# Changing Stock schocks for Koni FSD



## anE934fun (May 10, 2008)

Snipe656 said:


> But then based on prior comments in this thread they are not one size fits all but instead for sports springs?


I am not sure I understand your question. The fittings on the FSDs that enable the damper to be mounted to the suspension on the E90 are the same regardless whether you have a Sport package or not (hence my comment about 1 Koni part number). You can fit Koni FSDs to your E90 whether you have the Sport package or not. Stated another way, there is no exclusion for FSDs for non-Sport package E90s. There is an exclusion for FSDs for AWD-equipped E90s.


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## Snipe656 (Oct 22, 2009)

anE934fun said:


> I am not sure I understand your question. The fittings on the FSDs that enable the damper to be mounted to the suspension on the E90 are the same regardless whether you have a Sport package or not (hence my comment about 1 Koni part number). You can fit Koni FSDs to your E90 whether you have the Sport package or not. Stated another way, there is no exclusion for FSDs for non-Sport package E90s. There is an exclusion for FSDs for AWD-equipped E90s.


This:



cssnms said:


> Axel proceed with caution when considering changing out shocks without addressing springs. I would suggest replacing your springs at the same time with a spring with a higher spring rate e.g. either zsp springs, EPK's or similar. The shock/spring system is engineered to work in concert. Shocks are designed to manage the spring rates they are paired with. A shock that cannot handle the rebound and or dampening of a stiff spring will result in a bouncy ride and vice versa. I can't tell you how many people I have read about that only did one without the other only to end up paying for the install all over again to have matched springs installed. Just my $.02
> 
> Have you considered the BMW Performance suspension kit (springs and shocks together)?


Is that not saying that the FSDs are not engineered to work correctly with non-sport springs? Meaning sure they can bolt in there but will not ride/handle correctly because the FSD is designed to work with a "tighter" spring.


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## cssnms (Jan 24, 2011)

anE934fun said:


> One size fits all (same Koni part #) as regards FSDs for Sport vs. non-Sport edition E90s.


Well that maybe what the manufacturer says, but in reality one shock does not fit all spring rates.


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## cssnms (Jan 24, 2011)

Snipe656 said:


> This:
> 
> Is that not saying that the FSDs are not engineered to work correctly with non-sport springs? Meaning sure they can bolt in there but will not ride/handle correctly because the FSD is designed to work with a "tighter" spring.


One size does NOT fit all, it never has when it comes to performance suspension systems. Koni might tell you otherwise, but they are in the business of selling shocks. Personally, if it were me, I would buy a shock and spring that are designed/engineered to be paired with one another.


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## Snipe656 (Oct 22, 2009)

How are the suspensions setup on these cars anyway? Do you end up removing the springs to replace the "dampners" anyway?


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## anE934fun (May 10, 2008)

Snipe656 said:


> Is that not saying that the FSDs are not engineered to work correctly with non-sport springs? Meaning sure they can bolt in there but will not ride/handle correctly because the FSD is designed to work with a "tighter" spring.


I think that css is being pedantic. While the points raised may be applicable if you are wanting to build a car that will run the 'Ring with the shortest possible lap time, in the 'real world', the Koni FSDs will work just fine with Sport and non-Sport E90 suspensions.


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## anE934fun (May 10, 2008)

Snipe656 said:


> How are the suspensions setup on these cars anyway? *Do you end up removing the springs to replace the "dampners" anyway*?


Yup. On the front, the strut/damper has a 'hat' (don't know what the technical term is for the flange/whatever) that holds the spring.


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## Snipe656 (Oct 22, 2009)

anE934fun said:


> Yup. On the front, the strut/damper has a 'hat' (don't know what the technical term is for the flange/whatever) that holds the spring.


Is the rear the same way? I seem to recall my old Honda and Galant were both this way, so you ended up disassembling everything and from a labor stand point it would take no more time to do springs when doing the struts/shocks/whatevers.


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## cssnms (Jan 24, 2011)

anE934fun said:


> I think that css is being pedantic. While the points raised may be applicable if you are wanting to build a car that will run the 'Ring with the shortest possible lap time, in the 'real world', the Koni FSDs will work just fine with Sport and non-Sport E90 suspensions.


Not at all.... BMW engineers spend countless hours designing the suspension systems for these cars and that includes pairing the right springs and shocks together. Shoot, they will even put a slightly different set-up on a car depending on the options (added weight).

Why on earth anyone would think they can just slap any old shock on their car without the potential of negatively impacting the suspension geometry is beyond me. :dunno:


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## Snipe656 (Oct 22, 2009)

I get that BMW engineers a complete package but what I do not quite get is how can we say for certain what Koni engineers their parts for in regards to spring selection.


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## cssnms (Jan 24, 2011)

Snipe656 said:


> I get that BMW engineers a complete package but what I do not quite get is how can we say for certain what Koni engineers their parts for in regards to spring selection.


You're right, but they can't engineer a single shock for 2 different springs, it just doesn't work that way. My best guess is they tried to compromise which means the shocks will not necessarily be excellent for any one application. In that case, why not stick with OEM? At least you know they are designed for your car/springs.


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## anE934fun (May 10, 2008)

cssnms said:


> Not at all.... BMW engineers spend countless hours designing the suspension systems for these cars and that includes pairing the right springs and shocks together. Shoot, they will even put a slightly different set-up on a car depending on the options (added weight).
> 
> Why on earth anyone would think they can just slap any old shock on their car without the potential of negatively impacting the suspension geometry is beyond me. :dunno:


We will just have to agree to disagree. In the mean-time, everyone who has installed a set of FSDs on their E9X (equipped with both Sport and non-Sport package) cars in the non-Diesel universe are raving about the improvements they are experiencing in the 'real world'. There are a number of threads that back up that circumstance.


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## cssnms (Jan 24, 2011)

anE934fun said:


> We will just have to agree to disagree. In the mean-time, everyone who has installed a set of FSDs on their E9X (equipped with both Sport and non-Sport package) cars in the non-Diesel universe are raving about the improvements they are experiencing in the 'real world'. There are a number of threads that back up that circumstance.


Look I am not knocking your Koni's they are good shocks, shoot I considered them myself when I was in the process of figuring out what I was going to do with my suspension system. I've seen just about every review out there - I am very active on the other board.

Most people that swap to just Koni shocks (no springs) are doing so because their original shocks are shot or are approaching the end of their useful life so they are looking for a replacement alternative to stock shocks. The others who installed Koni did so early in the process in an effort to actually try to improve their car's handling characteristics and thus paired them with a tighter more performance oriented spring.

That being said, for the most part reviews are favorable and certainly one's perception is reality. However, I would not say for those that have changed out just their stock shocks that some daily driver's impression is any credible review of how well the Koni shocks improved or negatively impacted one's suspension geometry.

The real question here for Axel is; What are you trying to accomplish by swaping out relatively new and perfectly good OEM Bilstein shocks for Koni shocks? If it's an improvement in handling you are after, you are only looking at 1/2 of the equation and anyone that tells you otherwise does not know what they are talking about.

Look at either a coilover or spring and shock kit that are engineered to work together


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## cssnms (Jan 24, 2011)

Axel take a look at this kit, it is awesome combo if you want to maintan the daily driveability of your car while at the same time improving the handling and lowering the stance a bit. Best of all it is designed/engineered by the suspension guru's at BMW.

http://www.trademotion.com/partloca...fo&PartID=755902&siteid=214672&catalogid=4462


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## Axel61 (Mar 10, 2011)

Thanks Chris, as I stated before I used the FSDs on my 02 MCS which had the sport suspension and after the swap the car handle FAR better than stock yes, STOCK ( I left the sport springs on, just in case anyone asks me about them), to put it this way I let 3 different individuals drive MCS and two inmediately purchased the FSDs and believe or not they were STOCK MC not MCS, the third person whom happens to be JP Performance out of Puerto Rico the owner Jean Paul had an MCS an after he test drove my car he was upset he had sold the it 2 weeks earlier. He loved the MCS he had to sell it cause his back was paying the price. Mind you this guy deals with Porsche and other high end vehicles and he is the offical M7tuning.com installer and dealer, also Peter Hovarth from M7 test drove the car and was amazed in how the car drove and handle. All that said I firmly believe my vehicle will ride better and handle these freaking rodes of my Island. I CANNOT say wether it will work with my 335d since I have NOT heard from any other D about this issue. I will keep all of you posted as I have with intake, ECU etc etc. Gracias for inquiring.


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## Axel61 (Mar 10, 2011)

BTW @Chris the purpose for making changes is because I have ventured to anohter place with my 335d and my defunct 02 MCS and I attest for these products, so far RENNtech has not let me down and we'll see if FSDs can come up to the plate. Will keep u all posted


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## anE934fun (May 10, 2008)

Axel61 said:


> Thanks Chris, as I stated before I used the FSDs on my 02 MCS which had the sport suspension and after the swap the car handle FAR better than stock yes, STOCK ( I left the sport springs on, just in case anyone asks me about them), to put it this way I let 3 different individuals drive MCS and two inmediately purchased the FSDs and believe or not they were STOCK MC not MCS, the third person whom happens to be JP Performance out of Puerto Rico the owner Jean Paul had an MCS an after he test drove my car he was upset he had sold the it 2 weeks earlier. He loved the MCS he had to sell it cause his back was paying the price. Mind you this guy deals with Porsche and other high end vehicles and he is the offical M7tuning.com installer and dealer, also Peter Hovarth from M7 test drove the car and was amazed in how the car drove and handle. *All that said I firmly believe my vehicle will ride better and handle these freaking rodes of my Island. I CANNOT say wether it will work with my 335d since I have NOT heard from any other D about this issue.* I will keep all of you posted as I have with intake, ECU etc etc. Gracias for inquiring.


You must have ignored my earlier posts. Starting with post 15 I have been commenting about my experience with FSDs on my d. There are other Festers with gasser E9X cars that have swapped out the stock shocks for FSDs and are raving about the improvement.


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## Axel61 (Mar 10, 2011)

@anE934fun, sorry about this and my apologies. You posted right after I did on #14. How much do you enjoy your FSDs i am planning in leaving the Non-sport springs


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## anE934fun (May 10, 2008)

Axel61 said:


> @anE934fun, sorry about this and my apologies. You posted right after I did on #14. How much do you enjoy your FSDs i am planning in leaving the Non-sport springs


As BF member Captain Audio posted in one of the threads about FSDs - the FSDs are what BMW should have included for shocks when the cars left the factory. My first experience with FSDs was on a 2005 MCS. The ride was killing my back. After the FSDs, everything was fine. Everyone I know who have swapped out the oem shocks for FSDs has been amazed at the result. Good luck on your swap. :thumbup:


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## Axel61 (Mar 10, 2011)

I am 1000% agreable with you my old 02 MCS handled, performed and rode WAYYY better than any other MINI in Puerto Rico that is a reason Im back the FSds.


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