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Springs for Koni and FCM

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Old 07-12-2011, 09:17 AM
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IHI
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Default Springs for Koni and FCM

Hi all,

I have Koni-sports / yellow. I also bought FCM top-mounts. FCM recommended not to put the Koni-sport springs on, but I did. Together with the Koni-Sport-kit springs this does not work. Car is sitting way to low, I even think on the bump-stops as it is really stiff. I tried all the perch-positions. I should have listened.

So I put the stock springs back on. Now laugh....
The middle position was recommended by FCM. So I did that and the car was way to high. So I took the shock out for the fourth time and lowered the perch. Just one day later the springs settled and... It was too low. So I took the shocks out AGAIN and raised the perch. Now it is in the middle position.
That is the fifth time I took the shocks out. It is getting fast now, 1-2 hours to do the 4 shocks on the car... I hate it though !

Anyway, I took the car on a trip to France (Europe). Put some luggage in, girlfriend with me. Full tank of gas. When we arrived on the destination the car was as low as it could be. The springs just collapsed. Front and rear. Unloading it didn't do much. But the next morning it was all fine. We took it for a 100 mile tour and again the car sunk back in height. The springs just sag ! Leaving it a night alone, the car raises itself again.

Now I am not all that content with the springs / shocks at all. The bump-stops seem to be just fine, there is no bottoming out. It is progressive in a good way. But when driving on a 40-60Mph straight road the car doesn't seem to compress the spring, it just bounces like it has no springs. Hard to explain but If I have to: it seems like there is not enough mass to make the suspension work. I cannot get my finger on what is happening As I cannot see the wheels moving. I also have to say my other car is a Citroen C5 and has some weird hydraulic suspension system instead of springs. So I might complain about normal behavior. But I have also felt lighter cars (Donkervoort) that had a track setup and were still a whole lot more comfortable.

Anyway, the stock springs have to go as they are to soft for my application and sag on long trips. Either they are old and worn or they are plain to weak.

I am looking at Eibachs Pro kit. Is that any good for my application ? I haven't found the spring rates just yet. I can also turn to the known company's like FM but if there are other springs that are available here in europe that would be more easy (and cheaper).

Does anyone have any recommendations how a decent ride on crapy roads ? in terms of spring rates ? Im I correct that getting the spring rate up would probably make the car more comfortable as it doesn't land on its bump-stops and uses the spring travel better ? Does anyone know at what height the bump-stops begin with the Koni Yellow + FCM mounts ?

Many thanks !
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Old 07-12-2011, 09:40 AM
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what you are suggesting is that your metal springs have turned into warm taffy and lost all yield. I doubt it.

stock springs aren't too soft, they were designed for your car obviously...the konis make no difference in this, as thier valving mimics that of stock shocks.


If the car feels bouncy, then that would suggest no SHOCK at all, not spring.


questions:

when you are tightening your lower shock bolt, are you doing it with the suspension loaded?

did you install the springs on the wrong side of the car?
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Old 07-12-2011, 09:41 AM
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Call FCM back and he should be able to hook you up. Im running his SSS springs 450/300 on koni race/sports and the adjustable sleeves. If you have rough roads id go a bit softer. SSS springs are cheep and have a lifetime warranty from what i understand.
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Old 07-13-2011, 07:15 AM
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Originally Posted by Braineack
what you are suggesting is that your metal springs have turned into warm taffy and lost all yield. I doubt it.
Me too. But it seems like it a lot. I left the car alone for a couple of days and it moves up.

stock springs aren't too soft, they were designed for your car obviously...the konis make no difference in this, as thier valving mimics that of stock shocks.
Agreed. But the 23 year old material might lost its original specs.

If the car feels bouncy, then that would suggest no SHOCK at all, not spring.
No, it is a different kind of bouncing. It follows the road when it goes up and down instead of pushing the wheel down and pulling it back in. I suspect the road pushes the wheel in, but the spring does not push it back out. That gets the suspension on its bump-stops making it so stiff. The shock is set to its soft setting.

questions:
when you are tightening your lower shock bolt, are you doing it with the suspension loaded?
Wow. Good point there ! The shock-rubbers/mounts might be pre-loaded. I have to fix that.

did you install the springs on the wrong side of the car?

In fact, I did. But I noticed when I was doing it and reversed them. It is an easy mistake to make. The longer spring is the softer one as it has more windings. But as it is longer I first placed it in front. It is good now.

Call FCM back and he should be able to hook you up. Im running his SSS springs 450/300 on koni race/sports and the adjustable sleeves. If you have rough roads id go a bit softer. SSS springs are cheep and have a lifetime warranty from what i understand.
Sounds like a good, common, spring rate. I have dropped FCM an E-mail. But I haven't had an answer yet. Maybe he is sick of my whining about my suspension Allthough the FCM stuff worked out superb. It is the springs that leave me down. I should have bought the whole suspension at FCM. He is right. I am ending up spending more. Not to mention pulling the shocks 10 times before getting it right.
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Old 08-08-2011, 03:46 PM
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Ok, still don't like the handling of the car. I think this is what it does: it is too soft, the Koni's are jacking the car down to its bumpstops and then the suspension just turn about solid. Weird enough it takes the springs a long time to extend to its normal length.

I need new springs. FCM won't answer, ground-control say they cannot help me because the Koni/FCM combo cannot handle (their) coilovers.
Leaning towards FM spring set, but will they be long enough?
Other option is to go either for GC or Ebay sleeves. But... What kind of spring and what rate?
Any advice on what to buy? Either FM springs or Ebay sleeves + some kind of springs with the correct rate?
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Old 08-08-2011, 03:53 PM
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Konis have a crap ton of rebound for no reason. They do resist going back to full extenstion due to the rebound, but it shouldn't take "a long time." with the springs pushing back up on the car, they should go back to full extension instantly.


why don't you take a picture of your rear shock when it's "back to normal" then after a drive and it's sitting too low? I just want to see how it looks.
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Old 08-08-2011, 04:53 PM
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Good idea. But it might take a while.

Got a third option that might be the one for me:

At summit I can get a Koni sleeve kit for $85. I can add Eibach springs for $80 each. Autch. I will have to fab my own top/spring seporator or get it from FCM.
But how long should the springs be that I need for this?
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Old 08-08-2011, 04:54 PM
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depends on the rates.

i needed 7" 400 and 8" 250.
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Old 08-08-2011, 05:05 PM
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I was thinking of the FM rates: 225 / 325

I can get 8", so it looks to be good. Should I go stiffer? I wan't comfort as good as it gets on this car.

By the way, I have driven it with the Koni springs. Way too low, but consistent. It was on its bumps I think.
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Old 08-08-2011, 05:19 PM
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This sounds more like shot shocks than springs to me...
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Old 08-08-2011, 05:39 PM
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Well... They have less then 5000 miles on them. One shot, ok. Not all. Car is behaving the same on all 4 wheels. One of the koni's leaked oil out of the top adjuster. I do need to check that one. It leaked because I dialed it into full soft but it is better to turn it 10 degrees of its fully closed or open position (or it will start to leak). It does not leak anymore. But I will check it. Either they misvalved it or it is in the springs. I think the springs are to blaim. Also the car doesn't drop in a 10 mile drive, we are talking about a day of driving on bumpy and curved roads.

I don't think it is that weird. It takes time for springs to settle. But if you compress them for a long time it takes time for them to settle back out?
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Old 08-08-2011, 05:52 PM
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well leaking adjust is not good dude...

are you sure your shocks have any capacity to push back?
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Old 08-08-2011, 05:56 PM
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The thing is... if the springs are going down because they're taffy... i don't see them going back up.

If you can get another set of stock springs, borrow them or something, may as well swap them over and see if the same thing happens. If it does, then you're probably going to have to get those shocks checked out. I wouldn't think that FCM would have messed them up, but everyone makes mistakes at some point, and sometimes it's not even their fault.

I recently had a set of Konis revalved/rebuilt, and my builder had a NIGHTMARE of a time trying to get the things to cooperate due to seal differences, there was a bad batch of seals going around. He rebuilt them literally 3 times in his shop, would throw them on the shock dyno, and they would fail spectacularly.
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Old 08-09-2011, 02:47 AM
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The koni's came from a suppplier, not from FCM. They aren't modified. And yes, I have to test the one that has been leaking, or I will just replace it.

But, let's focus on the problem: the springs are to weak for 2 people and luggage in the car anyway. When I am driving alone it seems to be fine but the chassis seem to move too much. I feel like the spring is pushed in and the bumpstop is taking over. It seems like the car is jacking down even on straight roads. I think I just need stiffer springs anyway.

If i'd use the 800.000.001 Koni kit ( http://www.koniracing.com/sleeves.cfm ) I might be able to swap the bottum spacer with the top-spring-perch. If I add a couple of Eibach springs I should be fine. Or ruled out the springs are to blaim, correct? I think the FM /FCM combo will drop the car too much.

Now, would a 325/225 8" long eibach spring set work? Ride height aim is 13-13,5". I cannot order 7"



Attached Thumbnails Springs for Koni and FCM-redsleevsmall.jpg  

Last edited by IHI; 08-09-2011 at 05:46 AM.
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Old 08-09-2011, 04:15 AM
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Actualy, I CAN get 325 7".
Braineack, what is your ride height, what top-mounts do you use and how high are your perches? Does your car compare to my 1989 NA with NA Koni's and FCM tops?

I also have to choose between the 800.000.001 and 002 kit. The 001 kit would act as the lowest support ring for the NB mounts. But the surface is not flat. It might not support the rubber for the topmount enough. The topmount would get loose causing the shock shaft to go up and down in the topmount ? The 002 kit has a flat surface but it is not a ring anymore, it is 15mm thick and takes this space of the top-mount nut. That would do no good. I could mill them out to another proportion like 5mm or so. That would make a better surface for the top-mount and a strong spring top.
Then there would not be an isolator between the spring and the top mount. Would that make the spring very harsh on the car ? That is just what I try to avoid.



or



An other problem: the spring now rests on an isolator that rests on the topmount. By getting the Koni upper perch the spring will rest on the FCM rubber that rests against the topmount. I don't think that is a good thing. It will have to take the full weight of the car.
I could mill the part off where the spring normally rests on. Then the top-perch would only be a center-ring to keep the spring in the middle ?

The FCM topmounts / bumpstops are good, but it leaves not a lot of compatible springs to choose of, as they lower the car. Fitting aftermarket springs will get the car on its bumps right away as they are shorter then the stock thing. That is the whole problem really.
Attached Thumbnails Springs for Koni and FCM-threadedsmall.jpg   Springs for Koni and FCM-threade1small.jpg  

Last edited by IHI; 08-09-2011 at 06:25 AM.
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Old 08-09-2011, 07:32 AM
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why would you even use the topmount thing?
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Old 08-09-2011, 07:51 AM
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Originally Posted by Braineack
why would you even use the topmount thing?
Here is a pic:



How would I have the spring seated / centered, as it is 2 1/4 " inner diameter. Most of the ebay kits use 2,5" inside diameter springs. I did find this at the Koni site:
Nylon 2.25" to 2.5" spring adapters (2 needed). Would that mean I could run 2,5" springs on these sleeves ?



The stock springs are little over 3".

Is there an advantage or disadvantage using a smaller diameter spring ? I run 195/50/15 so space is not an issue.

In other words: the Koni sleeves would fit nicely over the shock body, other sleeves I would have to shim with O-rings. Looks like 2,5" springs can be used.
Attached Thumbnails Springs for Koni and FCM-nb_shockmnt.jpg  

Last edited by IHI; 08-09-2011 at 08:10 AM.
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Old 08-09-2011, 08:37 AM
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I have found this:
http://www.cardomain.com/ride/234349...-houston-tx-us
Why does GC say their stuff do not work for me ?
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Old 08-09-2011, 08:40 AM
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GC said that?

No clue, those are the most common sleeves for the konis....more popular than Koni's own sleeves.

I were buying the Koni sleeves, I'd only get (4) 80.0000.0005 and (4) 80.0000.0006. Then you can get (4) of the 15.29.04.003.0 so you can put 2.5" springs on it.

I wouldn't personally do anything to the mount for a spring isolater, but that's just me.

I also wouldn't buy the Koni sleeves because that adds up to around $70 a corner.


The Ground Control sleeve kit is $350-399 with springs: http://flyinmiata.com/index.php?dept...0%20%201990-97



This is a cheaper option: ALL64146

$35 a corner. The descriptions are all the same for each manufacturer, but the Koni shocks are 42mm OD, it says these are for any 2" (50mm) shock, but that part number is for konis specifically. If anything, you stuff rubber gasketing between the shock body and sleeve, lots of people do that with universal sleeves.

Still at $140 with sleeves alone, you'd need to find $60ea springs to make it worth the cost of just getting the GC kit.

Last edited by Braineack; 08-09-2011 at 09:14 AM.
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Old 08-09-2011, 09:01 AM
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I did another request on GC to get back on me. This is what they said:

No. Those rates wont work (I mentioned 225/325), the upper mounts are not really compatible with a coilover kit. (There is a better way to do this, but I dont think you want to start all over again).
Our kit would not be a solution to the problems you have described. Thank you.
Maybe he had a fight with his wife last night or so.. I just don't know.
The only thing that could be better in the GC kit is this:

That might not be proper for GC. But I would be able to make something nice out of alloy or nylon on the mill to have it proper seated.
As on the spring rates, why would GC those rates won't work ?
The only thing I can think of is that I told them to much. "GC, can I get a kit with 225 / 325 springs for Koni" maybe would have worked out better....

Does anyone knows the difference between the GC NA and NB kit ? This wouls make the most economical and best quality kit anyway.
Thanks !
Attached Thumbnails Springs for Koni and FCM-23434970021_large.jpg  
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