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Koni/Ground Control users, need your input! Issue with my setup.

Joined
20 October 2015
Messages
145
I posted my issue on the nsxprime Facebook page, but maybe I'll get a better response here for what I need.

I recently received and installed the Koni/GC coilover setup, ordered direct from GC and came assembled and ready to install. I ordered spring rates of 650#/550#, all in 6" free length springs. After installing, I dropped the car and quickly noticed the car was still at around the stock height. Raised the car up, lowered the front coilovers to their lowest possible setting and the rear just a bit. Dropped the car and noticed very little change. The car dropped MAYBE 1/2" from stock suspension height all around. BUT, looking at the suspension, the front coilovers are literally resting on the bump stops. They are sitting on the bump stops, with no more room to lower, ZERO suspension travel allowed and the car still looks like it's at stock height.

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The rear is a little better, but not by much. As the car sits, I have about 1" of travel before hitting the bump stops. BUT, the car is still at around stock height. If I lower the car any more, which I would want to, then the rear will now be resting on the bump stops. No travel, still not very low.

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I've contacted Ground Control. Sent them pictures. Explained everything. The person I spoke to said the part numbers are correct, everything looks installed correctly. His suggestion was to put the SOFTER springs up front and to cut the bump stops. He thinks this could solve the travel issue and lower the car. Putting softer springs up front will not solve anything. Cutting the bump stops still will not solve anything either, because ideally I would still want to lower the car at least an inch. If I cut the bump stop and lower the car, I'll still be left with VERY little shock travel or be resting on the bump stops again.

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I show this all to my friends. All of which have countless of years dealing with aftermarket suspension, racing, some are automotive engineers who design aftermarket parts. We all come to the same conclusion. Something is not right in the design of this coilover as it is. I am waiting to get a call back from the Ground Control owner or whoever is in charge of designing this setup to get their input. Their website has listed that this suspension should get me 0"-3" of drop, that is CLEARLY not the case. Even if I were to remove the bump stops entirely, I don't think I'd get closer to a usable 3" drop.

In the meantime, if anyone here has or has used the Koni/GC setup, I would really appreciate you posting photos of your coilovers and your cars ride height. I'll even appreciate posts of other coilover companies to be able to make a better comparison and have a better idea of what something SHOULD look like and how something SHOULD work.
 

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This whole package looks strange to me. NEVER should the spring be loose when the shock is fully expanded. This is seriously dangerous! As well as riding on the bump stops.

I would return this ASAP and want my money back. There are enough good value for money suspension options for the NSX that do not have this issues.

Bernhard
 
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The spring not having preload isn't the biggest deal. Speaking from experience with my 2 other cars I race with the same Koni/GC that don't have preload, it's never been an issue. I don't believe this will ever be an issue on the NSX, the wheels will more than likely always be loaded and not lifting, in turn basically always having preload on the suspension unless the car is jacked up to work on.

Unfortunately I don't believe there are many other coilovers in this price range that match the performance and longevity that Koni and GC can offer. I've had Koni/GC on my other 2 cars for many years, race and abused. Never a single issue. Adjustment in the shocks is good and noticeable. I don't want to shell out $2500+ for a setup that I will not seriously compete on, nor do I want to spend $900 on a setup that is questionable on how long will really last before needing a revalve/rebuild(if even possible). IF these could be made to work properly, I'll stick with it. Just waiting to hear back from someone at GC hopefully on Monday..
 
AJ, if you want to compare my Koni shocks against the ones you got, you are welcome to do so. They are sitting in a box in my garage. -Jason
 
I have Ground Controls with Koni shocks for nearly 10 years. Well, it seems GC still doesn't know a damn thing about NSX fitment.:confused:

I also had issues when installing my new set years ago. It was a different issue where the front was about 1" higher that stock at the lowest height setting due to GC installing the wrong threaded collars. It involved installing/uninstalling a number of times, swapping front/back springs, sending pictures, multiple phone calls to GC and finally shipping them back to GC for shock modification and installing proper length collars. It was a major headache to say the least.

Not sure what's going on with your set. I'm no expert, but from what I can tell everything looks okay except the bump stops do look too long. Unfortunately I don't remember how much travel there is between the shock and top.

The lowering height is definitely not up to 3", more like lowers 1.5"-2"max. From what I remember, my car height setting is close to the bottom of the collar. I don't know exactly where my car's height compares to stock, but I'm guessing it's lowered about 1.25" with something like 0.5" left of thread to adjust lower.

My car is basically in storage now so I can't snap any pics of the suspension. I had some old pics when I initially did the install but I can't seem to find them now. Here's a old pic of my car's ride height as it sits now with 17"/18". Sorry, no direct side view.

Good luck, hope you get it sorted out soon.

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AJ, if you want to compare my Koni shocks against the ones you got, you are welcome to do so. They are sitting in a box in my garage. -Jason

Jason, if you wouldn't mind sending me a picture of it, that might be enough. If you could get a shot of it with a measuring tape from the top of the body(where the shaft comes out) to the bolt hole that would be even better. But don't stress it, not that big of a deal.

It looks as though they didn't machine down the pedestal ridge of where the threaded body meets the shock.

Ref: http://www.nsxprime.com/forum/showthread.php/155166-Koni-with-ground-control-modification

Also, most sales thread of GC's show a substantially smaller bump stop as compared to yours.

http://www.nsxprime.com/forum/showt...nd-Control-Coilovers?highlight=ground+control

http://www.nsxprime.com/forum/showt...l-Coilovers-for-sale?highlight=ground+control

Yeah I've noticed on all the others, they use much shorter bump stops. Not sure why GC sent these. Regardless, I feel that wouldn't entirely solve the travel issue. I'm just thinking about driving around highways and hitting bridge over passes, it seems guaranteed I'll be slamming the bump stops at every minor bump..

I have Ground Controls with Koni shocks for nearly 10 years. Well, it seems GC still doesn't know a damn thing about NSX fitment.:confused:

I also had issues when installing my new set years ago. It was a different issue where the front was about 1" higher that stock at the lowest height setting due to GC installing the wrong threaded collars. It involved installing/uninstalling a number of times, swapping front/back springs, sending pictures, multiple phone calls to GC and finally shipping them back to GC for shock modification and installing proper length collars. It was a major headache to say the least.

Not sure what's going on with your set. I'm no expert, but from what I can tell everything looks okay except the bump stops do look too long. Unfortunately I don't remember how much travel there is between the shock and top.

The lowering height is definitely not up to 3", more like lowers 1.5"-2"max. From what I remember, my car height setting is close to the bottom of the collar. I don't know exactly where my car's height compares to stock, but I'm guessing it's lowered about 1.25" with something like 0.5" left of thread to adjust lower.

My car is basically in storage now so I can't snap any pics of the suspension. I had some old pics when I initially did the install but I can't seem to find them now. Here's a old pic of my car's ride height as it sits now with 17"/18". Sorry, no direct side view.

Good luck, hope you get it sorted out soon.

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^ Thank you for your input! That is helpful to know. Found this picture you posted in another thread. Your Koni for the front definitely looks different than mine. That part circled is not on my shock. Do you remember if this is what GC modified and added on when you sent your set back to them? Currently my spring perch is right where yours is in that picture, dead at the bottom with no more room to go. I'd be happy to get the ride height right at about where yours is. Not looking to slam the car..

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what did you pay for this headache...
 
I don't get it ... How can anyone drive with something like that. That nothing happened does not mean it can't. If you go over a bump and the spring comes loose but does not settle in its correct position you will most likely loose control of the car and crash. Same with hitting a bump in a corner while riding on the bump stops. Will throw you off the road as well.

Where I live you will loose the registration when a cop notices a loose spring. Instantly.

If the springs are loose the shocks are too long. That is a fact. This is also why Koni offers shocks with custom rebound length or every shock 2cm shorter when you do intend to go for lowering springs on the lower perch. The shock can't work in its intended working range when installed like on the pictures.

It does not mean that the parts used by ground control are bad but the combination is wrong. Just parts put together without thinking more than 10 seconds about fitment.

I am glad we have laws against something like that here!

Bernhard
 
Here is a photo of my dampers, I am running a 7" spring in the rear. It does look like the body of your fronts are not machined to allow the threaded portion to fully seat. Notice how much of the shock body is visible in my photo. Also your bump stops are longer than mine. GC defiantly does not know what they are doing for an NSX set up, I have wasted many emails and phone calls with them. They might have had it correct at some point, but those people are not the ones in the customer service department.
 

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Hate to say this but I've never had a good experience with Ground Control. My buddy wanted to go the "cost effective" route on his bmw and they never stopped making awful noises. My other buddy (also nsx owner) has this on his track crx. After putting on a rear wing the collars collapsed.

The koni damper is proven. The GC solution on the other hand...
 
my point exactly.....is the lower price worth all this...you are better off with koni yellow and zanardi springs,or oem springs and bilstein shocks in the lower price points......
 
AJ here are some pictures of the Comptech Sport setup I have. Let me know if different angles would help:

Here is a photo of my dampers, I am running a 7" spring in the rear. It does look like the body of your fronts in not machined to allow the threaded portion to fully seat. Notice how much of the shock body is visible in my photo. Also your bump stops are longer than mine. GC defiantly does not know what they are doing for an NSX set up, I have wasted many emails and phone calls with them. They might have had it correct at some point, but those people are not the ones in the customer service department.

Hate to say this but I've never had a good experience with Ground Control. My buddy wanted to go the "cost effective" route on his bmw and they never stopped making awful noises. My other buddy (also nsx owner) has this on his track crx. After putting on a rear wing the collars collapsed.

The koni damper is proven. The GC solution on the other hand...

Thanks everyone for the photos and input! This is all very helpful.
 
Wtf? Your springs are way short. I'd send them back. It sounds like you wanna go really low. You should just buy a set of BC-BR coilovers. They are okay but a real deal for the price if all your doing is lowering and not aggressively road racing/ street driving.
 
Wtf? Your springs are way short. I'd send them back. It sounds like you wanna go really low. You should just buy a set of BC-BR coilovers. They are okay but a real deal for the price if all your doing is lowering and not aggressively road racing/ street driving.

choosing springs is far more involved that overall length, so how can you say they are "too short"? My car first had 6" springs but were way too stiff at 750F 650r. they never bottomed, just knocked your teeth loose on small bumps.

When selecting springs you have to figure the amount of force that will bottom them, distance to coil bind (travel) and initial spring rate. How much tension (load) is on them at rest in the car, scales and suspension geometry can be used to calculate this. as you can see there can be a lot to figure.
 
choosing springs is far more involved that overall length, so how can you say they are "too short"? My car first had 6" springs but were way too stiff at 750F 650r. they never bottomed, just knocked your teeth loose on small bumps.

When selecting springs you have to figure the amount of force that will bottom them, distance to coil bind (travel) and initial spring rate. How much tension (load) is on them at rest in the car, scales and suspension geometry can be used to calculate this. as you can see there can be a lot to figure.

I say the springs are too short in this set up due to the fact that the coilover is in the lowest position and the shock is inches away from the top hat. It sure looks like a mixed bag set up. I agree a lot goes into spring rates but come on, did you see the OP's pictures????
 
The springs are the appropriate length for this application and rates. If you read my posts and look at the pictures more carefully, you'll understand why a taller spring simply will not solve anything. In fact make things worse as far as ride height.

No, I don't want to just go low, hardly the case. Lowering the car helps, lowering too much doesn't. I've been an avid autoxer for about 10 years. I have 3 full on autox cars in my garage, this being the newest addition. Heavily involved with the local regions and done a fair share of national events and trophied at every one I've done. This is no new rodeo for me. However, this is a new car for me and I am figuring things out as I go with it. As far as I know, no ones built a "good" autox NSX, mostly because the car isn't classed competitively enough to be worth it. I don't plan to go all out like my other, competitive autox car. But I'll make the best with what I can. I will test different springs, sway bar combinations, alignment settings, etc. I'm already running an "oversize" tire in the front(225/50r17) because the type of tire is one of the best street tires currently out(re71r)- side note, ZERO issue with TCS in this size-. If things don't work at first, I'll find ways to make them work. It's kind of what the autox community does lol

The reason I choose not to go with BC, Megan, Tien or w/e other cheaper, and in this case maybe easier, options are because for autox, Koni and GC are easily the most used and abused suspensions out there. If the car were competitive and I took it that route, I might have spent the money on KW, Moton or any other high dollar suspension. But that's not the case. And as mentioned, the cheaper companies really do not have anywhere near the reputation that Koni(especially) and GC have, nor are they anywhere near as easy to replace parts on or have rebuilt/revalved. This could be a design flaw, but I'll work with GC to figure things out. Worst case is I test and it doesn't work and I do something else. As of now, I've been trying to gather as much info from other users of this setup to see what, if anything, may be different in mine. Also trying to get info to share with GC so we can work together to possibly solve any issues. I was told I'd recieve a call from the owner tomorrow, so we'll see where things go.

To everyone, thank you and I appreciate the help.
 
as you know principles still apply. Good luck on the tighter courses.....lots of push so you spend time lifting and brushing brakes to load the fronts..those 50 series front tires are very tall and as you lower the car will be an issue.
 
I've already done 2 events, at least 16 runs between both events. First event I did was a local scca event, which are on very large, open and fast courses. This is primarily where I will be running the car since the lot allows for faster, less tight/pinch turns. For this event I ran non-comp so I didn't mess with season points. But, I would have landed 2nd out of 15 in BStreet and 4th out of 19 in STR respectively. Behind all people who regularly trophy/win nation events.

Second event was with local BMW club which ran on one of the smallest lots we have in the region. Very tight, pinch turns and decreasing radius turns everywhere. Still placed towards the top on raw times. All of this did surprise me. First couple of events on completely stock suspension and just exhaust. Also first time autoxing a stock NSX(only have done one or two runs in a supercharged NSX with suspension many months before). I didn't have high expectations for this car going in, but things are looking promising after a couple of events. 2nd gear definitely is not great, but it'll do. Also I think my alignment I set helped. Car didn't push much at all.

Front tires do rub a lot but mostly on the fender liners. Have a 5mm spacer and now I've removed the front fenders. Rub on the inside isn't bad, I should hardly ever rub on the inside for the autox events I'm running(never full lock). Might try out a 10mm spacer and roll the fenders. But will see how much negative camber I can get out of the front first.
 
sounds like you have a good handle on your hobby.....post up some vids and keep us updated on what your mods are and what results you get with them.
 
wow as long as they set up courses like that you should have fun....back when I used to do that locally you could fit 3 of our courses inside yours.If every 100th counts keep your roof on.
 
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