piece of advice though. Do not allow the shaft in the stock damper to spin, If it spins the internals risk coming apart and they will blow. I've destroyed one complete set, all four, by doing it the old fashioned way with an impact gun on the hat.

This is a good kit, its just not the kit for anyone looking to slam by by any means. I find it to be very much performance oriented over style.


If I cant return my kit, I will be selling mine in favor of BC's.

Thanks for the additional insight. This definitely sounds like the kit for me. I really don't have any interest in lowering the car much; 1" would be more than enough. I rub in certain parking lot entryways as is, and barely make it into car washes.

I know GC to be a quality product from my e46 experience so was a bit concerned about some of the issues you guys were having, but again ride hight is not a priority for me.

If you're definitely selling your kit please PM me. I have a lot of track time starting in the next four weeks and will hold off on ordering a new one if we can come to an arrangement.

[Deadspool]

I'll let you know what comes of it in the next few days. See what hoops the seller will have me jump through.

Returning them would work in my favor, as I paid $419 + $79 shipping +$81$ taxes converted into american.

[Racecomp Engineering]

IMO going past 5 kg/mm (280 lbs/in) spring rates on stock shocks is exceeding what they can handle. Our tarmac lowering springs are about that and we only recommend using them with konis or bilsteins.

We (and othes) posted shock dynos of the OEM stuff and those rates might not feel completely horrible but the oem dampers are much too soft to control them for performance driving.

- Andy

[Deadspool]

You guys defiantly have the gear to test such things.

[Kodi]

Originally Posted by YodrOne

Deadspool/Kodi,

So what's the verdict on this GC kit? I was about to pull the trigger until I came across this thread. The rates are much firmer than your standard HK sport springs which I like. I don't care much about lowering the car, I just want to eliminate some roll primarily for track/autocross use.

How much does the 6"/6" or 6"/7" spring actually lower the vehicle?

Do you feel the the stock damper is able to deal with the additional stiffness? We're talking about a 300% increase. How does it feel over rough roads, general street driving? Not too bouncy?

Any issues with installation/fitment other than what was described? I'm gonna be doing it myself.

Any input much appreciated.

I too bought this kit for autocross. I wasn't looking for lowering so much as for improved handling and adjustability. We were unable to achieve more than a 3/8 inch drop because of the limitation of the rear sleeves. Overall, extremely disappointing. The ride is not bouncy at all, and the rear hooks up better and is more controllable. The car looks ridiculous and rattles over sharp bumps. I will be looking into "real" coil overs soon. The Koni yellow route would be pretty expensive and still leave me with having to purchase 90 bucks worth of sleeves.

[YodrOne]

Originally Posted by Racecomp Engineering

IMO going past 5 kg/mm (280 lbs/in) spring rates on stock shocks is exceeding what they can handle. Our tarmac lowering springs are about that and we only recommend using them with konis or bilsteins.

We (and othes) posted shock dynos of the OEM stuff and those rates might not feel completely horrible but the oem dampers are much too soft to control them for performance driving.

- Andy

Thanks for chiming in Andy. I don't want to clutter this thread or any other for that matter, but I just posted in a Swift discussion thread below, getting more specifically to what you're talking about with regards to what the stock dampers could actually handle before you start seeing degradation in track performance.

I'm new here so this might have been discussed in other threads (I haven't searched in the DE/track section yet), but if you can expand a bit more on what you've seen in testing the stock damper and what the maximum recommended spring is, that would be much appreciated. A reference to a previous thread is great...

I'm big on vendor reputation from personal experience and GC is a solid company with a strong pedigree. It's puzzling why they would go with a spring that would completely overpower the stock damper and undermine track performance.

I just posted here:
http://www.ft86club.com/forums/showt...t=44935&page=2

[fooddude]

If anyone is running these sleeves successfully (ie: lower than .5-1" and without any "too high" problems), please post on this thread. Pictures would be great.

And, if any of you guys found a solution/fix (maybe from GC with the shorter 6" springs), please post.

Btw, is it only the rear that can't get lower than .5-1"?? Can the front go lower and does the front have more adjustability? Or is it all 4 corners?


I bet f5"/r6" springs will give a much better lower, than the included f6"/r7" springs (which seem to not even lower much even at max lowest adjustment).

Just seems very odd, that GC included wack spring lengths in this sleeve kit, that need to be maxed-out to even give a small lower... it's like not even having a "height adjustable coilover-sleeve" anymore if you think about it, especially since any other setting than maximum lowest setting will result in a stock ride height, if not higher than stock, lololol. If you're reading this, get your act/r&d together GC! Seems like they didn't even do any tests/fitments/r&d at all on this sleeve kit on an actual car, and instead just slapped together this sleeve kit from a few measurements :/ ..I'm sure they did testings/r&d for their more expensive coilover-koni combo kit (from past threads).. but what about the cheaper ala carte spring sleeve kits??

[Kodi]

Originally Posted by fooddude

If anyone is running these sleeves successfully (ie: lower than .5-1" and without any "too high" problems), please post on this thread. Pictures would be great.

And, if any of you guys found a solution/fix (maybe from GC with the shorter 6" springs), please post.

Btw, is it only the rear that can't get lower than .5-1"?? Can the front go lower and does the front have more adjustability? Or is it all 4 corners?


I bet f5"/r6" springs will give a much better lower, than the included f6"/r7" springs (which seem to not even lower much even at max lowest adjustment).

Just seems very odd, that GC included wack spring lengths in this sleeve kit, that need to be maxed-out to even give a small lower... it's like not even having a "height adjustable coilover-sleeve" anymore if you think about it, especially since any other setting than maximum lowest setting will result in a stock ride height, if not higher than stock, lololol. If you're reading this, get your act/r&d together GC! Seems like they didn't even do any tests/fitments/r&d at all on this sleeve kit on an actual car, and instead just slapped together this sleeve kit from a few measurements :/ ..I'm sure they did testings/r&d for their more expensive coilover-koni combo kit (from past threads).. but what about the cheaper ala carte spring sleeve kits??

It is only the rear that presents a problem. Front has plenty of adjustment. GC sent me 6" springs for the rear, but it seems that they may be too stiff at 400#. I am going to see if they will exchange them for 375#. I dont think shorte springs are a good answer as the stock shocks have limited travel and 5 " may leave you sitting on the bump stops under compression.

[Luis_GT]

A bit late, but I was having the same issue with my kit, I was looking for a square 1" drop and only managed about 7/8" front and 1/2" rear. GC sent me a new set of springs to test out, 5" front and 6" rear. vs 6" front and 7" rear.

The downside to this is stiffer spring rates, I may have to order new shocks, as it felt very pogo-ish over large bumps with the 375lb f and 425 r, but surprisingly it felt stock over cracks and badly filled pot holes.

New setup is 425lb f and 440lb rear... Will report back when I install them... but I think I may end up selling my kit as well unless I can get the it to be more OEM like with a new set of shocks. I think my car went airborne over a hump in a badly made bridge joint... not fun... especially when it also caused me to fly off my seat... Thank god for seat belts...

[fooddude]

Originally Posted by Luis_GT

A bit late, but I was having the same issue with my kit, I was looking for a square 1" drop and only managed about 7/8" front and 1/2" rear. GC sent me a new set of springs to test out, 5" front and 6" rear. vs 6" front and 7" rear.

The downside to this is stiffer spring rates, I may have to order new shocks, as it felt very pogo-ish over large bumps with the 375lb f and 425 r, but surprisingly it felt stock over cracks and badly filled pot holes.

New setup is 425lb f and 440lb rear... Will report back when I install them... but I think I may end up selling my kit as well unless I can get the it to be more OEM like with a new set of shocks. I think my car went airborne over a hump in a badly made bridge joint... not fun... especially when it also caused me to fly off my seat... Thank god for seat belts...

Please post pics and a review when you get the new springs installed ...I'd love to hear the adjustment range with the new lengths.

Wow that's stiff...but attracts me for track/performance use. Konis or Bilsteins are calling