How Shocks Work - Changing rebound force on a Koni with internal adjuster - BMW E46 M3, v2.34

[@craigwatkins7011]

You're right, there are other video's but yours is very clear, the detent part especially. Thanks, this really helped.

[@SuspensionTruth]

You're welcome, Craig.

[@GarrettGiuffre]

I couldn't find any information on this till I stumbled upon your video! much appreciated!

[@SuspensionTruth]

Thanks, my pleasure!

[@RwP223]

All the other videos make it look easy using an uncharged example shock to demonstrate. In reality it's a struggle fighting the gas pressure, got to fixture the shock good too.

[@SuspensionTruth]

Yeah, a degassed damper, which makes cavitation even worse, would make the process much easier. I imagine that Koni intended these to be adjusted while on the vehicle so the top of the shock would be indexed to the chassis and you would disconnect the bottom from the hub then push it upward to engage the detent. That would be a bit more stability and better fixturing in that case.

[@7beast298]

Will this also work on my orange koni str.t?? On my e36

[@djglobol]

Thank you for this info

[@numinous4789]

I've heard from ground control that you're supposed to adjust these on the actual degrees of turning, NOT on the amount of time for the shaft to rebound. I didn't fully understand their explanation why, but they were quite adamant that degrees is correct, and rebound time is wrong. Can you speak to this?

[@SuspensionTruth]

Timing the shaft rebound is only showing you very low speed behavior and I'd consider that an unreliable way to set the damper. You'd need a shock dyno to get them set consistently that way. Measuring the degrees of rotation is more accurate so yes, I understand that they'd insist you do it that way. The dampers may not match perfectly, but they should be close enough left-to-right to provide similar levels of damping.

[@frankfitzpatrick5300]

Hello & thank you my friend , Your Excellent wisdom as usual , QUICK QUESTION : I know you hate lowering springs , but my shocks on my 1995 NA8 Miata are N/G & I have Koni yellows with your F.CM. Koni yellow bump stop kit ready to install on my 1995 Miata . Should I use the RACING BEAT springs I have been given or use the STOCK SPRINGS 1995 SPRINGS or R PACKAGE SPRINGS or I can trade for for FLYING MIATA springs or a spring of your choice . Spirited mostly daily driven , some competition car with former SCCA , IMSA driver . Thank you , looking forward to your professional advise . Sincerely , F.J. Fitzpatrick

[@SuspensionTruth]

Hey Frank, I didn't see this comment so not sure if my feedback matters at this point! For the Koni springs and best performance / durability, I would choose the Flyin Miata springs over Racing Beat. For smoothest ride, I would keep the stock springs. The Racing Beat springs are notorious for sagging and since they're fairly soft springs you will be bottoming out in no time. This applies to Eibach springs as well. The FM springs are generally well-made and have good spring rates for entry level street/high-performance driving.

[@fkporsche1]

Thanks for sharing your video! I have a ND Miata It has too much body lean, and OEM soft ride like a Buick. The stock spring rate: front 159, rear 100. My local Miata tuner shop has a set of roadster sport springs front 300, rear 200 with koni yellow adjustable. Do you think this is a good set up? I know koni recommend to set it at softest setting at first. But I want to know what is the best way to set my shocks: front and rear foe best spirited driving with comfort? Not harsh. How is it compare to bilstein shocks? As they are option to a few of Japanese car manufacturers and German car manufacturers. I had koni shocks installed 30years ago in my 1985 BMW 325e. It was quite new in its time for adjustable shocks. (Turning the white knob type). Also, I had a set of OHLIN coilover on my previous Miata. It has a crisp feel, although it can be a bit harsh. Please give comment on your preference koni or bilstein. ? Cheers 🦅🦅🇺🇸

[@SuspensionTruth]

Hi Frank, I'd be happy to help you but it's not just about throwing stiffer springs on there. The shocks have to be working properly otherwise the whole suspension isn't going to behave as a harmoniously unit. We have had excellent success with our custom-tuned Bilstein dampers for all models we work on. We've done about 5 ND Miatas already, including several with stock springs and stiffer front bar, and one coilover setup for a customer who said he wished it came from the factory that way! Please use our contact form and send me a note so we can communicate directly. fatcatmotorsports.com/contact_elite.htm Shaikh

[@fkporsche1]

Suspension Truth - 👍🏻👍🏻 🦅🦅🇺🇸

[@fkporsche1]

Suspension Truth - please send your contact information. I would like to check in with you at time. ([e-mail])

[@SuspensionTruth]

Hi Frank, you can email contact us through our website: www.fatcatmotorsports.com/fcm_elite_consult_form.htm or www.fatcatmotorsports.com/contact_elite.htm#

[@suleimandc]

Thanks for the video. None of the other guides that I have seen said anything about a detent groove. I'm going to remove my shocks and adjust again. What was the tool that you used on the top?

[@SuspensionTruth]

+Suleiman Da Costa I call it a detent, it's essentially a keyed feature so you can engage the adjustment mechanism. That's a machined round steel adapter. It's threaded onto the shock shaft to secure the shock shaft to the load cell on our Roehrig dyno.

[@terrencelawrence5007]

How many detents untill full soft from full stiff?

[@SuspensionTruth]

No longer have the damper. Generally I've found Konis have about 1.5 turns of adjustment.

[@terrencelawrence5007]

@@SuspensionTruth So turn front and rear same amount of turns for even damping correct?

[@SuspensionTruth]

You'd hope so but that's rarely the case in my experience. Most suspension that have knobs are deficient in their inherent design. A Koni damper has a bias toward rebound, which ends up causing 'jacking down' or 'packing down,' which is a loss of suspension travel after each successive bump/dip. The stiffer the rebound adjustment, the more jacking down. You ideally want to MINIMIZE damping bias in either rebound or compression. Most twin tubes can NEVER develop enough compression to cause problems (only monotubes are really able to displace enough fluid to generate useful amounts of compression). So a typical twin-tube like a Koni will rely on more rebound. Even at full soft, a typical Koni will jack down. Most factory dampers also jack down, but the Koni and others (KYB, Tein, etc.) give you more room to hang yourself, so to speak. The ideal setup is one that has Flat Ride behaviors in the springs (Fundamental principle #1) and ALSO maintains that Flat Ride as the vehicle compresses the suspension and engages the bump stops. Most vehicles have stiffer front bump stops than rear (one reason why they 'understeer' from the factory). So you have to add the bump stop spring rate to the main spring rate and then do some math to get the actual wheel frequency for the front suspension, then the rear suspension. When you have Flat Ride and maintain Flat Ride, then your need for damping to 'control the suspension' is actually MUCH LESS than you think. This means you can run your dampers SOFTER and get better grip and better overall composure/ride quality. So taking a high-level view beyond your question about what to turn the Konis to, you really need to look at the ride frequencies and get those correct, then decide how much (or how LITTLE) damping you need and adjust the Konis accordingly. The probably won't be 'matched' and that's okay. I would start with both at full soft and begin adding rear, then add front once you get to say 1/2 turn in the rear.

[@terrencelawrence5007]

@@SuspensionTruth thanks I'm waiting for eibach springs to arrive. I have new bump stops Koni shocks new top hats from and rear new rubber spring pads front and rear waiting for me to assemble. I'm hoping that I didn't make the mistake of a worse ride.. I'm happy with the OEM setup but think it could possibly be made better 🙂

[@SuspensionTruth]

The OEM setup can definitely be made better, but having each component work together is what gives you that excellent result. Unfortunately, most of the time we end up buying separate parts and then hope they work together but that's rarely true. Even buying a coilover from a 'respected vendor' leads us to think someone else did the hard work to figure out what really needs to be changed so you're making an improvement. Again, the results are tighter handling but usually a degradation in ride. It doesn't have to be that way. This is why I focus on understanding what each component does at a fundamental level, then deciding what needs to change FIRST, then SECOND, etc. A lower spring like the Eibach is going to drop the car more than it should for as soft as it is. Even the '20% stiffer than stock' is far too soft for a 1 inch drop (typical). It needs to 50-70% stiffer than stock so you're not just running around on the bump stops even MORE than the OEM suspension. Remember, the OEMs have MUCH bigger budgets (usually) than aftermarket companies. They have to meet a lot of criteria in testing, as well as customer expectations. For aftermarket components, usually it's 'cheap, lower, pretty color.' Not being mean to anyone, but I know how we as enthusiasts often think :) If you don't know how the Konis behave, how can you know if you'll have a better result than stock? if you don't know how the stock dampers behave, how do you know if the Konis are even worth looking at? Or a Bilstein, even? I had to spend years studying and testing to realize that OEMs care more about marketing and creating an 'illusion of performance' rather than giving us really fast, capable machines. Whatever a factory car can do, a suspension by someone who knows their sh!t is going to make it way better. Three key elements - #1 - getting Flat Ride in the springs for the WHOLE range of travel. #2 - damper compression vs. rebound behavior. Are you driving NASCAR circle track (rebound biased) or do you want Rally Car for the real world (better proportioned compression and rebound). #3 - minimized damper nitrogen pressure and rod force. This is where the 'high-end' dampers and monotubes fail very miserably, because vendors like AST, Moton, MCS, and to a lesser-extent Bilstein, Ohlins, KW Monotube all end up with too much rod force which is like over-pressurizing your tires. Makes the ride choppy and the grip less consistent. Worse tire wear, too! Just adds a background vibration which rattles and jars you around. It can be subtle, or blatant. If you start by figuring out those first three elements, the other components are much easier to select. I wish it was an easier method, but like many things in life you only know what you know. When you don't know, you can just guess and hope - maybe things work out. But if you are asking questions and wanting to make an informed decision you have to dig deeper. That's why I created this channel, to help people think, examine, and look at the suspension as a whole, rather than throwing a bunch of parts at it that will probably not work together well.

[@Benjaminjay81]

whats those 2 holes for on the horizontal top part of the shock

[@SuspensionTruth]

For disassembly.

[@DJNaturaultone]

Hey man. Is this recommend before putting springs and top hats on ?

[@SuspensionTruth]

This vid is for the rear shock which for the BMW is separate from the spring. For some vehicles the rear spring is mounted on the shock. For this style Koni adjuster you need to have the damper off the car to do this.

[@DJNaturaultone]

Suspension Truth thanks for the fast reply. I have the koni with the top adjusting knob. I put it on full stiff and It hits bumps really hard. I think I have to put it between soft and stiff and try that. They did mention in other videos it's supposed to be backed out a little and not fully stiff.

[@SuspensionTruth]

Gotcha. Yeah full stiff is going to be pretty rough in most cases. I would run it FULL SOFT to begin with if you're using a stock spring or a mild lowering spring. The knob will indicate the direction for FIRM (usually it's COUNTER-CLOCKWISE). I would turn it fully CLOCKWISE to full soft. Different shocks have different # of turns but usually about 2 to 2.5 turns from stiff to soft.

[@DJNaturaultone]

Suspension Truth thanks again. I just reinstall them. Gonna take it for a drive and see. I'll post again later thanks again.

[@DJNaturaultone]

Suspension Truth using the ground control springs it came with and extended top hat's. My car is a 1996 civic btw.

[@peted2331]

thanks mmmmannnngggg!