Having an issue with adjustable Koni shocks and ECS Tuning.

[LockDots]

I purchased the 1140 kit and I'm installing the rears right now. I noticed that I have to leave one shock at full soft and the other at full stiff in order for them to rebound at the same rate once compressed. Will there be a difference in feel?
Considering leaving them in if that's the case.

I just got off the phone with ECS Tuning and they told me that if I ship them the shocks and they evaluate and deem something wrong with them that I'd have to pay a difference between what they go for at full price compared to what I got them for because I purchased them when they were on sale. I think this is BS. Regardless of what I paid for them I paid for a working set and no where on their site does it say anything about exchanges on products requiring difference in cost for an exchange of/for the same product.
Am I overthinking the damping issue and should I match them up as best I can and leave them in or should they both rebound at the same rate if set the same amount of turns on both and thus fight with them about an even exchange?

[bimmershark]

It's likely that the stiffer one is for the driver's rear.


To compensate for that fat booty you're​ rocking.

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[LockDots]

It's likely that the stiffer one is for the driver's rear.


To compensate for that fat booty you're​ rocking.

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lol thanks

[NoLastName]

Are you comparing rebound speed with the shocks off the car? That won't be accurate because there's no spring force acting on the dampers except a small amount of internal gas pressure.

[LockDots]

Are you comparing rebound speed with the shocks off the car? That won't be accurate because there's no spring force acting on the dampers except a small amount of internal gas pressure.

I am and I found a very big difference between the two. That being said I have no suspension or mechanical engineering training so I'm only going off of what I can "test" in my garage at the moment. See post coming up very shortly.

[LockDots]

A few of things I discovered recently:

1 - I tested each shock independently on a bench vice so that no other factors contribute to the measurements found. The rebound dates were measured in seconds from fully compressed to fully extended of each shock are as follows (build dates derived from date codes listed on shock bodies):

Shock 1 with build date of Feb/March of 2016

Full soft setting = ~5 seconds
Full stiff setting = ~10 seconds

Shock 2 with build date of October of 2015

Full soft setting = ~12 seconds
Full stiff setting = ~50 seconds

I'm leaning towards Shock 1 being the problematic one. 5 seconds of difference in rebound between full soft and stiff really isn't much, especially when compared to almost 40 seconds difference found in Shock 2.

2 - I strongly discourage purchasing from ECS Tuning without first fully reading every single policy they have on returns/exchanges/warranty. I purchased this kit because it was at a good price and listed as being on sale. Nowhere on the product's page did it say anything about the warranty on this item being different from any others or even itself at regular/full price. Therefore, I figured they would stand behind their product. Unfortunately only after digging through their website did I finally see that any products that they sell at reduced price/on sale/clearance are exempt from their warranty. In other words, because I bought this kit when it was on sale I don't have a warranty on it. aka purchased as-is.

3 - NoLastName brings up a good point. These are being tested outside of the car and therefore what I find in my "garage testing" may not mean anything at all. I don't know if I'm even supposed to see a difference or if it even means anything. I'm beginning to think that the damping rate affects how fast the shock is allowed to compress and rebound with relation to the body/spring movement as opposed to operating in "open air".

I'd love those with more knowledge in suspension to chime in. I really don't want to have to go through the hassle of returning/exchanging these if my "testing" really doesn't mean anything or doesn't apply to what I'm seeing.

[TostitoBandito]

You might try to work ECS a little more. What they told you seems unreasonable, and if you get someone else or someone higher up you might get different treatment. You got them on sale and if they were defective then they should replace them for you at no extra cost.

I recently had the opposite experience with them with one of their new bronze caliper bushings. It had slid out of alignment and spun after installation, and after writing them an email describing the issue they immediately overnighted me a replacement bushing and guide pin.

[NoLastName]

I think you're overthinking it. Small differences in seal drag, gas pressure and manufacturing tolerances can affect how quickly a shock extends when there's no external spring working on it. What matters is how the damper functions when subjected to normal operating forces - which are HUGE compared to the small amount of gas force inside the shock acting on the shaft area. To replicate operating conditions you really need a shock dyno. Even two of the same exact shocks can have slight differences in compression and rebound. A race team using off-the-shelf shocks would likely dyno a bunch of them and then match up sets based on the dyno plots. For street use you don't need to go that far

I would install them, match settings left and right and see how they work. If there's something drastically wrong with one of the shocks it should be pretty apparent.

[scooper]

I'd be inclined to say shock 2 is the problem...if there is a problem. You need to be testing for high speed rebound which simulates real world driving conditions not low speed rebound. Konis are low pressure gas dampers. If you do send them back ask them how they would test it. Better yet if you think you have a defective set, send it to Koni USA.

[Gordo0208]

Install them, I had the same issue. Sent them back to Koni only for Koni to take 4 weeks to ship them back and tell me they were fine but not adjusted equally (rebound setting)
I went full stiff when they came back. No issues.


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[matthugie]

I think in this case your best bet is to go directly to Koni if you can. It can be hard to get the middle man to warranty a defective part as they have to then file the same claim against the manufacturer, and warrantying it up front adds risk.

That said, I've had a few dealings with ECS and their returns/shipping issues people and they've been fantastic. They aren't the closest geographically or fastest to get to me, but any issues I've had they have had exceptional customer service so I keep buying from them. Also, in addition to my e36 I have two VAG products, so it's simpler if I can order everything I need for all 3 cars from one source. As an example, I was short shipped an item (well, pair of items), called them up and the replacements were overnighted without even asking for anything to be expedited. Granted, USPS lost the first order so it had been a while since I was supposed to get it, but that wasn't their fault and they still stepped up to the plate.

[mitch500]

I hate ecs they are such cheap asses. Also they gouge you on shipping to Canada.

Dosnt help you but little rant.


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[tjm3]

The only way to compare two shocks for operation and adjustment is a shock dyno. Find a place that has one or just give them each a turn and a half and bolt them in.

[SamGrant951]

^ agreed, I tested an old old rusty rear set that I pulled off my 944 racecar, they were uneven and barely looked responsive when tested by hand. Had them tested on a shock dyno and they were still in spec. Bolt in and go.

[jhott66]

Pushing down on a damper and watching it rebound is pointless. There is very likely nothing wrong with your dampers. Install them and move on.
ECS Tuning is a good business and supports a wide range of car brands, not just BMW. I have had good dealings with them.


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[RRSperry]

Nobody is running enough spring to warrant full stiff. Set them just off full soft as a start.

[Gene V]

Nobody is running enough spring to warrant full stiff. Set them just off full soft as a start.

or maybe a half turn from full soft at most...

[jhott66]

Nobody is running enough spring to warrant full stiff. Set them just off full soft as a start.

Agreed unless there are linear high rate springs involved.
I'm guessing, though, that the OP does not know what the spring rates are.


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[Gordo0208]

Agreed unless there are linear high rate springs involved.
I'm guessing, though, that the OP does not know what the spring rates are.


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You guys might honestly be right about warranting full stiff but I haven't had any problems and NYC streets are NOT forgiving =]


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[TostitoBandito]

For anyone's reference, Ground Control set up my Konis 1 turn off full stiff in rear and 3/4 turn off full stiff in front to go with 440/550 spring rates. Works fine on the streets, though I run them full soft rear and slightly off full soft front during the rainy/cold seasons because I may as well.

[Braymond141]

Your problem is that shocks do not function like you think they do. You can't test them the way you have and 100% they are fine. Install them with equal settings and stop worrying about it.

[LockDots]

It's definitely reassuring to know that my tests are meaningless with regards to the shocks' operation. I come from an electrical engineering background so mechanical and especially suspension are foreign to me.

Thank you to everyone for your input. The shocks' are being used with Eibach springs. I'm not sure of the spring rates though I'm sure I could find out easily. That being said, I set the shocks to a half turn from full soft and installed them.

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[Braymond141]

Enjoy them!

[notMpowered]

I noticed the same thing with a set of KWs before I put them in. They function as they should, but I was worried as well when I opened the box. I'm sure you already know, but heres one more vote for reassurance that all is well.

[ECSTuning]

Sorry to be a bit late to the party. As the guys said the shocks are designed to dampen under load, so the test off the car isn't 100% accurate. Now that you have them installed if you still feel there is an issue, please reach out to me and I'll help you work with my customer service staff.

-James